MECHANICAL ENERGY STORAGE

Field

This invention relates to creating potential energy using surplus power from the grid and conversion of the potential energy to kinetic and electrical energy.

Background

[0001] There is a gap between power demand and photovoltaic supply based on sunlight hours. Sunny days produce a lot of solar power, but solar energy generation, both thermal and photovoltaic, may not be matched to demand with production on cloudy days being as low as 10% of production on sunny days. Similarly wind power generation is directly correlated to the prevailing wind velocity. Low wind speeds results in low production and high wind speeds results in high production. There is a diurnal profile of both wind and solar and a mismatched diurnal profile of demand. Energy storage enables matching of the demand and supply profiles and the efficient operation of the grid.

[0002] Additionally, there is a sharp increase in the price of electricity when the load outstrips photovoltaic (PV), thermal solar or wind generation, which can often be around 5 times average electricity pricing and can be hundreds of time in peak air conditioning days so providing relatively low capital cost storage that enables production of potential energy during periods of low electricity pricing and release of the potential energy to electrical energy and sale to consumers during times of higher electricity pricing can be highly efficient. On one extreme, electricity providers are paid for being able to respond quickly to stabilize the grid, usually in milliseconds, and at the other extreme, grid operators need electricity when the sun isn’t shining and generating solar power and the wind isn’t blowing and producing wind power. There are a number of commercial opportunities to provide short term energy from storage with a slower response time.

[0003] As an example of the level of storage required for nations to rely on renewable energy sources, The Australian National University has estimated that if Australia is to rely on renewable energy sources like solar and wind, 450 GWh of energy storage will be required. This level of storage will vary for other nations subject to demand and both wind and solar access however in all cased large scale storage capacity will be required.

[0004] Gravity storage of energy is a partial solution. There are several ways gravity storage can be implemented.

Pumped Hydro Storage

[0005] In pumped hydro systems, energy is recovered when stored water is released from a higher elevation reservoir and flows down via gravity to a lower elevation reservoir, passing through a turbine/generator producing power. When there is surplus or cheaper power, water is then pumped back up from the lower to the higher reservoir using electricity and the process is then repeated. There are plenty of sites worldwide where pumped hydro has been implemented and where pumped hydro could be implemented. However, social and environmental issues need to be addressed and the cost and time to construct dams are significant.

A Large Scale Lithium Ion Batery Comparison

[0006] The historical cost of the Tesla Battery AUD$90m for a 129 MWh battery, which is approximately $700,000 per MWh storage capacity. For the Australian example, the current market value 450GWh of lithium ion storage is $313 billion but this is academic as the batteries required do not exist. Lithium ion batteries have a limited number of recharges before they start losing storage and recycling the batteries is difficult and expensive.

The GPM (Gravity Power Module)

[0007] A GPM uses a very large piston that is suspended in a deep, water-filled shaft, with sliding seals to prevent leakage around the piston and a return pipe connecting to a pump- turbine at ground level. The piston is comprised of reinforced rock and in some cases concrete for low cost. The shaft is filled with water once, at the start of operations, but is then sealed and no additional water is required. As the piston drops, it forces water down the storage shaft, up the return pipe and through the turbine, and spins a motor/generator to produce electricity. To store energy, grid power drives the motor/generator in reverse, spinning the pump to force water down the return pipe and into the shaft, lifting the piston. Hundreds of megawatt-hours per shaft can be stored with high efficiency, since pump- turbines have low losses and friction is negligible at modest piston speeds. Tackling the cost issue, economic operation of the GPM system depends heavily on the construction cost of the shaft, which is surprisingly low. This is because the GPM system will require less excavation per storage capacity than many existing pumped storage hydro facilities and because that excavation uses proven technology from the mining industry. A small footprint and unobtrusive operation allows installations to be constructed even in dense urban areas. Claimed advantages include: modularity; use of existing technology; environmental compatibility; flexible siting; fast permitting; rapid construction; low cost per megawatt-hour; long lifetime; high efficiency; and a short time from project start to revenue. One of the issues with this system is the fine tolerances of the seal system and the inherent operation and maintenance issues associated with low tolerances.

GRAVITY ENERGY STORAGE (GES)

[0008] The idea is that large weights are elevated to store energy (E=mgh) and lowered to generate electricity as shown in Figures 1A and IB. The energy stored can be significant. Raising 1 tonne lm requires 1000 x 9.8 x 1 = 9,800J. 1 KWh = 3.6 MJ, so storing lKWh will require 368 tonnes to be raised lm. Storing lMWh would require 18,400 tonnes to be raised 20m or in linear proportion a lower mass raised to a greater height. 3680 tonnes raised 100m would also store lMWh. Mechanical gravity storage is up to 90% efficient. Taking into account this efficiency and margin of error, for the purposes of this document, it is assumed that 20,000 tonnes will be needed to be raised 20m to store lMWh or a proportionate equivalent.

[0009] A 20mx20mx20m block of concrete is 8,000 m3 and concrete has a density of 2,500kg/m3, hence a 20m3 block will weigh 20,000 tonnes. Allowing for efficiency, elevating this concrete block 20m will store lMWh

[0010] If 450GWH of electricity is to be stored to enable Australia to source 100% of its energy from renewables, and if all that energy was stored by mechanical gravity storage, then this would require 90,000 blocks weighing 20,000 tonnes to be raised 100m. Clearly there is a need for a very low cost and energy efficient method of storing electricity that can be easily deployed in multiple locations.

[0011] GES provides a cost effective and energy efficient storage solution that is able to be scaled and can, in part, address the Australian energy storage requirements. A cost effective and energy efficient energy storage solution that enables matching of supply and demand will reduce the cost of power to business and consumers.

PROPOSED GRAVITY ENERGY STORAGE SYSTEMS

[0012] In recent years several gravity power technologies have been proposed. One example is Energy Vault https://energyvault.com/ which uses a six-arm crane to lift concrete blocks up and down a 33 -storey constructed tower, ARES shuttle-trains that draw electricity from the grid, which powers their individual axle-drive motors, as they transport a continuous flow of masses uphill against the force of gravity to an upper storage yard. Another example is Sink Float Solution http://sinkfloatsolutions.com/ which uses ocean gravitational energy storage by having large barges lifting heavy submerged weights. Another example is Energy Cache storage system which uses buckets on a line that picks up gravel at the bottom of a hill, and moves the gravel to the top of the hill; when the process is reversed the gravel moves back down the hill and powers a generator to produce energy. Yet another example is Gravitricity, which moves weights suspended in a mineshaft to generate electricity. A problem with the Gravitricity technology is that there is a potential for the vacuum seal of the mineshaft to fail. All these technologies could play roles in renewable energy storage.

EarthPump Store (EPS] System

[0013] The basic concept of EarthPump Store is shown in Figures 2 and 3. The technology uses large containers (1) filled with compacted earth materials (2), such as soil, coal dust, limestone powder and other waste materials, that could be shifted between higher (3) and lower (4) points of an opencast mine structure (5). The earth materials (2) for the storage device can be obtained locally by excavating opencast mines and limestone quarries. The containers (1) could be mounted on railway tracks (6) or sliders and pulled using cables and motor/generator. When the heavy containers (1) move down, they release potential energy (i.e. electricity generation) to the main grid system (7), as shown in Figure 3). During the charge phase, the containers (1) are moved upward to store energy supplied by photovoltaic or thermal solar power, or wind turbines, using power when not needed by the grid, storing the energy for later use as shown in Figure 2.

[0014] EarthPump Store can be used for a large-scale storage in conjunction with main grid systems. The technology is environment friendly and simple to construct. The estimate cost of EarthPump Store is about $50/kWh or lower depending on the depth of opencast mine.

The cost of PSH storage (without considering land cost) is about $200/kWh while the cost of battery storage is about $400/kWh.

[0015] Problems with laying rails in abandoned open cut mines will now be discussed. The EarthPump Store system described above involves laying rails in an open cut mine. Figures 4A and 4B show a hypothetical circular mine 200m deep with the walls inclined at 45% and the diameter at the top of the mine at 1km. The length of rail placed on the incline (8), would be approximately 282m, and the base of the mine would be circular with a diameter of 600m. The circumference at the bottom would be about 1.9 kms. If the rails were spaced at say 6m at the bottom to allow for construction, then approximately 300 rails could be laid. The effective height of the storage at 90% efficiency would be about 180m and the amount of energy stored in Joules in the installation would be 300 rails x 180m x 9.8 x mass on the rails (kgs) = 530,000 x mass (kgs) Joules = 530,000/3.6x10**6 x mass (kg) KWh = 0.147 KWh per kg of mass. If the mass of a carriage was 100 tonnes = 100,000 kgs, the energy stored would be 14,700 KWh, or 14.7 MWh.

[0016] The laying of the rails (6) is a major capital cost. Several observations may be made:

• The rails should be laid properly to run for more than 100 years.

• The use of explosives to cut in the rail tracks is almost certainly allowed being consistent with prior permitted use. Bulldozers can be used to cut a track down from the top and be winched up using the winches that will be used to raise the weights.

• The weights will rise and be lowered down slowly, reducing rail design requirements.

• The load on the rails can be distributed by using a number of smaller weights that are connected by wire rope separated by a few metres. This will reduce rail design requirements. Smaller weights are likely to be require less maintenance and be easier to maintain and replace. However, the weights should be designed to last for more than 100 years. One idea is to cast a concrete block on the rail platform. The bearings should not wear greatly as they are not travelling large distances. In this document, a “rope” includes a wire rope, a cable, a wire cable and a chain.

• In Figures 2 and 3, the suggestion is that rails can be placed on above ground supports. This might work in a mine with a spiral road going up the mine but it seems inherently cheaper to have the sleepers and rails laid on the ground.

• The use of explosives in mining may impact the surface of the mine and require deeper foundations, adding to expense.

[0017] It is an object of the present invention to overcome one or more of the above disadvantages, at least to an extent.

Description of Embodiments

[0018] Disclosed herein is a system for building and operating energy storage systems using gravity storage comprising of some or all of the following components: a. systems for selecting suitable locations that will require little or no work on the terrain to effectively and efficiently store energy using that terrain, b. systems for selecting suitable methods of, and devices for, efficiently and cost effectively storing energy by using gravity in that location, c. new devices for storing energy by using gravity systems suitable for the selected location to maximize the energy storage at that location within an acceptable cost and energy input constraint, d. methods for minimizing the cost and energy input of construction of a facility to store the energy whilst ensuring the facility has a long life, e. ways to design out or reduce maintenance of the facility and its components, f. methods to optimize the efficiency of storing energy over the life of an energy storage facility and/or a group of facilities, and g. methods to minimize the cost, energy input and optimize the efficiencies of new energy storage facilities to be constructed in the future

[0019] Disclosed is a new systematic approach to mechanical energy storage by using gravity to store energy by raising and lowering weights located on a suitable terrain that can be used with little or no work done on the terrain. Large amounts of energy may be stored at as low a cost as possible. The principles applied to do this include:

1. Systems to enable the efficient analysis of relevant factors to enable the fast and efficient finding of locations where the cost effective and efficient storage of energy is possible. There are millions of possible sites, and a systematic and automated way to efficiently and cost effectively locate suitable sites for efficient energy storage installation will be developed. Site selection criteria include a. Sites that allow large numbers of heavy weights to be suspended and/or stored in a particular installation. i. Heavy weights can be lifted by using multiple winch/generators to lift in parallel with or without load balancing, and using mechanical advantage to lift heavy weights with light ropes and small winch/generators (in this document, “winch/generator” includes a combined winch and generator in the same piece of equipment, and a separate winch and a separate generator working together to raise weights and generate energy when they are lowered) ii. In many arrangements, weights can be automatically connected and disconnected from winch/generators allowing a very large number of weights store energy, significantly increasing the energy storage of an installation b. The ability to lift the weights over large vertical distances. The effective lift difference is the lift distance less the height of the weight. Doubling the lift distance will more than double the effective lift distance because the height of the weight will remain the same c. Minimizing the need to perform site works by carefully selecting suitable sites d. Selecting sites that allow multiple storage forms at the one location reduce fixed costs per MWh stored, such as grid connection costs e. Selecting sites that have a suitable geology for the installation of equipment to suspend and/or the weights f. Selecting sites which have low cost of connection to the grid. This will be zero for existing wind and solar farms g. Site acquisition costs, which will be zero with existing mines, low on abandoned mines, low for existing solar and wind farms, and may be zero with water sites Minimizing the energy input and cost of the weights by a. safely and efficiently constructing heavy weights in situ b. utilizing local materials c. designing structures to be able to use low strength cast weights produced from local materials d. mass producing weights, usually in situ Designing the mass of the weight to be sufficiently large so that for weights permanently attached to a winch generator, the winch/generator will be storing energy at maximum capacity during the window of cheap energy prices. In the case of solar, this will be when the sun is shining. The winch/generator should be working at full capacity during this window to store as much energy as possible. The design constraints include the mass of the weight, the height lifted and the mechanical advantage. Automatically allowing weights to be connected to and disconnected from ropes attached to winch/generators to allow disconnected weights to be stored until they are needed. The control system will be required to operate a number of winch/generators to produce an energy output and an energy input acceptable to the grid operators.

This might require the installation of a small buffering battery. Minimizing the energy input and cost of safely constructing the installations to allow the weights to be lifted a. Energy input, cost and capacity of winch/generator - mass produced, reliable, field tested, low maintenance or a winch/generator can be assembled from commercially available components if the commercial winch/generators do not meet the required specifications b. Energy input, cost and capacity of rope - longevity, safe working radius, capacity, suitability to environment. The weights that can be supported on the weight will also depend on the geometry of the site. For example, on a terrain at 45 degrees, the tension on the rope will need to be resolved by trigonometry c. Energy input, cost of the coiling mechanism to preserve the life of the rope

6. Making the storage systems as energy efficient as possible optimizing data driven control systems for individual terrains. This includes optimizing the operation of a single generator/winch and optimizing the operation of the entire installation

7. Using the installations to generate electricity as well as storing it

8. Minimizing the energy losses and costs of operating energy storage installations. One such method is to design out, or minimize, maintenance costs

9. Utilizing Virtual Power Plant (VPP) technology to efficiently connect to an energy storage site to the grid and enable the efficient trading or selling of power on the electricity market. A VPP is a cloud-based distributed power plant that aggregates the capacities of heterogeneous distributed energy resources (DER) for the purposes of enhancing power generation, as well as trading or selling power on the electricity market.

[0020] There are multiple terrains that can store energy. There are three (3) terrains that are explicitly considered in this disclosure. These terrains are used as examples and the principles can be applied to other terrains. Such terrains include, but are not limited to: vertical mineshafts, open cut mines, cliffs over land and/or water, and installations in water.

1. Vertical mineshafts where the objective is to maximise the weight that can be suspended in a relatively small diameter hole. Abandoned vertical mine shafts can be used to store energy. There are typically a number of ventilation shafts in a large mine that will provide an opportunity to store and generate energy. An alternative is to drill vertical shafts at the location of existing solar or wind farms. Having local storage will enable the solar or wind farm to maintain a regular supply through the day without the need to upgrade the grid connection to cater for peak generation or supply corresponding to diurnal rhythms. The storage releases energy at times of reduced generation, for example the sun does not shine at night and generation capacity is reduced during cloudy weather, similarly wind generation is reduced due to meteorological conditions. The price of energy when there is lower energy generated by renewable resources will likely be sharply higher.

2. Cliffs, hill sides, open cut mines and other sloping terrain where the weights will be in contact with the terrain.

3. Installations in water, both in lakes, rivers and in the sea, where the gravity storage is achieved by a number of different configurations. Four are explicitly considered: a. Pulling submersible floats below the water surface - the buoyancy force is the weight of the displaced water which is g x volume displaced x 1 (density of water is 1 tonne per m3). There are two different situations: i. Close to shore in relatively shallow waters where large and unsightly rafts may not be aesthetically and / or politically acceptable, and ii. Deep waters, in many cases, further from shore where there would be no objection to seeing large rafts b. Large floating barges in both lakes, rivers and the sea which will raise and lower weights to store energy where this will be acceptable to the community, and c. A combination of a submerged pontoon pulling floats down and suspending weights from the submerged pontoon that can be raised and lowered. This combined approach has the benefit of taking the pontoon to a depth where there will be little impact from a storm on the device. In a storm, the turbulence is considerably reduced at 10m, very considerably reduced at 20m. The draft of a large ship like Queen Mary 2 or a large aircraft carrier is less than 15m, so submerging the pontoon to 15m will largely eliminate the risk of collision. Removing the pontoon from sight by submerging it may enable it to be located in places where visible pontoons would not be permitted. d. Using a small pontoon with a winch/generator on it to pull down a large submersible float to an anchor on the seabed of lakebed. The rope connection between the large submersible float and the anchor would use a significant number of pulleys to achieve mechanical advantage. The buoyancy of the small pontoon on which the winch/generator is situated would be greater than the downward force exerted by the rope. A low cost, low energy input submersible float with little or no equipment on board could be designed to withstand depths exceeding 500m.

The terms, “floats”, “barges” and “pontoons” are used interchangeably in this document. Variables Relating to the Location of Energy Storage Solutions

[0021] Location of the energy storage system must be carefully and systematically analyzed and prioritized as site selection is critical in the efficiency of the energy storage system. The systematic analysis involves analyzing all relevant information which includes geographic information, geological information, weather information, tide and current information, access, energy efficiencies, energy inputs, costs and revenue opportunities some of which are discussed below. The systematic analysis will become increasingly sophisticated over time with machine learning.

[0022] Selecting terrain which has the ability to store large amounts of energy. One determinant is the height that a weight can be raised. A weight raised 200m will store 4 times the energy of a weight raised 50m for the same installation energy expenditure and cost. Another determinant is the mass and number of weights that can be suspended. For example, very large numbers of weights could be suspended in a large open cut mine or along a cliff which has adequate foundation capacity at the top, capable of supporting significant weight.

[0023] Sea cliffs should be selected where not only is there a drop to sea level but a substantial sea depth. Dense weights will have almost the same energy storage capacity above and below water, as the weight of the displaced water will be small relative to the weight of the displaced volume of the weight.

[0024] The deeper the water, the greater the energy that can be stored. Large amounts of energy can be efficiently stored in the deep seas. 1000 tonnes of relative buoyancy (the mass of the weight less the weight of the displaced water) lowered lm below surface level releases the following energy:

1000 tonnes x 1000 kgs x 9.8 x 1 Joules = 9.8 x 10**6 Joules 1 KWh = 3.6 x 10**6 Joules. So, 1000 tonnes lowered lm releases 9.8/3.6 = 2.7 KWh. 1000 tonnes lowered 6000m released 2.7x6xl0**3 KWh = 16.2 MWh. [0025] Three 21,000 tonne barges could store about lGWh. The rope itself will store energy as it is raised and will generate energy as it is lowered. For reasons of calculation complexity, the energy storage contributed by the rope is not included in calculations in this document however is not insignificant in the scheme.

[0026] The Calypso Deep in the Ionian Sea in the Mediterranean may be one place close enough to shore. So might the Japan Trench. The Great Australian Bight gets to 6000m depth, however this is some distance from shore. There may be places on the Australian Eastern Seaboard where cable connection is possible, as the continental shelf only extends a few kms in some places.

[0027] Siting energy storage facilities close to low cost grid connections.

[0028] Situating energy storage close to solar or wind farms would enable energy generated by the solar/wind farms to be stored without the electricity being transmitted through the grid, allowing solar farms to sell power when the sun isn’t shining and similarly with wind farms to release power to the grid when the wind isn’t blowing. If the sun is not shining or the wind is not blowing, there is a reduction in supply, with an increase in energy prices. Storage enables energy to be stored when prices are low and sold when prices are high. The solar or wind farm connection to the grid is designed for peak power generated by the solar and/or wind farm. Stored power will be released to the grid via the same connection at times when the generation is less than capacity to maintain supply to the grid in response to demand. By enabling the solar/wind farm to release energy 24/7, energy storage will allow the wind/solar farm to maintain supply at lower but more constant levels without needing to upgrade the grid connection capacity because energy can be sold to the grid when the sun is not shining. However, storage will also allow the solar or wind farm to increase their generation and sales of solar and wind without increasing the grid connection. This capacity is enabled by storing the increased energy generated and releasing it during periods e.g. at night time, when there is capacity on the existing grid connection to absorb that additional energy.

[0029] By selecting locations where multiple forms of storage can use the same grid connection and share fixed installation costs. For example, preference sea cliff locations where energy storage using floats is also possible. This should enable the sea cliff storage and the storage in water to both use the same connection to the grid, saving costs. Similarly, siting a floating storage platform near a wind farm located in the ocean means that there can be sharing of installed electrical transmission capacity.

[0030] The cost of obtaining permission to install a mechanical energy storage device at that location are low or zero. Storage can be added to mines with little or no site acquisition costs. It appears from early research that there is no cost to “temporarily” moor energy storage devices in the sea which is not a harbour or used for navigation. The ability to have the storage solution inflate an additional bladder to lift the anchoring weight may be legally important, as this will reduce costs of relocating the storage device.

[0031] There will be fixed energy inputs and costs associated with each installation, so it is important to maximize the energy stored in each installation as the greater the energy, the lower the fixed cost per KWh stored. In the case of All Terrain Rollers (described in subsequent sections), energy stored can be increased by having more and heavier rollers suspended in a location, and by having rollers stored at the top of the mine ready to be used when there is calm or cloudy weather reducing wind and solar generation.

[0032] Criteria for selecting the location of the installation of float based energy storage systems should include information about tides, waves and the likelihood of storms, proximity to the land for the electricity connection, water depth (deeper water will provide more energy storage and more security during a storm event) and how far the floats will need to be floated to be put in place.

[0033] Preference should be given to sites which: a. Are sites allowing multiple forms of energy storage and/or generation b. are suitable for solar and wind installations. Energy generated from these captive solar and wind installations can be stored directly without passing the energy through the grid, improving system efficiency and placing less demand on the grid and can be sold at peak demand when electricity prices are highest. c. which are close to suitable, low cost connections to the energy grid d. have low site acquisition costs (e.g. low land prices) e. where damage to human life or property is eliminated if there is an accident because say a roller cable breaks. f. which have a geology to minimize the energy input and cost of anchoring the winches e.g. where the top of the mine or cliff has good foundations for weights and generators to minimize the energy input and cost of constructing the energy storage installation g. which have good access e.g. to the top of the mine or the cliff h. which are close to sources of sand and gravel and/or other materials to be used to create weights and/or structures i. in areas where mines are closing and where there is a demand for new jobs to be created j . where the installation can be progressively installed, so that revenue can be generated while the project is being constructed. In this way, the energy input and construction costs can be matched to progressive capital raising.

Brief Description of Drawings

[0034] Preferred embodiments of the present invention will now be described, by way of examples only, with reference to the accompanying drawings.

[0035] Figs 1A and IB show a schematic of a mechanical system to store and generate electrical energy.

[0036] Fig 2 shows a schematic side view of a means for storing electrical energy in an open cut mine.

[0037] Fig 3 shows the open cut mine and means for generating electrical energy of Fig 2. [0038] Fig 4A shows a schematic side view of the open cut mine of Fig 2. [0039] Fig 4B shows a schematic top view of the open cut mine of Fig 2.

[0040] Figs 5A and 5B show a schematic of a means for lifting a weight.

[0041] Fig 6 is intentionally left blank.

[0042] Fig 7 is a perspective view of a component for assembly of a weight.

[0043] Figs 8 A and 8B show a top view and a side view, respectively, of a weight.

[0044] Figs 9A and 9B show a top view and a side view, respectively, of a mineshaft with different sized weights located therein.

[0045] Figs 9C and 9D show a top view and a side view, respectively, of the mineshaft of Fig 9A, with winch/generators connected to the different sized weights.

[0046] Fig 10A shows a top view of a weight, according to a first stage.

[0047] Fig 10B shows the weight of Fig 10A assembled together with a second stage 2 weight.

[0048] Fig 11 shows a side view of the weight of Fig 10B.

[0049] Fig 12A shows a perspective view of a plurality of the weights shown in Fig 7, in an assembled form that are able to be raised and lowered independently of each other.

[0050] Fig 12B shows a top view of a component of the weight shown in Fig 12A.

[0051] Fig 12C and 12 D shows an arrangement whereby the suspended weight in 12B will self centre.

[0052] Fig 12E shows an example of forming the weight shown in Fig 12D.

[0053] Fig 13 shows a weight on low pressure wheels that can be raised up a slope to store energy and lowered down a slope to generate energy. [0054] Fig 14 shows another weight on tank tracks that can be raised up a slope to store energy and lowered down a slope to generate energy.

[0055] Fig 15 shows a roller for generating electrical energy on a slope.

[0056] Fig 16 shows a schematic for configuring multiple rollers of Fig 15 on a slope.

[0057] Fig 17 shows the multiple rollers of Fig 15 on a slope with a stopping mechanism.

[0058] Fig 18 shows a detailed view of the stopping mechanism of Fig 17.

[0059] Figs 19A and 19B show a top view and a side view, respectively, of a repositioning roller and a configuration of the repositioning roller.

[0060] Fig 20 shows a perspective view of the rollers of Fig 15 on a slope.

[0061] Fig 21 shows the roller of Fig 15 connected to another roller overcoming an obstacle.

[0062] Fig 22 shows an example means for an All-Terrain Roller.

[0063] Fig 23 A and Fig 23B show other example means for steering the roller of Fig 27.

[0064] Fig 24 shows an example roller of Fig 21 with a means for laying material.

[0065] Figs 25A and 25B show an example method of assembling a roller.

[0066] Figs 26A and 26B show an example method of assembling a roller.

[0067] Fig 27 shows a means of allowing a roller to be directly below another roller without the rope of the lower roller coming into contact with the rope of the upper roller.

[0068] Fig 28 shows a top view of casting a roller with less weight.

[0069] Fig 29 shows a perspective view of the roller of Fig 28.

[0070] Fig 30 shows the roller of Fig 15 being swivel cast. [0071] Fig 31 shows the roller of Fig 15 being removed from a swivel cast.

[0072] Fig 31 A shows a side view of the All-Terrain Roller in use.

[0073] Fig 32 shows a front view of the roller of Fig 15 in use.

[0074] Figs 33A and 33B show example forms of an anchor in a sea bed.

[0075] Figs 34A and 34B show a top view and a side view of a float and shows how the float can be used for long term energy storage.

[0076] Figs 35A to 35C show example embodiments of a float system to store and generate electrical energy.

[0077] Figs 36A and 36B show side and front views of a particular embodiment of the float system of Fig 35B.

[0078] Fig 37 shows an example embodiment of the float system to store and generate electrical energy.

[0079] Fig 38 shows a housing for the winch/generators, compressors and other equipment located on a float system to store and generate electrical energy.

[0080] Fig 39 shows an example embodiment of a float system to generate electrical energy using waves.

[0081] Fig 40 shows a top view of multiple float systems connected together.

[0082] Fig 41 shows a flow chart of a system to build optimized components of an electrical energy storage device.

Detailed Description

[0083] Disclosed herein is a method for manufacturing components of an energy storage device, the process comprising the steps of: collecting site data; analyzing the site data to determine one or more site locations for at least one electrical energy storage and/or generation solution; prioritizing the determined one or more site locations based on efficiency of generating energy at the determined one or more site locations using the at least one energy storage and/or generation solution; calculating optimized parameters for components in the at least one electrical energy storage and/or generation solution for the prioritized determined one or more site locations; and transmitting the calculated optimized parameters to a manufacturing unit for manufacture of the components in the electrical energy storage and/or generation solution for the prioritized determined site locations

[0084] Also disclosed herein is an energy storage system for an existing natural or man-made terrain including: one or more rollers that are configured to roller over obstacles, said one or more rollers suspended from at least one ligature, each of the rollers having a first end and a second end, the first and second ends separated by a cylindrical surface extending therebetween; an inclined surface upon which the roller moves; a device for moving the roller up the inclined surface, the device connected to the one or more rollers by a ligature; and a means for generating electrical energy when the roller moves down the inclined surface, wherein a pressure exerted by the roller on the inclined surface is less than a pressure that can be supported by the inclined surface.

[0085] Also disclosed herein is an energy storage system for a body of water, the energy storage system including: a first pontoon to float on the body of water; at least one means for generating electrical energy attached to the first pontoon; a second pontoon having a volume that is greater than a volume of the first pontoon, the second pontoon located adjacent to the first pontoon; an anchor located at the bottom of a sea or lake bed; and a pulley having one or more ligatures to connect the anchor, the means for generating electricity and the pontoons to each other so that a force exerted on the one or more ligatures is resisted by the anchor; wherein in use, the second pontoon is moved by the means for generating electrical energy from a stored position to an energy recovery position, the stored position being closer to the anchor than the energy recovery position, and when the second pontoon is released from the stored position, the buoyancy of the second pontoon moves the second pontoon to the energy recovery position thereby generating electrical energy by having the ligatures turn the means for generating electrical energy.

[0086] Also disclosed herein is an energy storage system for a body of water, the energy storage system including: a housing to float on the body of water or to be attached to a pontoon; at least one means for generating electrical energy contained within the housing; and at least one weight connected to the means for generating electrical energy by a ligature, wherein in a stored position, the at least one weight is located adjacent the housing, and wherein in an energy recovery position, the at least one weight is not adjacent the housing and allowed to sink toward a seabed of the body of water.

[0087] Also disclosed herein is a method of constructing heavy weights from locally sourced materials, the method comprising the steps of: mixing the materials with a binding agent to form fixed materials; casting or compressing the mixed materials into blocks shaped to fill a defined space; constructing an in situ multilayer frame in situ so that a weight of the blocks above another block do not exceed the compressive strength of the block; and inserting the blocks into the frame.

Mechanical Gravity Energy Storage Systems Common Engineering Issues

Multiple winch systems

[0088] Storage parameters and energy retrieval depends on (a) the capacity of winches/generators; and (b) the number of winches/generators. The amount of stored energy is the mass suspended x distance suspended x the gravitational constant.

[0089] The system can be amplified by the addition of winches and pulleys to create mechanical advantage to enable equal load distribution and the lifting of heavier weights. A schematic of the system 10 is shown in Figures 5 A and 5B.

[0090] Rope slings 12 and 13 allowing multiple winches (not shown) to equally lift a single large weight 14 with the same load by having 2 winches pulling either end of a rope with the weight suspended on a pulley (15) on the rope between the winches. This principle can be extended to 4 winches by having 2 winches pulling rope 1, 2 winches pulling rope 2, and pulleys on ropes 1 and 2 are connected by rope 3 on which a pulley is placed supporting the weight, as shown in Figure 5B.

[0091] The use of a single pulley with the right configuration can double the mass suspended for a given capacity of winch/generator. The equation used to calculate the force required to move the moving weight is F=Mass/(Mechanical Advantage). The greater the number of pairs of pulleys means greater weights stored for a given capacity of winch/generator, which can enable energy efficient, low cost, longer term storage and the ability to design a facility to match the needs of day to day storage and longer-term storage. Most of the pulleys will have limited usage as they would likely rise and fall a maximum once a day for short term storage. The frequency of raising and lowering will likely be less than daily if longer term storage is required. High-quality pulleys with long work life should be selected and additional suspension points should be incorporated on the weights to enable pulleys ropes to be replaced. [0092] Mechanical advantage can also be applied by using a suitable gearbox. The advantage of a gearbox is that it can reduce the length of rope needed to lift and lower a heavy weight. The gearbox may also allow a heavy weight to be raised slowly and released more quickly to generate energy at a higher power.

[0093] In an exemplary embodiment, the pulleys 15 will enable a 500 tonne winch to lift a 2500 tonne block by winding in 500m of cable to raise the block 100m (theoretical mechanical advantage of 500%). This may limit the speed that individual weights can store energy. However, this will enable multiple weights being available to store energy at the same time connected to the same cable and increase the total energy storage capacity. The strength of the wire rope may also increase the stiffness of the wire rope and large diameter pulleys may be required.

[0094] Rate of energy storage and generation will depend on the size of the engine/generator and the number of separate engine/generators. Multiple generators provide redundancy and can allow the storing and generating of electricity to be conducted in parallel in different winch/generators. This feature can simplify control systems in some situations where for example additional energy is being generated whilst the system is delivering energy to the grid.

[0095] The cost of, and energy input to create, rope increases with tensile strength. If rope 12 has tensile capacity To, 5 lengths of rope 12 may cost less than a single length of a rope with 5 x To. The selection of rope will be based on minimizing energy input and cost for example using longer smaller diameter rope in a multiple pully set up verses a single larger diameter, higher tensile capacity rope.

[0096] The energy input and the cost of generator/winches also rises with the capacity of the winch/generator. 5 smaller mass produced winch/generators may have a lower energy input and cost less than the energy input and cost of a large winch/generator with 5 times the capacity of the smaller winches.

[0097] The weight size and shape should be designed to maximize the weight lifted subject to external energy input and/or cost constraints which include as the energy input into, and cost of, the generator, rope and the weight itself and physical constraints such as the maximum safe rope tension and the maximum winch/generator load.

[0098] The size of beams 12’ and 12” shown in Figure 5A can be reduced by distributing the load on a structure across the beam 12’ and 12”. Figure 5A shows how loads can be distributed across beams 12’ and 12” using pulleys 15 and rope 12. The method can be used in 3 dimensions by, for example, using circular beams.

Installation issues

[0099] Installation engineering common for all types of mechanical gravity energy storage installations include:

1. Low cost grid connections need to be prioritised.

2. Control systems and data collection and analysis must be implemented in the energy storage system to allow efficient control and optimization of the system

3. A commercially available high capacity winch/generator should be selected that has appropriate capacity, is highly efficient, is reliable, does not require frequent maintenance, and is not too large and heavy. (A reference to a winch or generator also includes a reference to a winch/generator). Further consideration must be given to whether the winch is AC or DC, is single phase or 3 phase, the input and output voltage of the winch, and the systems required to connect the winch and generator to the grid.

4. Maintenance should be designed out of the system wherever possible (e.g. removing the need for divers in aquatic situations), and maintenance should be simplified by design, such as allowing winch/generators to be quickly and easily replaced and then repaired or maintained in a convenient place such as a workshop. Equipment that needs to be maintained should be safe and easy to access and be easy to maintain. Ropes and pulleys will be designed to be easy to replace. This may require that there is way of safely securing the weights, e.g. on a preinstalled static rope or having a place where a new static rope on a constructed structure can be easily and quickly installed for maintenance purposes. The weight will have additional suspension points if required to suspend the weight from static ropes or additional dynamic ropes. (In this document, the term “dynamic rope” is a rope connected to a winch/generator for raising and lowering weights. It is to be contrasted with a “static rope” which is used to attach to weights and hold them in position, usually at the top of a lift.) Once the weight is secured to the static rope, the tension of the dynamic rope can be relaxed, which can enable the dynamic rope to be conveniently changed. Another approach is to have the facilities in place to quickly and easily install a second dynamic rope which can then have the weight progressively transferred to the new rope. The minimum equipment should be on the weight itself. For example, if a weight needs a swivel, then the swivel should be attached to the rope, not the weight. If the weight is attached to a static rope, then the dynamic rope can be disconnected from the weight and the swivel changed. The same principle applies if a system of pulleys is being used for mechanical advantage. This should be attached to the dynamic rope, not the weight. In a mineshaft, the pulleys can be mounted on top of the support structure to increase the lift height and to make the pulleys easier to access. Where possible, industry standard equipment should be used that is field tested, reliable, low energy input and low cost and low maintenance.

5. The permanent engineering structures for storage installation should be designed for a minimum 100 year serviceable life.

6. Steel cables / wire ropes need to be selected based on the flexibility or stiffness of the cable. The more flexible the cable, the smaller diameter pulleys that can be used, potentially allowing more pulleys to be used in confined spaces. High load bearing cables can be expensive and can be stiff with large diameter pulleys required.

[0100] The installation can happen sequentially. Once the connection to the grid is in place, energy can be stored and generated whilst the facility is being constructed.

REPLACING WORN ROPES

[0101] Another engineering consideration is replacing worn ropes. There are several ways this can be undertaken:

1. Ropes and pulleys will be designed to be easily replaced. This may require a way of holding the weights safely, e.g. on a preinstalled static rope or having a place where a new static rope can be easily and quickly installed for maintenance purposes. The weight will have additional suspension points if required to suspend the weight from static ropes of additional dynamic ropes. Once the weight is secured to the static rope, the tension of the dynamic rope can be relaxed, which can enable the dynamic rope to be conveniently changed. Another approach is to have the facilities in place to quickly and easily install a second dynamic rope which can then have the weight progressively transferred to the new rope.

2. If a weight is suspended using 2 winches with the weight suspended on a pulley, then the weight can be lowered to the ground, and a new rope attached to the worn rope and pulled through the wheel and connected to the two winches. This means that the ropes can be safely replaced remotely from the weight.

3. The weight could be suspended by 3 ropes, any two will support the weight. One rope can be replaced and then the second and then the third.

4. The ropes can be replaced at the top of the lift using methods to securely hold the weight on fall prevention latches allowing a new rope to be attached and then the old rope replaced. For example, the weight could have a hole in it large enough for a sufficiently strong bar or beam to be pushed through the weight to support the weight while the rope is changed. Another way is for there to be two places to support the weight, each with sufficient capacity to hold the weight, allowing a new rope to be attached while the old rope supports the weight. When the new rope is attached, it can take the load before the old rope is released and detached from the weight.

The Design of Efficient and Safe-to-Install Weights

[0102] Minimizing the height of the weight is important where there is a short drop because the height of the weight will reduce the height that the weight can be lifted. This is increasingly important if the weights can only be lifted say 50m. A weight that is 10m tall can be lifted 40m but a weight that is 5m tall can be lifted 45m which is over 10% more efficient.

[0103] Weights in mine shafts need to be shaped in to fit into the mineshaft with a minimum clearance from the walls to maximize weight. Some weights may need to be balanced to some extent so they hang plumb and can be raised and lowered without hitting the walls of the shaft. A guide roller system can be introduced to the weights to enable them to travel freely in the mine shaft. [0104] Weights can be made of metal like weights in a gym that can be added to a central support. They can have a hole in the middle and they need to be slid over the central supporting rod, or they can have a slot cut in them to allow the weight to be slid onto other weights supported on the central supporting column. Aligning these slots can be used to balance the weight so that it falls vertically in all directions. Guides and clips can be used to ensure that the weights do not move relative to each other or to the supports used to suspend the weights.

[0105] Figure 7 shows weight 14” in another form where the weight 14” is cast so that they stack and behave like stackable blocks. A benefit of the connected weights shown in Figure 7 is that they can be put together quickly and safely. The weight 14” has at least one locating pin 18 and at least one receptacle 19 to align and receive the locating pin 18.

Casting weights in situ

[0106] One method is to use materials available at the energy storage site. Often this material may be waste, there is no further energy input other than transport, and will cost nothing and remove the cost and energy associated with the disposal of the material. The material can be mixed with a binding agent such as cement and compressed in a press to form a block or cast to make concrete blocks (with aggregate) or mortar blocks (without aggregate) (either of which can be referred to as cast weights) which can be loaded onto a supporting frame or used as a slurry to fill a formwork container to create the required weight.

[0107] Figures 8 A and 8B show a preferred solution to stacking weights by using a stackable block to make the formwork into which the casting material can be poured. The formwork is made up of horizontal sections made of rolled U section steel 20 with the U facing inwards, each arc of rolled U section has a central angle of 120 degrees. Welded to this U section are radial arms 21 and 22 that attach to a small circular U tube section 23 facing the outer U tube section 20. The three segments are welded together to form a circular frame 24. The inner section fits over the inner support column. The bottom of the section formwork has apertures or recesses 25 every 60 degrees, as shown in Figure 8A. The top has matching conical locating pins every 60 degrees (think Lego ®). The formwork is constructed by laying layer on top of layer like brickwork so that above and below a join in the formwork is a solid formwork section. [0108] The weight 14’ ’ ’ can be vertically balanced to hang plumb as it is being poured by adding dense materials to the lighter side. Another way to balance weights is to add a number of smaller weights to the weight to balance it e g. by adding the weights at the top of the weight.

[0109] Different materials will have different densities, energy input requirements and costs. The selection will depend on factors including energy input and energy efficiency, cost, availability, equipment needs to construct the weight, safety regulations and the need for density in the location.

Weights for mineshafts

[0110] The space in a mine shaft is limited, so the design of the weights is important to maximize the weight by having the weights made from dense materials, and the weights designed so that they fill the space in the shaft. In a mine shaft, one way to increase the energy stored is by maximizing the weight suspended. Heavy weights (Wl, W2, W3, W4) can be raised and lowered by using multiple winch/generators (WG) working together, and by using pulleys (block and tackle) to provide significant mechanical advantage. This is shown schematically in Figures 9A to 9D. The moveable part of the block and tackle should be attached to the weight, and the other fixed part constructed above the shaft to increase the height the weight can be lifted. One or more guide wheels attached or embedded in the weight may allow closer tolerances between the weight and the wall, allowing more weight to be suspended. The height of the weights should be minimized to maximize the suspension height. Minimizing height is very important in shafts where the suspension height is limited. The weights should also be designed so that the space in the shaft is efficiently filled by the weight or weights.

[0111] Depending on the shaft diameter and length, the maximum weight suspended may be achieved by using multiple weights, as this may conveniently allow more winch/generators to be used, and lower capacity winch/generators may be less expensive, together with pulleys and ropes. This may also increase the reliability of the installation as there are more generators and a degree of redundancy can be introduced to the energy storage and generation system. [0112] Preferably, the weight size is selected so that the weight or weights will not hit the wall of the shaft and/or other weights, especially in the case of a malfunction. The guide wheels mentioned above will assist preventing the weights from striking the wall of the shaft.

[0113] However, it may be more energy efficient and cost effective per unit of energy stored to use less dense weights that are significantly lower cost and more energy efficient than more expensive dense weights.

[0114] The optimal weight design in a short, circular mine shaft will probably be a single weight. In a larger shaft, 3 larger diameter circular weights could be used with 4 smaller circular diameter weights: one central weight and three weights between the larger diameter weights and the shaft wall. The smaller weights could be significantly longer that the larger diameter weights, and an advantage of this is that the pulley systems will be at different heights and orientation, and so less likely to interfere with one another, as shown in Figure 9. There is also advantage in the ability to match generation profile with demand as the weights can be lowered separately or a number in combination to release the optimum amount of power to generate electricity when electricity prices are high, thus generating the greatest income.

[0115] It is likely that there will be a small number of different standardized weight sizes used, allowing low cost, energy efficient mass production of the standardized weights, or the formwork for the weights if they are to be cast in situ.

[0116] The configuration of weights in a shaft will need to take into account tolerances in the dimensions of the weights, tolerances in the dimensions of the shaft and tolerances in the pulleys supporting the weights. Adding or embedding guide wheels operating in a vertical direction to the weights may reduce the tolerances and allow greater mass to be suspended. The guide wheels could fold at the top and bottom so that the maximum lift can be achieved and/or can be recessed into the weights.

[0117] Underground mines need multiple ventilation shafts. Many of these shafts are circular with diameters between 4m and 6m and can be in the order of 1000m deep. The weight(s) would be supported by a structure that sits above the mine shaft. Very heavy weights would likely require multiple winch/generators which can be sited around the shaft, on multiple levels if required, as shown in Figures 9A to 9D.

[0118] The arrangement in Figures 9C and 9D shows a substantially annulus shaped plate 26 around the top of the mine cavity 26’ with the winch/generators (WG1 to WG8) evenly spaced radially on the plate 26. The arrangement shown in Figure 9A allows the plate 26 to anchor the winch/generators without the need for expensive individual foundations for the winch/generators (WG) to be constructed.

Creating weights for mineshafts using materials in situ

[0119] One way to obtain very low cost and energy efficient in situ materials to create weights is to bore a mineshaft in to the rock substrate, and set up a plant next to the mineshaft to create concrete or mortar blocks mixing the borings with a binding agent such as cement and compressing them in a press or casting them. The blocks can be stacked up to form weights in the new mineshaft and in other abandoned mineshafts close by. The energy stored per mineshaft will not be maximised, but the total energy stored per KWh and per dollar invested (stored energy capital intensity) in the installation will likely be far higher. Where there are abandoned mineshafts close by that will need cast blocks for weights, the mineshaft diameter and depth to be bored can be varied to produce sufficient but not surplus materials for weights.

[0120] The concrete or mortar blocks will not need to be strong as the weight will have a structural supporting frame so that there is a floor every say 5m and the weights on the bottom of the floor will only need to support the weight of the cast blocks above. The intermediate floor spacing will be such that the cast blocks are not crushed by the mass above.

[0121] If there are several mines in close proximity, then boring new mineshafts close to each other and using the same concrete block on site manufacturing set up will further reduce energy inputs and costs through economies of scale. Having mines close together may enable all the energy storage systems to interconnect forming an integrated system providing the ability to supply at an optimal level to a single grid connection. The weights may be created or cast using locally sourced materials which may include crushed rock, sand, dirt, mine shaft drilling waste or other waste. In an embodiment, the locally sourced materials are dense materials.

Safely installing weights in mineshafts

[0122] The equipment at the top of the mineshaft is installed. This will include a load bearing structure above the mineshaft on which pulleys are mounted and winches which are anchored around the mineshaft. The height of the structure should be greater than the height of the stages of the weight to be constructed in the mineshaft in order to allow 360 degree access to the stage and the weight during construction. Where practical, pulleys and other devices to spread the load should be on top or outside the load bearing structure to allow space for construction and to maximize the height of the lift of the weight. However, space considerations at a site may require that pulley systems supplying mechanical advantage be attached directly to the weight in a mineshaft, (and on cliffs, on the slope for ATR’s and between the float and the weight for sea storage.)

[0123] In the top view of Figure 10A, construction on the weight 14 starts with a load bearing base plate (BP) that is attached to 4 ropes each spaced at 90 degrees radially at the circumference and indented slightly to ensure the ropes (R1 to R4) do not contact the mineshaft wall (not shown). The ropes (R1 to R4) are securely attached to the base plate BP using a suitable anchor known to those skilled in the art. Other geometries are also possible.

[0124] The Stage 1 frame is then put onto the base plate. Stage 1 is in four 90-degree parts. The side view of Figure 10B shows each 90=degree part having a base BP, a top (TP) and three vertical supports (S) - one at the centre and two on the circumference. The 4 sections labelled A, B, C and D in Figure 10A are put into place and bolted together. Suitably sized guide wheels are bolted to the uprights on the circumference to guide the ascension and descension of the weight. Guide wheels to guide the weight up and down the mineshaft can be installed in some or all of the stages.

[0125] Stage 1 is then filled with specifically cast cement blocks that cover the area of the frame. An example of the specifically cast cement blocks is shown in Figure 10A as circled numbers 1, 2 and 3. Successive layers of blocks are added until the first stage is filled with blocks. The vertical supports S can be grasped and used to help in the positioning of the weights.

[0126] Stage one is then lowered into the mine shaft until the top of stage 1 is at ground level. The lowering can be done by a winch or by a slowly released brake that can let the rope through slowly and then stop the release. The Stage 2 frame is then put on top of the stage 1 frame, bolted into place and the stage 2 frame is filled with concrete blocks. See figures 10 and 11.

[0127] Additional stages to the frame will be added until the desired weight is achieved. When this is reached the top of the frame is put into place and fixed by clamping down the 4 supporting ropes to the top of the frame so that the frame is always in compression.

[0128] The top of the weight when constructed will have suspension points that will be approximately 5 degrees offset from the wire ropes supporting the structure. This will allow for the replacement of the ropes. The facilities required to fit pulleys and generators at approximately 5 degrees offset will also be constructed during the construction phase. New ropes will be attached to the suspension points on the top of the frame, and then tensioned to take the weight. This will allow the tension in the original 4 ropes to be released.

[0129] An alternative is to have fixed ropes hanging from the structure at the top of the mineshaft. The weight is raised. The fixed ropes are then attached to the suspension points on the top of the weight frame. The weight is then slowly lowered using the old ropes until the weight is supported by the static ropes. The old ropes can be cut and pulled out. New ropes can then be threaded through the system and attached to the suspension points. When all the new ropes are attached to the suspension points, the weight can be raised, the static ropes can be removed, and the weight can be available to store and generate energy using new ropes.

[0130] Another alternative is to have a central fixing point on the top of the weight and a supporting rope can be attached to this central fixing point. The rope may be threaded through multiple pulleys in a pulley assembly to achieve mechanical advantage. The pulley assembly is connected to the central fixing point. The corresponding pulley assembly at the top of the mineshaft would be attached to a frame above the suspension point. [0131] A further alternative is not to bolt together the segments of the frame making up a horizontal stage of the frame. In this way, 4 independent weights could be created. Figure 12A shows the 4 independent weights 28, which when pushed together, form a cylindrical weight. Each weight 28 would be supported on 3 ropes constructed in the same way as a single weight made up of a frame filled with cement blocks. When the frame construction is completed, the ropes will be tensioned and tied off so that the frame is in compression. There can be a single suspension point chosen at the center of gravity to allow the weight to hang vertically, or multiple suspension points 29 that can each be attached to a rope 30 attached to a winch/generator. The suspended weight 27 can be actively balanced by measuring the force on the different ropes and adding weights to the ropes with less force until the force on each rope is equal. Alternatively, ropes could be attached to the suspension points 29 to form slings to which ropes can be attached. See Figure 12C These slings can be designed so that the weight falls vertically. The usual mode of operation will be lifting the weights together so that they will not move relative to each other, they will have guide wheels to allow relative movement. See Figure 12D.

[0132] The frames could also be bolted together horizontally but not connected vertically, with each stage being supported by 4 different ropes that are offset by approximately 10 degrees.

[0133] Weights can also be stored long term in a storage facility built around a mineshaft by raising the weight to the top, sliding beams underneath the weight, disconnecting the weight from the rope and sliding the weight from the centre of the mineshaft to a safe distance from the mineshaft where the weight can be supported on the ground or on foundations built on the ground. To generate energy, the weight is connected to the rope or ropes (or any form of ligature), slid into position over the mineshaft, and lowered to the base of the mineshaft. The rope is then released. Another weight is slid on beams over the mineshaft, the rope or ropes connected, and the second weight is lowered. The second weight can rest on the first weight at the bottom of the mineshaft, if the first weight is strong enough, or on a structure at the bottom of the mineshaft. One way of implementing this is to have the bottom weight with a smaller diameter that the second weight, which in turn has a smaller diameter than the third weight. The structure will hold the second weight on the outside of the weight, and the third weight on the outside of the third weight. To store energy, the rope or ropes are lowered and connected to the weight and then lifted to the top of the mineshaft. [0134] Other methods of preventing the weight 27 from touching the wall of a mineshaft include slightly reducing the diameter of the weight, shaping the weight so that the top and bottom of the weight are slightly smaller than the rest of the weight, using a self centering pulley system so that the weight hangs vertically, and installing larger guide wheels at the top and bottom of the weight. These larger wheels can be fitted with tyres that are inflated with sufficient air (or some other fluid) so that they will not dig into the mineshaft if the walls of the mineshaft are friable.

[0135] Large buildings with large carparks like shopping centres, hardware stores and the like have large roof areas on which solar panels can be placed. Energy storage systems can be sited in the carparks by boring holes in the carpark to suspend weights. The winch/generators can be situated underground so that the size of the carpark remains the same. Standard kits in containers may be produced for various different bore hole diameters and depths. The parts numbered and arranged in the container to minimize the complexity of assembly.

[0136] By situating the energy storage underground, it becomes possible to site storage devices in parks and other places where it would not be possible to build above ground storage devices. An example is the installation of an underground storage facility in a park bordering a substation. The site acquisition costs may be low or waived because of the benefits to the community of local power storage.

[0137] Technology to manage a local microgrid can also installed with the energy storage device enabling the connection of properties with solar panels and/or wind turbines to the storage device, and the connection of the storage device to the substation with minimal cost and energy expenditure to the substation.

[0138] Water may be encountered when boring mineshafts. The mineshaft can be sealed using chemical grouts that will cure in a water environment, or cladding can be attached to the wall of the mineshaft where there is an ingress of water. Expanding formwork can be used to hold the cladding in place while it is being attached. It might also be decided to allow the ingress of water and use the water if there is a shortage of water caused by drought for example. A container can be put on the top of the weight which can be filled with water and the water can be drained into a tank when the water container reaches the top mineshaft. The water can be used independently, or it can be used to store energy as described elsewhere in this document.

[0139] An additional way to store energy long term in mineshafts is to provide one winch/generator lifting weights in several adjacent mineshafts. The winch/generator would disconnect from one rope coil on mineshaft A, move on rails to the next rope coil connected to a weight in mineshaft B, connect with the mineshaft B rope coil and raise of lower the weight as needed.

A fast energy efficient low energy input and low-cost gravity energy storage solution for open cut mines and similar steep terrain

[0140] One aspect of this invention is to use natural terrain such as steep hills or cliffs, or man-made terrain such as open cut mines, for gravity storage using minimal site preparation and without the need for expensive infrastructure like rails as proposed in the EPS system.

[0141] One benefit of an open cut mine is that there are unlikely to be lengthy planning decisions to allow for the installation of energy storage systems in the mine, and heavy equipment and explosives are already in use in open cut mines and so can be used for earthwork for energy storage systems.

[0142] In the photograph of an open cut mine at http s : //www.ws set . cl es/d eep- storage. it can be seen that there are a large varieties of terrain within an open cut mine, with some very steep walls, which would make it difficult to lay rails lines. As explosives have likely been used, the exposed surface of the mine is likely to be disturbed and have a rough surface with variable compaction.

[0143] There are at multiple different ways that the energy storage potential of steep terrain can be harnessed. All use a weight (W) suspended by a rope from a winch/generator (W/G), shown in Figure 1, at the top of the terrain to release energy by lowering the weight and driving a generator (W/G), and raising the weight using a winch (W/G) powered by inexpensive / surplus electricity to store energy. The weight design can vary between installations and includes at least 3 designs: [0144] Figure 13 shows an embodiment with a wheeled weight 300 where a mass 301 such as a concrete block is supported by a number of wheels 302 and can be rolled up and down the terrain by a rope connected to a winch/generator (not shown). The size of the mass 301, and the size and width of the wheels 302 can be designed to limit pressure on the terrain to a level that can be supported. The clearance of the mass 301 can be designed to allow the wheeled mass 300 to roll over obstacles on the terrain. The wheels 302 can have a breaking mechanism (not shown) which will stop the wheels 302 rolling e g. if the suspending cable breaks. One kind of wheel that will reduce the impact on the terrain is to have the wheel as a large low pressure tyre at pressurized at approximately 30KPa. The weight of the wheeled weight is spread evenly over the tire contact area. As the contact area increases the pressure and hence damage to the terrain reduces. This will be less likely to damage local flora. The wheeled weight 300 and other rollers described herein may be sized to avoid expensive site works.

[0145] Figure 14 shows an embodiment of a roller 400 including a mass 401 which is supported on tank tracks 402. The size of the mass 401, and the size and width of the tank tracks 402, can be designed to create a pressure on the terrain that can be supported by the terrain. The clearance of the mass can be designed to allow the tank tracked mass to roll over obstacles on the terrain. The tank tracks 402 in the front and rear of the mass 401 may extend beyond the height of the mass to clear obstacles like roads in the open cut mine, and may resemble early WW 1 tanks designed to climb through trenches. The tank tracks 402 drive wheels 403 and can have a breaking mechanism (not shown) in the wheels 403 which will stop the tracks moving e g. if the suspending cable breaks.

[0146] Figure 15 shows an “All-Terrain Roller” (ATR) 500. This embodiment uses a roller 501 as the weight. It is simple, energy efficient and low-cost but it should only be used where there are no humans below as there is no simple braking mechanism in the case of a breaking of the cable suspending the ATR 500.

[0147] The ATR 500 shown in Figure 15 can be used to roll up and down the terrain, and can be designed to roll over existing obstacles, and with minimized impact on the terrain: the diameter, length and shape of the ATR 500 is optimized for each site so that the pressure exerted by the ATR 500 is less that the maximum pressure the terrain can sustain, limiting the roller from digging into the terrain. Larger and longer rollers 500 will have an increased surface area that will come into contact with the terrain. The weight of the roller 500 divided by the area of the roller 500 contacting the terrain gives the pressure exerted by the roller 500 on the terrain. Rollers that dig into the terrain are less efficient at storing energy than rollers that roll over the terrain without digging into the terrain. Over time, the rollers may compact the terrain on some sites and this compaction will enable the weight of the rollers to be increased and/or heavier rollers to be added to store additional energy

[0148] An alternative embodiment of the ATR is to have the rollers covered by a low pressure tyre 502 that will distribute the weight of the roller 500 over a much greater area than the hard roller would be in contact with, as shown in Figure 15.

[0149] In some mines there may be a need to remove significant physical obstacles for All- Terrain Rollers to roll up and down the terrain. This can most probably be done using explosives and or by using heavy earth moving equipment. The techniques will depend on the topography and the geology of the mine and on workplace rules and planning requirements. If large winches are installed at the top of the mine, then large bulldozers could descent vertically and be winched up. Where there are roads cut into the mine wall, the earth moving equipment could use the roads to gain access to the obstacles and work their way up from the bottom of the mine. However, another way to overcome obstacles like roads in mines is to increase the diameter of the rollers or chain a number of rollers together to overcome these obstacles. As discussed above, weights with tank tracks and shaped as shown in Figure 14 can also overcome obstacles like roads.

[0150] Figure 4A and 4B shows that fixed rails 6 require separation at the bottom of an open cut mine to allow sufficient space for construction of the rails. Geometrically this will result in a much larger separation at the top, limiting the area of the mine that can be effectively used to store weights. However, the All-Terrain Rollers 500 (and the wheeled and tank tracked rollers 300, 400) do not have this constraint. Rollers that are permanently connected to winches can be in the same vertical plane but at different heights. A control system will stop them colliding. This allows more rollers per unit length at the top of the mine to be added than rail lines, as shown in Figure 16.

[0151] Another embodiment of the invention allows for some weights to be raised to the top of the mine and then stored at the top of the mine indefinitely. A large number of weights could be stored at the top. As shown in Figure 17, the roller 500 can be used when there are cloudy days leading to reduced solar energy output. When the roller 500 is pulled into place, chocks 350 are pushed forward, or away from the roller 500, and depressed into the terrain surface, allowing the weight or roller 500 to pass over the chock 350. Figure 18 shows the chock 350 which springs up and locks into place to stop the roller 500 rolling backward. To lower the roller 500, the roller 500 is pulled forward and the chock 350 depresses, and the roller 500 rolls down the mine generating energy. It is envisaged that multiple chocks 350 may be required for each ATR 500. Further, although Figure 17 is referenced with ATR 500, it is envisaged that rollers 400 and 300 may be used instead.

[0152] To utilize all the stored energy, multiple ATR 500 will need to be rolled down the terrain. When an ATR 500 is at the bottom of the mine or slope, the rope connected to the ATR 500 and a generator (not shown) must be disconnected, pulled to the top, another ATR 500 connected and then rolled down the terrain. A control system will be utilised to optimise the successive deployment of rollers down the terrain and detachment. A similar requirement will be needed when the mine is storing energy.

[0153] Figure 19A shows a repositioning roller (RR) 550 that is wider than the usual ATR 500. The RR 550 has an axle 551 that is used to enable a rope 552 to be repositioned without the rope 552 contacting the ground. The RRs 550 have large wheels 553 at each end whose radius approximates the diameter of an ATR 500. The rope 552 is attached to the middle of the RRs 550 and the RR 550 is heavy enough to drag the rope 552, preferably a wired rope, to the bottom of the mine. At the bottom of the mine, a heavy roller is attached to the RR 550, and both the RR 550 and the ATR 500 are raised to store energy. At the top, the wheels 553 of the RR 550 are guided onto a ramp 570, shown more clearly in Figure 19B, that lifts the RR 550 above the narrower but heavier ATR 500 which does not engage the RR 550 ramp 570. The ATR 500 can then be rolled into a safe position where it can be disconnected from the RR 550. The RR 550 can then be lowered down the ramp 570 to bring up another ATR 500. The system is efficient as the energy used to raise the RR 550 will be similar to the energy generated by lowering the RR 550.

[0154] The RR system works in reverse to release energy. [0155] The rollers that are being stored at the top and the bottom of the mine may need to be connected by a straight road of compacted ground. As shown in Figure 20, several roads 580 can be created, but between the roads 580, additional rollers 500 can be permanently supported increasing the amount of stored energy.

[0156] The roller 500 will likely travel from the bottom of the mine to the top of the mine once a day. If the height of the mine is 200m and the angle 45%, the roller would travel about 280m. If the roller 500 has a diameter of 4m, the circumference is a little over 12m, the number of revolutions of the roller would be 280/12= 24 revolutions, so bearing wear will be low. Rope wear will also be low compared to chairlifts and other similar applications. Winch/generator wear should also be low as there will only be about 280 m winched per day.

[0157] Figure 21 shows how additional rollers 500 can be added to rollers 500 already suspended. One way this can be achieved is by pulling the roller 500 to the top of the mine and attaching an anchored fixed rope. Use the winch (W/G) to lower an additional roller 500 above the suspended roller 500 so that axles 503 of the suspended roller and the new roller can be connected by a connecting rod or rods 504. The winch is attached to the additional roller and winched to the top of the mine. The suspended roller is disconnected from the fixed line. Additional rollers can also be added at the bottom of the mine. Another way of doing this is to lower a roller 500 and then roll the roller 500 into place using winches or by using a bulldozer, for example. The final alignment can be done using winches if this is more convenient. When the new roller is in place, the roller can be connected by a bar or bars to the rollers already connected to the winch. Figure 21 also shows how two rollers connected together can use the weight on the upper roller to assist the lower roller move over an obstacle that could stop a single roller. Once the lower roller clears the obstacle, it will drag the upper roller over the obstacle.

[0158] Greater roller density on a terrain can be achieved if one roller configuration using one rope is directly above another roller configuration using a different rope. It is important that the ropes do not become tangled, so the lower rope is held above the top roller by a frame with rubber rollers as is shown in Figure 27. R1 supports a lower roller 500.

[0159] If the ground compacts, rolling the terrain with a lighter roller 500 and then an increasingly heavier roller 500 may selectively compact the terrain and form ruts which will act as guides for a roller to keep it in a predictable path. Being able to steer rollers in the beginning will help to keep these tracks straight.

[0160] Another way to steer a roller 500 is to have either side of the roller 500 attached to a different winch (W/G) and have the winches (W/G) pull the roller at different rates. In Figure 22, the winch on the left is connected to the roller 500 by roller 508, whilst the winch on the right is connected to the roller 500 by rope 507. Consider a stationary roller.

Activating the left winch will shorten rope 508 which will change the direction of the roller 500 so that it will roll towards the right.

[0161] If it is decided to roll the entire terrain, it is possible to do this with two parallel rollers 500 that are connected together by rods 504 and / or piston assemblies 504’ that can move the axis of rotation of the rollers 500, defined by the axle 503, out of parallel. This, combined with having the two rollers suspended by two winches (W/G) will enable the rollers to be steered horizontally to some extent, and follow a predetermined path, as shown in Figures 23 A and 23B.

[0162] In order to keep the rollers rolling on one predictable direction, a second smaller winch can be installed at the bottom of the mine to ensure that the roller rolls towards the winch at the bottom when the weight is being released.

[0163] A terrain treatment plan for an open cut mine could include covering parts of the terrain with a binding substance such as bitumen, for example, that can be rolled into the terrain by the rollers. Figure 24 shows one way to apply a surface like bitumen will be to have a bitumen reservoir 509 between two rollers 500.

[0164] A vibrating device (not shown) can be added to the rollers to assist compaction.

[0165] Treatment plans for steep hills will probably need to be less invasive to pass environmental reviews. Rolling over vegetation such as grass may damage the grass and compact the soil, which may reduce the future vegetation. Such a site may not be suitable for rolling with heavy rollers. However, some sites where there is little vegetation and soil erosion may benefit from soil compaction as this may slow the erosion. Constructing All-Terrain Rollers

[0166] The rollers 500 can be mass produced on site using various concrete casting techniques. If particularly dense rollers are required, a concrete using Ilmenite rather than sand could be used. However, this may be cost and energy input prohibitive compared to using locally sourced materials.

[0167] Figure 25A shows the construction of the roller 500. Smaller wheel sections 500’ are made and glued together. The roller 500 can be constructed by creating smaller rollers 500’ that can be cast flat, raised and then glued together and to the axle 503, which may be in the form of a central axis pipe. Figure 25B shows the assembled roller 500.

[0168] Smaller ATRs 500 can be joined at the axle 503 to create larger ATRs 500 and this allows the ATR 500 to be suspended by a single central bearing 503’. This is shown in Figure 26A and Figure 26B.

[0169] Local materials can be used to reduce transport and transport energy costs. For example, if the materials around the mine are hard and strong rock, then it is likely that the gravel used in the concrete can be sourced locally Boring a mineshaft close to the top of the mine could provide much of the materials needed to cast the All-Terrain Rollers 500 and the wheeled 300 or tracked rollers 400. However the material may not be very strong and it may be necessary to cast the ATR 500 in a solid structure like a steel pipe.

[0170] The transport of large diameter pipes may be expensive so it might be lower cost and lower energy input to weld the pipe on site from segments that are transported stacked on a truck. Radius curved metal plate that fits on the back of a truck and that form a segment of a circular pipe will be trucked to the site and then held in a jig and automatically welded into a circular metal pipe. Another container might be a pipe used as formwork for round concrete pillars. The formwork pipes can be spiral rolled on site to any dimensions.

[0171] Round cardboard cylinders 502’ or similar objects used to cast concrete pillars in buildings could be inserted into the mold to lower the volume of concrete in the roller 500, and hence the weight of the roller 500. The reduced volume of the roller 500 is a result of cavities being formed therein, said cavities allowing an insert component to be inserted and removed to vary the weight of the roller 500. See Figure 28.

[0172] The axle and the tubes to limit the weight of the ATR 500 can be slid in horizontally to the newly welded pipe. The jigs at either end would allow for the axle and the weight reduction tubes to be accurately located so that ATR rolls symmetrically and evenly. An end plate can be welded into the pipe. See Figure 28. Two end plates could be welded to the pipe if the pipe were to contain water as weight.

[0173] Swivel casting. The roller 500 can be cast vertically in a cylinder which has supports for the pipe that is the axle 503 of the wheel 500’ . The cylinder would form part of the ATR 500 when cast. One way that the rollers can be cast is described below. A plate 591 with holes for the axle and the weight reducing tubes would be welded on one end of the pipe.

The mold would swivel from the horizontal to the vertical. Jigs 590 accurately hold the axle and the tubes in place. Cement would be introduced into the pipe and vibrated to ensure that the pipe is filled without air voids. When set, the pipe would be returned to the horizontal position, and the jig holding it would release. The ATR would then have bearings attached to the axel and be rolled out of the construction facility to the top of the cliff or embankment. The ATR can be attached to one or more winch generators for immediate use or can be used as an energy storage ATR for future use. An expanding castable material can be used to fill the pipe such as the material used in concrete filled marine piles to make the wheel stronger. See Figure 29.

[0174] An alternative is to cast the wheel using strong castable material and use the pipe as a mold. The procedure is the same except that the pipe would be lined to stop adhesion by the castable material to the pipe and when returned to the horizontal, the casting pipe would open and the cast ATR would be rolled out. Alternatively, hydraulic rams connect with both ends of the axel and lift the axel out of the mold and put it on the ground next to the mold.

Bearings are attached and the roller is towed to the top of the inclination where it will be lowered or stored as above. See Figures 30 and 31. Figure 31 shows the roller 500 mounted to an upright stand which has a swivel holding the mold at the center.

[0175] A welded steel ATR could be filled with water as a weight. Maintenance and Safety

[0176] Where possible, maintenance should be designed out of the system. Rollers should be designed for long life but if a roller breaks, it should be left at the bottom of the mine and a new roller used to replace it. It should be possible in many mines to lower the rollers onto the base of the mine where the roller can no longer roll down. Once the roller is properly chocked, safe maintenance can take place. Maintenance at the top of the mine can also be implemented, but this is likely to mean that the winches are set back from the top of the mine to allow the rollers to be maintained on level or near level land. A pulley may be required at the top of the mine so that the rope is clear of the top of the mine. Maintenance at the top of the mine may increase the cost of installing the top of the mine pulley systems because the pulley may need to be raised to allow the roller to pass beneath it if this is required. See Figures 31A and 32.

[0177] Static ropes will be designed into the system so that rollers can be safely attached to a static rope, allowing the dynamic rope, pulleys, bearing etc to be replaced.

[0178] The rollers, bearings, pulleys etc used in the system should be designed for minimal maintenance and for 100 year longevity. As concrete dries it shrinks and without reinforcing cracks into blocks. Reinforcing in concrete is provided to manage shrinkage cracking. The rollers will travel slowly so they will not need to resist dynamic forces, the concrete may then be able to be cast with additional reinforcing that might be required if the roller was to be subjected to regular impacts. The grade of the concrete can be designed to reduce costs whilst still being engineered to last 100 years. The roller axels 503 will preferably be thick- walled pipe and the bearing connecting the roller to the rope should be designed for longevity.

[0179] Safety gear like brakes on the rope will be implemented as prudent and as required by health and safety regulations. All ropes will preferably be designed so that they can be locked in place.

Lower Energy Inputs higher Energy Efficiency and Lower Costs [0180] Lowered energy inputs and costs of the All-Terrain Roller 500 embodiment result from: a. Making the weight itself a roller that can roll down the terrain to release energy and be winched up the terrain to store energy without the need for major earthworks such as laying rails. b. The diameter of the roller can be determined to travel over obstacles - a 5m diameter when in motion will traverse many irregularities in the terrain surface. Using steerable rollers, the system can be programmed or utilise systems similar to auto drive technology to avoid obstacles like large rocks and trees on a steep hill, allowing more mass to be stored on a particular terrain c. Two rollers can be connected so that if a larger obstacle is encountered, the weight of the second roller will cause the first roller to rise up over the obstacle and then pull the second roller over the obstacle. Rollers chained together vertically will add additional energy storage to the facility. See figure 21. d. The weight of the roller and the surface area in contact with the terrain can be designed by varying the diameter and length of the roller, the number of rollers joined together in a vertical train, the steepness of the terrain, and the weight of each roller. The weight of large diameter rollers can be reduced by systematically placing large cardboard cylinders used for casting concrete supports in the mould when casting rollers to reduce the volume of concrete without compromising the strength of the roller. See Figure 26A and 26B. As the ground compacts with regular rolling, additional weight can be added to the rollers by filling the empty tubes in the rollers. e. Rolling the roller up and down the terrain will compact the terrain and over time, this may stabilize the terrain and allow additional and heavier rollers to be added. The compaction effect may be less noticeable on steep terrain as the resolution of forces dictates that the compaction component of force (perpendicular to the ground surface) will be less than the weight (vertical force) of the roller. f. Some energy may be lost initially in ground compaction, but this should reduce to a small amount over time and can be compensated for by lower operating cost and higher energy storage efficiency and by being able to have much more mass suspended. g. Each mine will have different geology and geologists and mining engineers will be able to provide information to be used in calculations to optimize energy storage potential by minimizing or eliminating earthworks (e g. some obstacles may need to be removed), and by the roller design and distribution for each particular mine. h. Additional information about the terrain can be gathered by rolling test rollers over the terrain and observing the effect of the test rollers on the terrain. i. This test rolling can be used to develop a plan to optimize the terrain for energy storage by optimizing the roller and developing a plan to treat the surface of the terrain.

Storing energy at sea or in lakes dams and/or rivers.

[0181] Another preferred embodiment relates to a system to store energy at sea or in lakes, dams and/or rivers utilize a large float, barge, raft, pontoon or platform (these words are used interchangeably in this document), a winch/generator, and a rope connected to the raft. There are three implementations of the systems described below in general terms. a. A submersible platform that is pulled down to store energy. The upward force is the weight of water that the float displaces. Larger volume floats will therefore create more lift and can store more energy. Energy is generated when the float is released and rises in the water. The winch/generator can be located on the platform, with the rope going down and around a pulley and returning to the platform, can be anchored on the seabed or located on shore. A benefit of having the winch/generator on the platform is that maintenance or replacement of the winch/generator is facilitated. Having the winch/generator on land connected by the rope to a pulley on an anchor at sea and then connected to the platform enables simple maintenance but there are likely to be few locations where the topography makes this possible at an affordable cost and an affordable energy input investment b. A floating platform from which weights can be lowered which may or may not be anchored to the seabed or the bottom of a dam, lake or river c. A submersible platform from which weights can be lowered which may or may not be anchored to the sea bed or the bottom of a dam, lake or river.

[0182] Having the winch/generator on the seabed will mean that it is held in a fixed and stable position and that it less likely to be damaged in a storm. However the waterproof housing may need to withstand greater pressures and there needs to be a mechanism to raise the winch/generator for maintenance. Another benefit of having the winch/generator on the seabed is that the winch/generator can submerge multiple floats, which can store long term energy, in a similar way to storing weights at the top of a cliff or open cut mine.

[0183] The marine environment is a hostile environment. Being able to maintain the float at sea level is a major benefit as is being able to pull the float to land for maintenance. Having a larger number of smaller, low cost, low energy input floats will reduce the risk that long-term energy storage will be impacted by climatic events or by accidents - such as a collision with a float. The housing for the winch/generator and the air compressor should be strong enough to safely withstand the deepest water to be encountered at a site. Attaching a buoy to the float will inform people that there is a submerged object below the buoy. The buoy can have a light attached and snorkel and an airpipe if required. The rope attaching the buoy to the float should be strong enough to raise the float or components of the float if there is a malfunction.

[0184] In order to pull the float down, an anchor weight is lowered to the seabed which has a wire rope or chain attached to an anchor point on the seabed which could be a drilled anchor on a stone seabed or a sufficiently large weight to anchor the float. (“Rope”, “chain” and “cable” can be used interchangeably in this document). A buoy with sufficient flotation will hold up the rope or chain used to pull down the float or floats when the floats are not connected to the chain. [0185] The weight can be independently laid by using a barge with a crane. A more energy efficient method is to use the float itself to position the heavy weight by attaching additional flotation to the float. The float volume of 10,000 m3 will displace 10 tonnes of water. A 12 tonne weight or anchor to rock on the seabed will hold the float in place. If additional inflatable bladders with 4000 m3 displacement are attached to the float, then the float will be able to suspend the 12000 tonne weight, allowing the weight and the float to be towed into position by a small vessel. When in position, the weight can be lowered and the additional bladders deflated. This means that the installation is “temporary” which may allow for low or zero cost siting fees, and allows the device to be taken back to a maintenance facility for maintenance rather than substantial maintenance happening at sea.

[0186] Casting a large weight of 10,000 tonnes on land and attaching this to a winch generator rope on a float generally requires expensive equipment. It is therefore better to have the weight composed of smaller weights which can be moved with equipment that is on most docks. This allows for a large weight to be incrementally placed on the seabed by small craft. If possible, the weight should be designed to maximize the benefits of the underwater environment e.g. by creating an artificial reef.

[0187] An embodiment of the system 600 is to cast a plurality of l-2m diameter concrete spheres or weights 601 that can be manipulated using suitable grapples on a small crane. This is shown in Figure 33B. The spherical shape allows a relatively low strength material to be used as deep sea weights as the water pressure at depth will be applied in every direction by the water. Another benefit of the spherical shape is that the placement of the spheres in a conical container 602 will mean that the weights 601 will self centre and pack in a dense configuration in the container 602 making it easier to load the spheres 601 into the container 602. Supports 603 attached to the conical structure 602 will enable the conical structure 602 to stand vertically if the plurality of weights 601 need to be lowered to the sea bed such as in an emergency. A different shape may be used for anchors to be lowered onto the seabed. Figure 34A shows two large floats 604 and a smaller float 602’ therebetween. The buoyancy of the small float 602’ may be designed using mechanical advantage to be greater than the force of a rope that will submerge the larger float.

[0188] The rope or chain is attached to a large float 604 that has a generator (W/G) located inside or on top of the float 604, as shown in Figure 35 A. One configuration may be to have a pipe 605 through the centre of the large float 604 to help stabilize the float 604 as it is winched down to the seabed. Another configuration is to have two floats 604 and 604’ as shown in Figure 35B attached together with a rope between the floats 604 and 604’. Yet another configuration is to have a rope attached at either end of a float 604 or floats, as shown in Figure 35C. A further configuration is to make the floats 604 from large dimension plastic pipes 604”, as shown in Figure 36A and 36B.

[0189] The stiffness of an object is its ability to withstand external pressure. The tensile strength of an object is its ability to withstand internal pressure. The external water pressure increases by 1 atmosphere about every 10m.

[0190] In a preferred embodiment, the main float is submerged by pulling the float down toward the seabed with ropes, but having the winch/generator being located on a second float that remains at the water surface. The main float is connected by a pulley system to the anchor that uses mechanical advantage to submerge the float, and the float on the surface has greater buoyancy than the downward force applied by the cable. It is envisaged that there may be 2 winches/generators on the float that remains at the water surface so that both floats can be moved below the water surface during adverse whether events and to avoid visual pollution.

[0191] Preferably, there is provided an energy storage system for a body of water, the energy storage system including: a first pontoon to float on the body of water; at least one means for generating electrical energy attached to the first pontoon; a second pontoon having a mass that is greater than a mass of the first pontoon, the second pontoon submerged in the body of water below or adjacent the first pontoon; an anchor located at the bottom of a sea or lake bed to prevent the system from moving away from a desired location; and a pulley having one or more ligatures to connect the anchor, the means for generating electricity and the second pontoon to each other; wherein in use the second pontoon is moved by the means for generating electrical energy from a stored position to an energy recovery position, the stored position being closer to the anchor than the energy recovery position, and when the second pontoon is released from the stored position, the buoyancy of the second pontoon moves the second pontoon to the energy recovery position thereby displacing water and generating electrical energy.

[0192] A force is exerted on the second pontoon that will submerge the second pontoon due to mechanical advantage provided by a pulley attached to the anchor. The mechanical advantage will enable the buoyancy of the second pontoon to exceed the force on the one or more ligature.

[0193] Yet another embodiment is to allow the second float to submerge so that is the float cannot be seen. This may allow the float to be positioned in places where a visible float would not be allowed. This may be achieved by having a second winch/generator attached to the anchor pull the second float down to the preferred depth.

[0194] Sensors can be placed inside floats to measure air pressure and/or to detect water indicating the presence of leaks.

[0195] Large floats that are wider than normal trucks may present transport problems. However, if these large floats are constructed by the seashore or on the shore of a lake (e g. in harbors), they can be floated into place if they are to be positioned in the sea or the lake.

[0196] Figure 37 shows a float 750 which has a means to generate electricity in the form of a winch and/or generator (W/G) attached to the float. The float 750 may be modular and have individual pipes 751 that are capped at both ends.

[0197] One solution to the transport problem is to have the floats 750 built in one location by the sea, such as in China or Vietnam where they can be loaded directly onto bulk carriers and unloaded directly into the sea on arrival. The floats 750 can be designed to be fully contained in a truss and made to stack securely one on top of another. The floats would be designed with suitable lifting points. Once in the water, the floats would be towed into a facility where the weights would be attached to the floats and the floats could then be towed into position. Alternatively, a number of floats can be connected together and towed into place directly from the place where they are constructed.

[0198] Incorporating a bow structure to the float to minimize water resistance when being towed into position will reduce transport costs and transport energy expenditure and the time taken to transport the float to its destination

[0199] One embodiment may be a large steel pipe with domes at each end. A 10m steel pipe 40m long with domes at each end will have a volume of approximately 3,668m3. Internal radial bracing can be added as in a plastic pipe, and can be welded in place inside the pipe to provide bracing against both internal and external pressure. The radial braces will be strengthened by bracing the braces by running braces along the length of the pipe which will stop the radial braces from buckling in the longitudinal direction. In place of, or in addition to, external circumferential bracing rings can be added, which may or may not be in the same place as the bracing. Longitudinal bracing can also be provided. The wall thickness will also be designed for particular sites, with larger wall thicknesses and/or additional bracing used for deeper applications. These pipes can have a beam welded to the base of the pipe for ballast. Beams can be welded onto the top and bottom of the pipe can be welded onto the pipe or onto the external bracing rings. These beams can join the pipes together and provide towing and/or lifting points for winch/generators and large weights. A one way valve will be provided so that the pipes can be pressurized to test they are waterproof and to provide pressure to offset the external pressure of water when the pipes are submerged. These pipes can also be used to transfer gas that is produced at sea on a floating factory to land. Floating factories are described below. These pipes would be welded at the seaside using robotic manufacture. They would be constructed on rails that submerge into the sea so that when the pipes are completed, they are rolled into the sea where they will float and be towed into position.

[0200] Passive ballast weight can be attached to the floats to keep them level when being towed into position and being pulled towards the sea floor if permanent sea anchors are being used, which means a weight will not be transported with the float.

[0201] Also shown in Figure 37 is an electricity cable 752 is attached to the winch/generator (W/G) in or on the float and connects to land or the nearest substation in the case of the energy storage device being located in proximity to off shore energy generation installations such as wind farms. The electricity cable 752 will probably be weighted to the seabed by small weights. The electricity 752 cable can be installed last. This cable should be designed to transmit data as well as energy.

[0202] The float 750 or floats can be floated into position after the weight is laid or the floats or floats can be able to support the weight if additional temporary lift is provided e g. by using a bladder that can be deflated.

[0203] The air compressor can be connected to a snorkel to be able to compress air underwater, or the tank could be made sufficiently large that the air compression be done on the surface. Having an air compressor on the float also allows for dynamic ballasting of the float by having forward and aft tanks that can be filled with water or air as required. The air compressor and the generator/winch will need to be held in a closed, airtight and watertight container on the float. As they are working, they will generate heat that needs to be dissipated. It is likely that some form of water cooling may be required.

[0204] An alternative embodiment is to have a strong container housing the generator/winch and the compressor. In addition to mechanical bracing, such as circumferential bracing, this container is attached to a high pressure air tank that will allow the container and the air tanks in the pontoon to maintain pressure. Air can be compressed and pumped into the high pressure air tank when the pontoon is on the surface or via a snorkel when submerged. Maintaining the winch/generator and the compressor can be achieved by access via a hatch at the top of the container or by opening the hemispheres at either end and pulling the winch/generator and air compressor out on the provided rails. A platform should be provided to make maintenance safe and convenient. A hatch over the rope coil can be opened to allow the winch axel to be disconnected from the rope coil. The structure should be designed to make it easy to replace the generator/winch and the compressor if required. It should also be easy to release the rope from the rope coil enabling the assembly to be replaced with another assembly and have the original assembly floated back to base for repairs.

[0205] One embodiment of a system to house the winch/generator and other equipment 800 is shown in Figure 38. It shows a main housing 801, a housing 80 for two winch/generators 802 and 802’, a compressor 803, and an optional high pressure air storage tank can be attached. The housing 801 is made of steel or some other sufficiently strong material (e g. carbon fibre) such that it will be able to withstand submersion to the depth of water at that site. Thinner material can be used if the housing is braced with reinforcing. The system 800 has a waterproof hatch 804 that allows for human entry at sea when the housing 801, 80 is above sea level. A fixed or rope ladder 805 for human ingress and egress can be provided. The housing 801 may carry ballast to ensure that it does not capsize. The housing 801 can be made sufficiently large to allow a human to stand inside, with or without a level floor made of mesh, and a ladder 805. Two fixing points are provided to allow the housing to be easily lifted by a crane. There is a one way valve 806 and a pump at the bottom of the housing that will allow water to be expelled. Apart from this opening, all the other openings will be at the top of the housing. These openings include openings for the connection to a snorkel 807, to the electricity supply, and for a cooling system to access an external heat exchanger 808, if this is required. An emergency battery 809, control systems 810 and a switchboard 811 are located as high as conveniently possible in the housing 801 to minimize the likelihood of water entering the container. Rope coils 812 are mounted on rails 813 on either end of the housing 801. The rope / ligature coil 812 has an axel 814. The axel 814 is disconnected, the housing 80G supporting the coil 812 is unbolted from the main housing 801 and the rope coil 812 is pulled out on 3 or 4 rails 813 - two on the base and one or two at the top above the lower rails. Three rails are designed to allow greater access to the main housing without operators hitting their head. However, if the main housing 801 is large enough (e.g. approx 2m) then 4 rails can be used. The top rails are shorter than the lower rails. Once the stops are removed from the top rails, the rope coil can be slid beyond the upper rails and conveniently lifted off. The rope coil housing 80G is attached on a flange that is bigger than the main housing 801, so that when the rope coil 812 is slid back, the end of the main housing 801 can be unbolted and opened. The winch/generator 802 and 802’and the compressor 803 are also on rails 813 and once released, can be slid out so that they can be worked on outside of the housing 80 G or replaced. They can also be worked on in situ.

[0206] The winch/generators 802, 802’ can each be housed in their own waterproof container 80 G that is built strongly enough to resist the submersion pressures that could be encountered at that site. These containers would be designed so that it is easy to replace them by unscrewing some bolts, sliding the winch/generator 802, 802’ on rails 813 to disconnect it from the rope coil, and lifting them using conveniently located lifting points. A self centering cradle enables the new winch generator to be conveniently lowered into position. Fasteners such as bolts, rivets or the like are tightened to hold the winch in place and the winch/generator is slid back into contact with the rope coil. The containers will likely need a cooling system that will dissipate the heat from the winch/generator into the sea.

[0207] The system 800 can be designed to have a low wind, wave and tide profile.

[0208] The system 800 can also be designed from smaller components which can be connected together in such a way that they can move independently (within a certain range) to lower the stresses on the raft in rough weather. Once underwater where there is little turbulence, the structure could be made rigid by tightening cables.

[0209] A further embodiment is to construct the system 800 above but allow the system to submerge to 20-30m to avoid storms. This may be achieved by having a second rope attached to the anchor and to a second winch/generator on the raft. Weights can be raised or lowered from the raft when on the surface or submerged. One way to allow the system to submerge will be to make parts of the housing 801 airtight and use ballast tanks to submerge the housing 801 and expel water from the ballast tanks using compressed air. In places where people do not want to see the weight, or in rough waters, submerging the system could be the usual operation. The housing 801 may be attached to a pontoon (not shown in Fig 38) to allow the housing 801 to float on the body of water. It is envisaged that the housing 801 and pontoon may be submerged as required.

[0210] If a storm is forecast, the submersible floats can be floated back to land where the float can be lashed down. The float could also be sunk - filled with water for the duration of the storm and then refloated by using the compressed air.

Creating sea weights

[0211] A problem is that it is possible to cast a single 10,000 tonne weight on land but conveniently, safely, energy efficiently and cost effectively moving and attaching the weight underneath a float will require custom developed equipment. A second problem is the strength of the weight, especially if low quality materials are used. A third problem is that weights may need to withstand considerable pressure if they are lowered to low points in the ocean. [0212] If there are installations in deep waters such as for the Ionian Sea, then mineshafts can be bored in suitable geology close to the water to create cement blocks to be stacked in a frame for lowering to 6000m. The weights will need to withstand the water pressure at 6000m. The weights and the frame holding the weights will need to be made of materials that will not corrode in salt water. The shape of the frame will be different from the long narrow frames used in mine shafts - the submersible frame needs to be shallow so that it can be easily stacked close to shore by a crane barge. Having a circular frame on a swivel will mean that the frame can be turned to be loaded with concrete blocks without the crane barge having to move. Weights will need to be inserted to minimize the tilting of the frame.

[0213] One implementation of the sea weights is to cast the sea weights as spheres (which are an inherently strong shape). They can be moved using a crane that has grapples designed for holding spheres. The weights that will hang in the sea can be placed in a frame that is designed to allow the weights to self centre when placed in the frame. Legs can be put onto the frame to keep the frame vertical if the frame is released to the floor bed, e.g. in an emergency. See Figures 33A/33B. Anchor weights which are designed to sit on the seabed are shown in Figure 34A/34B with a large surface area to provide the capacity to withstand horizontal as well as vertical forces.

[0214] Consider the following example:

[0215] Volume of a sphere 4/3 x pi x r3

[0216] A 2m diameter, lm radius sphere has a volume of 4.2m3

[0217] Assuming the same density as concrete, the weight will be 4.2 x 2.5 = 10.5 tonnes

[0218] Approximately 100 cement spheres will be needed to create a 10,000 tonne mass.

[0219] Both the sea weights and the anchor weights can be fitted with hinged tops that will stop the weights falling out. The tops can be counterbalanced so that they will stay open during loading. When the top is closed, the top can be held in place by a ring lowered over the part of the top that connects with the central support of the container. See Figure 33A/33B. Mooring the Rafts

[0220] Mooring the system 800 can be achieved by using traditional anchoring methods and connecting the system 800 to the anchor by a suitable chain or rope. Anchoring methods include a fixed anchor point on the seabed as shown in Figure 33 A, or a large weight that will enable the float to be submerged. The system 800 will be able to sustain the weight of the chain or rope. Having a winch/generator for the anchor will enable the generation of electricity from waves and tides. Currents and tidal flows can also be harnessed for energy generation by attaching turbines to the float to generate electricity. Anchoring the float in two places (e.g. fore and aft) so that it faces into the flow of the current or tide flow will mean that the turbine can attached in one position without the need to change the position of the turbine.

[0221] Having the system 800 tightly moored to a heavy weight on the sea floor will mean that the float can be cited close to wind turbines at sea without the raft hitting the turbine. Multiple anchors may be required for anchoring redundancy. It will be prudent to have the floats on the downstream side of any ocean current, and moored using two or more anchor to secure the float. Multiple anchors could be connected to different parts of the float to form a cable truss for added stability and security. The foundations of the wind turbines may be suitable anchorage points.

[0222] Multiple anchors will allow for the orientation of the raft to be fixed. This will be useful in maximizing the energy generation potential from ocean currents and tides of turbines placed on the rafts that have a fixed direction. This will not be required if the turbines can rotate to face into the current or tide. Alternatively, a system of using vanes to orient the raft with the prevailing current will maximise the energy captured form currents.

[0223] Joining multiple systems 800 together into a large hub that is anchored will reduce the anchoring and associated energy costs of each system 800.

[0224] Mooring a submersible float by creating a permanent fixing e.g. to rock in the seabed, or to a fixing drilled into the seabed as shown in Figure 33A, may provide a very low cost and energy efficient method of anchoring the float as no anchor weights will be needed so the cost of the energy storage system will likely be very low with high energy efficiency and low energy input.

[0225] If the raft was not permanently anchored to the sea floor, the suspended weights will also act as sea anchors and the shape of the weights and the raft need to be designed to take into account forces that will be applied when the surface current or wind changes in relation to the current at deeper levels where the weights are.

[0226] Anchors in sea or lake beds can be bored and an anchor can be cast into the bored hole. The bored hole may be straight or the base of the hole can be expanded as seen in Figure 33A.

Long term storage of energy underwater

[0227] It is possible to store energy by attaching submerged storage floats to anchors. The storage float is attached to a submerged anchor point by a static rope. The storage float is made of two floats joined in such a way as to allow a smaller winch/generator float containing a winch/generator and rope to go between the two floats of the storage float by having the beams joining the two parts of the storage float below the draft of the winch/generator float. The circular beam is attached to the front and back of both parts of the storage float. The pulley system to connect with the anchor will fit through the circular beam but the top part of the pulley system to connect to the storage float will not fit through the circular beam. The lower pulley connects to the anchor by a catch mechanism. When the rope is connected, the storage float is winched down to store energy. When it is at the bottom, a static rope catches the anchor and the dynamic is detached from the anchor and raised. Power would be provided by a cable that would be attached to the anchor and to a float at the surface for ease of location and connection. See Figure 34A

[0228] Once the storage float is connected by a static line, the winch/generator float will slowly release the tension on the rope, and will generate energy as the winch/generator float rises. Energy will be used raising the rope, but this will be offset in large part by releasing the cable when the storage float is to be released to the surface to generate energy. [0229] One catch mechanism is to have the anchor point being a large horizontal circle that is above the seabed. The catch mechanism 650 is a rod 651 with levers 652 that can move between an open position and a closed position to engage and close to disengage with the seabed, as shown in Figure 34B.

[0230] Energy is generated by the winch/generator float lowering the smaller pulley system through the circular beam to enable the catch system on the smaller pulley system to connect with the anchor in the seabed. The winch/generator winches down the large float to enable the catch mechanism on the static line to disengage and then the generator allows the large float to rise, generating electricity as it rises. the floats to generate electricity

[0231] As the storage system 800 is connected to the grid to store energy, adding electricity generation capability to the float is a marginal cost and marginal energy expenditure

[0232] Tidal flows, ocean currents and river flows can all be used to generate electricity.

[0233] Turbines that can generate electricity from flowing water can be added to the float based storage system 800 where the storage system in placed in a region where there are ocean currents, flowing rivers deep enough for effective energy storage and/or tidal motion. This is a marginal cost and marginal energy expenditure as the connection to the shore will have been justified by the storing of energy. Energy output from the turbine can be stored by the energy storage system. The turbines (not shown) can be on pads or swivels so that they face into the current. This can be achieved by using a vane to turn the turbine into the flow, or by using an engine to rotate the turbine. These turbines can be attached to the float or suspended above, below, in front, behind or along side the float which can be submerged or on the surface. These attachments can be fixed or can be moved independently of the float so that the turbines can be positioned in the location with the best potential to generate electricity. Data will be captured about the water flows, times, heights, directions and so on allowing systems to predict and optimized the energy being generated by the water flows. As the height of the float can be adjusted by the anchor chain winch/generator, it is possible to locate the best height for the turbine to be positioned to maximize the generation of electricity. [0234] If the storage system 800 is floating on the surface, the difference in tide height between low and high tide and the height of waves will provide additional electricity generation capacity according to the formula (displacement of the float in m3- weight of the float in tonnes) x gravitational constant x tide height or wave height in m. 368 tonnes raised lm requires lKWh. A float with volume 368m3 will displace 368 tonnes of water, so a wave lifting a 368m3 float lm can generate lKWh. If the wave frequency is 50 waves per hour, then the energy that can be theoretically generated will be 50KWh per hour.

[0235] It is possible to increase the generation capacity of a float by changing the ratio of the weights used to store energy and the weights used to anchor the float. If less weight is used to store energy, then the generating capacity of the float will increase.

[0236] Figure 39 shows a series of specially designed system 900 of electricity generating wave floats 901 (“wave floats”) attached to a platform 902 which is submerged to a few metres deeper than the wave height, or alternatively to the sea bed. This depth could be varied depending on wave height. The floats 901 would be attached to suitably sized generators 903 on the platform 902 and when a wave crest 950 passes the float 901, the wave floats 901 rise and in turn pull on rope 904 which is attached to the generator 903, thereby generating electricity. When a trough 951 approaches, the rope 904 will slacken and be reeled in by the winch/generator 903. The wave floats 901 are designed to be smaller than the distance between the crests (CD) of the waves to maximize the rise and fall of the floats 901 between the waves. The wave floats 901 should be shaped to minimize lateral motion of the float relative to the platform 902 to maximize the rise and fall of the wave float 901. Static ropes 905 hold the wave floats 901 in position to reduce the lateral motion of the wave float 901 relative to the platform 902 to maximize the vertical motion of the float 901 by stopping the winch rope moving radially.

[0237] In order to maximize the wave generation capacity, a large system 900, as shown in Figure 40, can be constructed of a number of floats 901 that are contained in a frame 910 that is made up of floating trusses 911 joined together in an external square, ring or other shape, which forms part of the frame 910. This increased area allows more wave floats to be installed on the platform. The large installation can be securely anchored in a fixed horizontal orientation with 2, 3 or 4 anchors, depending on the design, saving the cost and energy expenditure of anchoring each element of the installation. [0238] A float with 3 winch/generators can have two winch/generators storing or generating energy and the third winch/generator, the anchor winch/generator, can act independently generating electricity. If the two winch/generators are generating electricity by lowering weights, they will be able to generate less electricity when the anchor winch/generator is generating electricity and they will be able to store more electricity if the winch/generators are storing electricity.

[0239] An additional way to generate electricity using the float is to have a flat deck on the float with a flexible bladder containing air on the surface of the deck. As a wave rolls over the deck of the float, the flexible bladder will be compressed by the weight of the wave, and the air in the bladder will be compressed, which can drive a turbine to generate electricity which can be stored in the device itself using gravity.

Generating Energy using PY Panels

[0240] An additional way to generate electricity using the float 800 is to use the float 800 to support PV or solar panels above the sea to generate electricity. Being close to water will reduce the temperature of the panels, making them more efficient. The energy generated can be stored on the float by raising weights. The float can be moored front and back in the direction that will maximize the solar energy generation by the panels. If the float is submerged, the platform will be more stable and the positioning of the solar panels towards the sun can be done more accurately. If the anchor ropes are attached to moveable mooring points, then the orientation of the float can be moved to optimize the positioning of the solar panels towards the sun. This can allow the solar panels to track the movement of the sun. In a storm, mooring lines can be let out so that the float will face into the wind and the solar panels will present their edge to the wind. Mechanisms can be added to the float to allow the solar panels to lie flat or stand vertically in a storm. The float can also be designed to have the solar panels in a waterproof structure with a waterproof roof that is open when there is sunlight and closed when there is a storm. Sensors, such as a calibrated infrared sensor may be necessary to automate the opening and closing of the roof. This waterproof enclosure will enable the float to submerge in a storm to a depth where there is little turbulence without harming the solar panels. Alternatively, solar panels that are specifically designed to be submerged can be selected. [0241] An alternative or additional way to generate solar energy is to surround the platform with floating solar cells printed on a substance like plastic. Printed solar are currently being produced b the lifetime of the printed sheets is low but new materials to solve this problem are being developed. Floating these printed solar cells can be achieved by sticking a buoyant material like bubble wrap below the solar cell. Floating the solar cells on freshwater lakes will reduce evaporation which can be several metres per year in hot dry place like Australia. The floating solar cells can be held in place between moored energy storage floats or by small anchored buoys.

Other possible installations

[0242] Large floating wind turbines are increasingly being used in windy places like the North Sea. A large pontoon with suspended weight could be incorporated into the design of the floating wind turbine to enable it to both generate and store energy in the one facility. Alternatively, separate moorings for energy storage floats can be fixed into place when the anchoring points for the wind turbine are created on the sea floor.

Using stored energy off grid

[0243] In Australia, for example, there are many high cliffs that extend into the water for energy storage, there is access to seawater for electrolysis, land prices are low, there is good solar access and strong prevailing winds at select locations, there is also access to roads and/or railways. An off-grid factory making high value chemicals such as clean hydrogen, clean ammonia and/or ammonium nitrate which requires a constant supply of electricity, could be sited in these of locations. A key component will be energy storage as the factory will need reliable electricity regardless of whether the sun is shining, or the wind is blowing. One area that might have suitable locations is along the Nullarbor, for example. Other possible locations are open cut mines which have good access to road or rail infrastructure to enable the mined materials to be removed.

[0244] A floating pontoon can also be used as a platform for other activities such as fish farming. Fish farming in the oceans is seen as more environmentally friendly as fish excreta is usually dispersed by currents and does not fall to the seabed. Nets can be strung between floats to contain fish. More rigid cages with or without a roof can be constructed between floats or between the main float and specially constructed fish cage floats, or using specifically designed fish cage floats. Cages can be also attached to the weights used to store energy, allowing the cages to be raised and lowered using the same winch as the weight.

Food for some species of fish could be grown at sea, e.g. by fertilizing the ocean with iron ore, which is plentiful in parts of Western and South Australia. Insects could also be grown and turned into fish food The waste from harvested fish could also be used as food. If there is a regular transportation of products from a sea factory to shore, the energy inputs and costs of setting up and running a fish farm around the factory will be marginal.

[0245] Seaweed farming is also possible by constructing a floating raft on which seaweed can grow. In addition, a float could be used to support large clear glass or plastic containers containing bacteria or some other photosynthetic living organisms. If the organisms have been specifically bred e g. to remove C02 from the ocean, the containers can be sealed. Growing photosynthetic organisms will remove C02 from the ocean or the air. The results of photosynthesis could be used as food, fuel, a source of carbon, or it could be sunk deep in the ocean to sequester C02.

Mobile Manufacturing Systems

[0246] The manufacturing systems for the storage systems and the storage systems elements are designed to be modular so that they can be assembled, then disassembled, transported and reassembled on another site. This includes the buildings.

Robotic Manufacturing Systems

[0247] The process for the analysis of energy storage sites, the prioritization of energy storage sites, the calculation of optimized storage parameters and the construction and implementation of the energy storage system on site are as shown in Fig. 41 and include:

1. Site data collection which will be written to a storage device such as a hard disk

2. Analyse site locations for mechanical energy storage and/or generation solution or solutions and write the analysis of the site locations to the storage device (hard disk)

3. Prioritize site location based on efficiency of energy generation at the site using storage and energy generation system components and write the analysis of the site locations to the storage device. 4. Calculate and store on the storage device optimized parameters for storage and energy generation system components

5. Transmit parameters stored on the storage device to a mobile robotic manufacturing unit

6. Robotic unit builds components of energy storage system based on optimized parameters received and transmitted from the storage device

7. Energy storage/generation system(s) assembled on selected site

[0248] Examples of the process shown in Fig. 41 being applied in different scenarios are provided as follows.

Energy storage requirements from commissioning organization

[0249] The organization commissioning the energy storage installation will be setting the energy storage requirements and parameters which may include, for example: a) The amount of energy to be stored, b) when there will be energy inflow into the system for storage and how (AC, DC, voltage, current etc) c) what will the stored energy be used for and how is this energy to be output and in what form (AC, DC, voltage, current etc) and when will this output be required to happen d) if and when energy will be put back into the grid, what is response time for supplying the energy to the grid, and so on.

[0250] These requirements and parameters may be collected via a computer readable digital energy input of a computing system. The computing system may generate an output timeline, and a specification of required response times.

Mechanical Energy Storage Efficiency

[0251] With mechanical energy storage, the amount of energy stored is the mass multiplied by the vertical height it is lifted multiplied by the gravitational constant. The bigger the mass, and the longer the distance it is raised, the more energy that can be stored. Many sites (site locations) can therefore be rejected by the system early because the site locations will not be able to store the required amounts of energy.

Sites that pass the energy capacity hurdle may then be analysed for energy efficiency which may include the following analyses: a) The energy efficiency of operation - measured by comparing energy output/energy input b) The energy required for maintenance of the system e.g. the energy required to manufacture, transport and replace worn ropes c) The energy expenditure in setting up the system which will be amortized over the life of the system

Mechanical efficiency module

[0252] The mechanical efficiency module is a computerized module that calculates and/or measures the mechanical energy efficiency of particular winch/generators, ropes, pulley configurations and weights. Energy is lost by heat in storing and generating energy: winch/generators heat up, ropes heat up especially when flexed around pulleys, and pulley configurations will heat as they turn due to friction.

[0253] There are a number of limiting constraints to the configurations which may include, for example:

1. Energy storage capacity, the theoretical limits of which are height x mass x gravitational constant. If the energy stored in a suspended weight is required to be discharged within a defined period, the generator capacity should be able to convert that stored potential energy to electricity within the required period, enabling the calculation of the power of the generator system which can be made up.

2. A winch generator system may consist of the following components: a. A rope spooling mechanism b. One or more electrical engines that will be connected to a shaft that will drive a lifting mechanism to lift the weight. These engines usually require a gearbox because they operate most efficiently at relatively high rpm. If there is more than one engine, then there may be a power transmission system to connect the power of the attached engines to the shaft connected to the lifting mechanism. c. One of more generators that will convert the stored potential energy into electrical energy. The shaft driving the lifting mechanism will connect to and drive the generator(s). d. In some installations, a combined commercially available winch generator is able to used, which has the advantages of high efficiency as they have been optimized by the manufacturers, ease of installation and the use of the copper coils in the winch generator to both lift the weight and generate electricity, decreasing the energy input required for the installation. e. The system responsiveness is the time to for a configuration to respond to a request for power by delivering power to the grid and the configuration should meet the requirements specification.

3. Rope configuration. The flexibility of wire ropes reduces with rope strength and size. Extremely strong ropes usually cannot flex around a pulley. Wire ropes with diameters between 25-54mm can usually flex around moderately sized pulleys, but ropes of this diameter cannot support large weights without a pulley configuration to distribute the load.

4. Size of pulleys. There are few constraints on pulley size in an aquatic environment. With open cut mines, the height of the ropes above the mine surface will be the radius of the weight (assuming the rope is attached to the axle) minus the radius of the pulley (assuming the pulleys are attached in line between the rope and the axle). In a mineshaft, the maximum energy storage will depend on fitting in 3 dimensions a number of pulley configurations within a small space, so pulley size will be important.

5. Heavy weights. The construction of heavy weights is potentially extremely energy intensive. Weights should primarily be made of local accessed materials and the weights constructed should last for the life of the project so that the energy input into the weights can be amortized over the life of the project. Further, the construction of the weights should be done to optimize the operational efficiency of the system.

[0254] Each installation may have its individual:

1. energy storage requirements,

2. terrain if an open cut mine

3. mine shafts sizes, depths and locations,

4. the type of, and density of, the locally sourced materials from which the weights will be constructed. These materials will influence the construction technique and shape of the weights, and therefore the configuration of the optimal energy efficient

[0255] Each individual installation may be individually optimized. Computer simulation systems will be set up to run computer simulations using different configurations of winch/generator, rope, pulley and weight configurations to calculate the energy efficiency of the configuration, and the energy investment to set up the configuration. The results of these simulations will be stored in a database which other modules can query to determine initial site selection. Individual site optimization will require the detailed optimization operations.

For example, for sites utilizing weights, the efficiency of different configuration variables will calculated such as different winch generator configurations, different rope and pulley configurations and different weight designs. One or two efficient configurations will be selected and the system will vary one variable at a time, and the efficiency calculated. If the efficiency improves, then a further variation of that variable will be made and the efficiency calculated, if the process reaches a place where the efficiency starts to reduce with additional variations, then the provisional optimal value of that variable has been found. Other variables will be similarly optimized. Whilst this is not true multivariate optimization, the results should approximate the optimal. [0256] The results of the simulations will be fed into a machine learning system to analyse the importance of the variables for optimization and when sufficient data is collected, to enable a full multivariate analysis and optimization using machine learning techniques.

[0257] Initially the module will calculate energy storage efficiency based on suitable discounted manufacturer claims. Actual measured results for parameters such as energy input and output will be used as soon as they are available. Actual usage information will be fed to the simulation system when it is received and will be used to update the calculations done by the simulation system more accurate.

Electrical conversion efficiency module

[0258] High voltage AC may be delivered to energy storage platforms. This may be converted to lower voltage, higher amp current for use by winch/generators and this conversion may cause some energy loss. If the energy output of the storage system is high voltage AC, then the output of the winch/generator may be converted to higher voltage, lower current AC which will add another energy loss. If the required output is DC, then a DC generator could be used to eliminate a voltage conversion step. Initially manufacturer claims suitably discounted will be used to calculate efficiencies, but actual measured results for parameters such as energy input and output will be used as soon as they are available. The actual usage information will be updated in the algorithm on a regular basis.

Energy maintenance efficiency module

[0259] A maintenance plan will be constructed for the installation which will be entered into the system via a table and the system will calculate the energy required for the maintenance bases on a database of the energy costs of maintenance operations

Control systems optimization

[0260] A mechanical energy storage site may have multiple winch/generators in the site that can be controlled centrally and central control can provide additional efficiencies. For example, an Australian solar farm operator wishes to store energy during the day for supply when the sun is no longer shining brightly. Assume that there are often sudden increases in demand 1 hour before sunset. The control system may arrange that those configurations with the fastest measured response time are ready to provide energy in the shortest possible time. This may mean that the weights in these configurations are being lowered slowly to minimize the inertia and the time to have these configurations reach full generation capacity.

Computerized energy storage efficiency analysis modules used in all applications [0261] The mechanical efficiency module, the electrical conversion efficiency module, and the energy maintenance efficiency module will provide efficiency information for the selection of sites and the optimization of installation designed in all energy storage applications addressed herein.

Example 1 : Storing energy in water Site data collection

The data to be collected will be entered into a computerized digital geographic information system that can be queried by external systems. The collected data should be in digital electronic form suitable to be imported into a geographic information system.

Some information may only be available in analogue form such as map images and printed maps and may therefore be digitized: a) Topography and geology of seabed, which includes water depth, access to sea and whether permanent anchors can be drilled into a rock seabed b) Commercial and recreational uses which includes: shipping channels, recreation and fishing c) Weather information which includes monthly high and low tide marks and their times, a distribution of wind speed by direction, a distribution of waves height and direction including reflected waves from shoreline cliffs d) Grid connection access options and routes which includes: around a city there may be multiple options to connect. Multiple pontoons can feed into the one grid connection. A grid connection capacity may be limited by substation capacity, so running an undersea cable to a larger substation may be required, or more than one grid connection may be required. Are there reasons such as planning permissions, that may restrict or delay a grid connection? e) Areas where the site of a pontoon would be opposed on visual grounds. This will be opinion information from knowledgeable individuals f) Locations where materials for heavy submerged weights can be sources from, and locations where they can be constructed and transported and installed beneath a pontoon.

1. Analyse site locations for mechanical energy storage and/or generation solution or solutions

[0262] An approximate energy storage installation design will be developed for the purposes of selecting the most efficient sites for energy storage. Once a selection has been made by the organization commissioning the installation, detailed designs are then undertaken in stage 4.

From the organization commissioning the energy storage installation: a) Understand the amount of energy to be stored, b) when there will be energy inflow into the system for storage, c) what will the stored energy be used for and when, d) if and when energy will be put back into the grid, e) what is response time for supplying the energy to the grid, and so on.

[0263] These requirements and parameters may be collected via a computer readable digital energy input of a computing system. The computing system may generate an output timeline, and a specification of required response times.

On the computerized digital geographic information system (GIS), the following digital maps will be overlaid on the digital topographic map of the area underwater and the surrounding shoreline: a) A digital map on the GIS showing grid connection points and their capacities and routes to connect the pontoons to the grid connections. b) A digital map on the GIS showing excluded areas for the pontoons because of weather (wind, tides and waves), or existing commercial or recreational use c) A digital map on the GIS showing areas where people would oppose the sight of pontoons requiring the pontoons to be submerged most of the time. Pontoons in those areas may be equipped with a second winch/generator to submerge the pontoon. d) A digital map on the GIS showing where the seabeds that can accept permanent anchors and the depth of water at those points. Energy can be stored in these areas by submerging the pontoon without requiring weights. Areas with deeper water will have higher energy storage potential that shallower waters. However, it may be more efficient to suspend weights from pontoons if the water depth exceed say 600-1000m. e) A digital map on the GIS showing physical access barriers. This will not be an issue if the site is at sea or in a harbour connected to the sea with deep water access.

Access may be analysed closely if, for example, there is a lake or some other barrier, such as a shallow harbour entrance

Computerized energy storage efficiency analysis modules used in all applications

The mechanical efficiency module, the electrical conversion efficiency module, and the energy maintenance efficiency module will provide efficiency information for the selection of sites and the optimization of installation designed in all energy storage applications addressed herein.

Submersible pontoon energy efficiency module [0264] The most efficient design of pontoons are those that allow the pontoon to be pulled down using a fixed ground anchor in the seabed, as no heavy weights are required. The pontoons may be mass produced and floated into place. The flotation for the pontoons may be a hollow container made from a strong steel tube with hemispheres at each end and internal bracing, external bracing, including circumferential bracing, increase air pressure inside the container to withstand external pressure or a combination of the above If air pressure is used to counteract seawater pressure, then it will be monitored and topped up at the surface from compressors on the pontoon. The containers will be supported in a truss and the pontoon will be constructed from a number of such trusses. The detailed design will calculate safe and efficient container specifications based on the depth to be submerged: design for say 600m and only submerge 400m. This module will calculate the energy inputs required to manufacture the pontoon and transport it to the location where it can be submerged to store energy.

Energy efficiency module for pontoons storing energy by suspended weights [0265] These pontoons will be similar to the submersible pontoons except they do not require such strong floats as they will only be submerged to escape storms and visual pollution. This module will provide a similar calculation to the module for submersible pontoons.

Submerged weight energy efficiency calculation module.

[0266] If there are no suitable places for permanent anchors at a site, or if the waters are too deep to cost effectively drill anchors into the seabed, then pontoons may raise and lower weights, so heavy weights have to be constructed and moved into position which is not required by using pontoons and ground anchors. The submerged weight energy efficiency calculation module calculated the energy input required to construct these weights and move them into location under the pontoon for energy storage. The module includes locations where suitably dense materials for the weights can be obtained, sites for the construction of heavy weights from these materials, the weight fabrication plant, a plan to get the heavy weights floated underneath the pontoon which will raise and lower them, and a way to tow the pontoon into place may also be determined. The energy expenditure of each of the above aspects may also be calculated for amortization of the energy input over the lifetime of the weight. Prioritize site location based on efficiency of site [0267] The requirements of the organization commissioning the energy storage will usually have requirements that will translate for the purposes of calculation into distance from grid connection points. Multiple grid connection points may be required as the grid connections may be what limits the capacity of the energy storage system. There may be other requirements.

[0268] Based on these requirements and limitations, the estimate the energy storage efficiency of the sites under consideration and prioritize sites accordingly by calculating the potential energy that can be stored in a suitable particular area within a certain distance of a grid connection point.

[0269] If a very short response time is required, a battery may be required to bridge the gap between the request and when the inertial forces are overcome.

Calculate and store optimized parameters for storage and energy generation system components

This step involves the detailed design of the energy storage system at a site and the design of the components of the system including: a) The mechanical efficiency module, the electrical conversion efficiency module, and the energy maintenance efficiency module will provide efficiency information to be used to provide detailed plans of their respective areas b) The most efficient designs of the pontoons used for storing energy by raising and lowering heavy weights using the above modules, c) The sourcing of materials for heavy weights, the construction of heavy weight components, the building of the heavy weights from the components, and how to safely get the heavy weight in place for the storage store energy using the above modules. d) The planned lifetime of the components

2. Transmit parameters to a robotic manufacturing unit, which may be a mobile manufacturing unit.

3. Robotic unit builds components of energy storage system based on optimized parameters 4. Energy storage/generation system(s) assembled on selected site Example 2: An Open Cut Mine

[0270] Some open cut mines are vast and can store large quantities of energy. However, there may be no grid connections nearby or the grid connections cannot transfer all the energy that could be stored on the site. Using the grid when it has low utilization, e g. at night may enable a significant amount of energy to be transmitted provided that it can be stored close to the geographic areas where it will be consumed, e.g. close to a substation in a city. Otherwise the stored energy can be used to reduce or eliminate diesel generated electricity at the mine site or to power 24/7 other processes such as renewable generation which can be shipped to markets by the existing rail infrastructure.

[0271] In large open cut mine sites, it may be that the parts of the mine site that have the higher energy storage efficiency and/or capability can be chosen for energy storage, rather than trying to maximize energy stored at the mine site.

[0272] The requirements of the organization commissioning the energy storage installation will therefore determine the energy storage configuration, which will impact the energy storage efficiency.

1. Site data collection includes a) Topography and geology of the open cut mine and surrounding areas. Of particular importance are: a. The topography of the mine, which can be sourced from mining records or can be resurveyed by drones b. The elevation of the mine determines the energy that can be stored in a single weight c. The geology of the mine showing the different geological layers d. The slope of the mine as object will not roll well down rough slopes with a shallow incline e. The overall smoothness of the mine surface f. The existence of obstacles in the mine surface that will impede a weight rolling down the mine surface. i. A major obstacle could be roads built into the mine for trucks to use to transport mined ore. Some of these mine roads are sloped towards the mine wall. Rollers with insufficient energy/momentum will not be able to go up and over the road surface. ii. Are there other obstacles such as large rocks that should be navigated around or navigated over? This may require the use of a drone to very accurately map the mine surface. b) The pressure, compressibility and the ability of the mine surface to be compacted so that higher pressures can be supported by a compacted mine surface. Compacting the mine surface will require energy but a compacted surface will support higher pressures and heavier weights, and greater energy storage efficiency. The compressibility can be calculated from the known geology of the mine surface.

Greater accuracy can be achieved by rolling a small heavy weight down the mine surface at various points and measuring the indentations which can be done by drones. If this is done shortly after rain, then the compactability of the mine surface after rain can be measured. c) Safe areas in the mine where there are no people working which are suitable for energy storage d) Grid connection access options and routes. It may be that there are no suitable grid connections and that the energy storage is to minimize diesel generated electricity costs, and use the stored energy for other purposes such generate chemicals like ammonium nitrate that could be used in mining operations, the generation of fuel for transport from the mine by rail, or the processing of minerals e.g. iron ore into steel e) Locations close to the mine where dense materials can be extracted and used for the mass of the heavy weights used to store energy f) Proximity to clean water used for the construction of the heavy weights and for other purposes such as the generation of hydrogen

2. Analyse site locations for mechanical energy storage and/or generation solution or solutions

[0273] An approximate energy storage installation design will be developed for the purposes of selecting the most efficient sites for energy storage. Once a selection has been made by the organization commissioning the installation, detailed designs are then undertaken in stage 4.

[0274] Energy storage efficiency can be optimized if the energy storage system components can be designed to work efficiently in specific mines without site preparation.

The dimensions of rollers will be determined by the following constraints: a) The rollers are as heavy as possible so store as much energy as possible b) The weight of rollers that can be supported by the mine surface will depend on the surface area of the roller contacting the mine surface, the pressure capacity of the mine surface to support weight, and the slope of the mine surface at any given point, which will determine the force perpendicular to the mine surface c) The rollers are strong enough to roll over some obstacles, or narrow enough to be able to steer a path between obstacles cannot roll over, so that the rollers can operate from the bottom of the mine to the top. d) The rollers are vertically stable, i.e. not topple over, so large thin wheels are usually constructed as two wheels connected by an axle. e) Rollers that can roll over the mine surface efficiently with little loss of energy: a. For those parts of a mine where the sides of the mine are rock, heavy thin rollers can be efficiently used b. For softer mine surfaces, the roller pressure (area of the roller in contact with the mine surface divided by the weight) will be limited requiring wider rollers and/or use of tyres to reduce the pressure. f) The shape of the rollers will in part be determined by the density of the material used for mass. A more dense material used for mass will allow smaller rollers of the same mass as a larger roller, and allow for heavier rollers of a particular size and shape g) Rollers that are smaller horizontally will allow more of these rollers to be fitted onto the surface of the mine

Roads in opencut mines are frequently encountered. The obstacles created by roads can be overcome by the following designs: a) Rolling the roller with sufficient momentum so that it can overcome the rise of the road and roll over the road to the slope b) A 3m diameter roller may be required to climb say 3-6m from where it contacts the road, whereas a 6m diameter roller may contact the road near the edge of the road and be required to climb a much smaller distance c) If two rollers are coupled by rods, then the top roller may force the bottom roller up the road and over the other side, whereupon the lower roller may pull the second roller over the road. This may be extended to 3 or more rollers.

Computerized energy storage efficiency analysis modules used in all applications

The mechanical efficiency module, the electrical conversion efficiency module, and the energy maintenance efficiency module will provide efficiency information for the selection of sites and the optimization of installation designed in all energy storage applications addressed herein.

A series of computerized analysis modules analyse the open cut mine site data with outputs which include:

• Road Profile Module is a computer module that measures the road profiles across the entire mine at a specified distance between analysis points, such as 5 m

• Non Road Obstacle Module measures irregularities in the surface over specified dimensions, such as a rock extending 500mm from the surface

• Mine Surface Module is a computer module that calculates the roughness of the mine surface, the steepness of the mine surface, the pressure that the mine surface can support at that point (this is calculated from the geology of the mine surface and the known pressures that the different geologies can support), and the compactability of the mine surface at that point which can be measured directly at sample points • Roller Path Module is a computer module that locates paths on the mine surface that fit between non road obstacles and calculates the height, steepness, straightness, width of the path at agreed analysis points (e.g. every 5m), the pressures that can be by the mine surface on that path, and the number and location of obstacles that may need to be removed to make the path straight It also calculated the vertical straightness of the path. The ropes suspending rollers will not touch the mine surface with vertically concave paths. With vertically convex paths, the diameter of the roller may overcome some convexity. However, if there is a significant convexity on a path, and one rope, then two rollers may need to joined by an axle and permanent rollers may need to be installed at the point of maximum convexity. The two rollers may need to pass on either side of the permanently installed rollers. If there is one roller and two ropes, then the rollers on the mine surface may be on either side of the roller and the roller will pass between them. Having two ropes lifting a roller allows for greater roller weight and also for steering of the roller. The module may also calculates the circumference of any turn required by a steered roller to avoid an obstacle.

• The Road Obstacle Calculation Module is a computer program that will take a roller design and forecast the energy and momentum that a particular sized roller of a specified mass may need to have to roll over a particular road profile

• Mine Surface Compactability Module is a computer module that will calculate the compaction that can be achieved by a particular area in the mine surface multiple times with a roller of a particular weight or with a roller that is made heavier by the addition of more weight. The module also calculates the improvements to energy efficiency because larger weights can be used and they will roll more efficiently. Input to this model can come from sample points where the compaction has been directly measured a) Roller Construction Energy Efficiency Module is a computer module that calculates the energy inputs required to make, transport and install the heavy rollers when constructed a different sites close to the mine site in question. The module also calculates the most energy efficient way to construct heavy weights in these shapes from local materials in a robotic plant close to the mine site by adding up the energy inputs which include: steel used in the construction of the weight, extraction of local materials for the mass of the weights, the energy input of the cement to solidify the local materials (if used), the energy involved in the construction, transport and installation of the weights etc. The module will also compare different locations of the robotic plant.

The analysis will be in the following stages: b) The Roller Design Optimization Module is a computerized analysis module that takes a roller design and calculates the energy that that roller can store in different paths from the top to be bottom of the mine by querying the above computerized analysis modules, and the energy efficiency of the roller storing the energy c) The Roller Design Optimization Modules will then vary the roller design one variable at a time to see if more or less energy is stored and how the energy efficiency is affected with the changed variable without impacting other constraints e.g. making the roller too long to fit between a significant number of obstacles. A variable that is likely to provide a large optimization benefit is chosen first. If the energy storage and efficiency improves, then expand increase the change. If the changed variable reduces the energy efficiency, then change the variable the other way. Then experiment with other variables. Variables that are likely to have a higher optimization value will be optimized before variables estimated to have a lower optimization value. d) Several different roller configurations will be optimized by the Roller Design Optimization Module, such as a single roller with hard surfaces, two large diameter rollers connected by an axle, a pair of rollers joined together to reduce the momentum required to roll over a road, rollers with tyres to reduce the pressure on the surface etc. e) If areas of the mine site with softer mine surfaces are required to store energy, calculate energy compaction plans using the Mine Surface Compactability Module and then optimize the roller design for that area based on the compaction plans. f) Once a number of these Roller Design Optimization Module calculations have been carried out, take the solutions with the largest energy stored and the highest energy efficiency and estimate the amortized energy input over the life of the roller to select the most energy efficient roller g) Model winch/generator installations at the top of the mine overlooking the paths found for the rollers to use to find the optimal positioning and design of the winch/generators installations and estimate the energy inputs into building these installations and amortize this energy over the lifetime of the installation. h) Model the compaction of the mine surface (if the surface is not strong rock) as rollers go up and down the surface, and developing a plan to add mass to rollers as the compacted surface can support higher pressures and greater weights, and then select the optimal roller design. Or it is possible that rollers using tyres can be used in an area while the surface is being compacted and then moved to another area of the mine when the compacted mine surface can support rollers with steel circumferences i) It is possible that a small number of different rollers designs could be used in one mine due to different topographies and geologies in different parts of the mine

3. Prioritize site location based on efficiency of site

Using the calculation processes of energy storage efficiency in step 2 above, select the mine sites or different areas within a mine site and prioritize the most energy efficient sites or areas with a mine site accordingly. Where mine sites or areas within mine sites have similar energy efficiency, select the site with the best long term prospects for energy storage, such as a site that may have its grid connection capacity upgraded.

4. Calculate and store optimizes parameters for storage and energy generation system components.

This step involves the detailed design and optimization of the energy storage system at chosen site and the optimized components of the system using the modules described above. 5. Transmit parameters to a robotic manufacturing unit, which may be a mobile manufacturing unit.

6. Robotic unit builds components of energy storage system based on optimized parameters.

7. Energy storage/generation system(s) assembled on selected site.

Example 3: Vertical Mineshaft

1. Site data collection

The data to be collected will be entered into a computerized digital geographic information system that can be queried by external systems. The collected data should be in digital electronic form suitable to be imported into a geographic information system. Some information may only be available in analogue form such as map images and printed maps and may therefore be digitized.

Mineshaft energy storage can be installed in existing mine shafts, or new shafts can be drilled close to where energy is produced, such as a solar or wind farm, where energy is used, such as a car park of a shopping centre, or where energy storage is required for grid stability, such as close to a substation. The energy storage facility can be buried underground, so that the car park or a park could be returned back to its original use.

Core site data includes: a) Information about access to the mineshaft site b) The geology of the site and the load bearing capacity of the ground where the mineshaft is located or proposed c) Areas that can be used for construction of the energy storage facility and construction of the weights d) Electrical connection information: is the installation to be connected to the grid, or is it to store and generate electricity for e.g. a solar farm which will use its existing grid connection but transfer power when the solar farm is not generating power e) Location of suitable dense materials for constructing the weights f) Access to clean water

2. Analyse site locations for mechanical energy storage and/or generation solution or solutions

An approximate energy storage installation design will be developed for the purposes of selecting the most efficient existing mineshafts sites for energy storage or to develop the specifications of a new mineshaft. Once a selection has been made by the organization commissioning the installation, detailed designs are then undertaken in stage 4.

From the organization commissioning the energy storage installation: a) Understand the amount of energy to be stored, b) when there will be energy inflow into the system for storage, c) what will the stored energy be used for and when, d) if and when energy will be put back into the grid, e) what is response time for supplying the energy to the grid, and so on.

These requirements and parameters may be collected via a computer readable digital energy input of a computing system. The computing system may generate an output timeline, and a specification of required response times

Common energy storage efficiency modules

The mechanical efficiency module, the electrical conversion efficiency module, and the energy maintenance efficiency module will provide efficiency information for the initial selection of the sites.

3. Prioritize site location based on efficiency of site

Based on the power storage and generation requirements and limitations, estimate the energy storage efficiency of the sites under consideration and prioritize the existing mineshafts and/or new mineshafts.

If a very short response time is required, a battery may be required to bridge the gap between the request and when the inertial forces are overcome.

4. Calculate and store optimized parameters for storage and energy generation system components

This step involves the detailed optimization of the design of the energy storage system at a site and the design of the components of the system using the computerized simulation system linked to the relevant computerized analysis systems by varying one variable at a time to optimize that variable, and then varying the next variable until the optimal is found for all variables. Analysis modules to be used in the optimization include: a) The mechanical efficiency module, the electrical conversion efficiency module, and the energy maintenance efficiency module will provide efficiency information to be used to provide detailed plans of their respective areas. b) The sourcing of materials for heavy weights, the construction of heavy weight components, the building of the heavy weights from the components, and how to safely get the heavy weight in place for the storage store energy using the above modules. c) The planned lifetime of the components.

5. Transmit parameters to a robotic manufacturing unit, which may be a mobile manufacturing unit.

6. Robotic unit builds components of energy storage system based on optimized parameters. 7. Energy storage/generation system(s) assembled on selected site.

The following factors may also be taking into account by the system:

1. Site acquisition costs a. Low site acquisition costs at sea. b. No site acquisition costs of installing energy storage in an existing mine. c. No site acquisition costs for constructing an energy storage facility e.g. in a warehouse carpark or in an existing solar farm. d. Bury energy installations in carparks and in local parks near to a substation, so there are no opportunity costs.

2. Connection to the grid a. Use existing connections - Large warehouses for example may buy energy when cheap and store it for when energy is expensive - Large warehouses may install solar panels on its roof and store this electricity. b. Solar farms transfer their energy out of daylight hours when grid utilization is low. c. At some stage, the grid operator will want to use energy storage to stabilize the grid and it will be much easier to get a satisfactory arrangement if it is driven by the grid operator.

3. Use of existing infrastructure without upgrading a. Large warehouses may still be buying power. b. A solar farm can store electricity and sell when dark with no change to grid connection. c. A hydrogen generator may set up a solar farm (possibly next to an existing farm with a grid connection) and store the energy and transmit this energy to the hydrogen generation plant at night. d. Use existing rail connections to ship hydrogen or other value added materials from open cut mine.

[0275] A site selection system is also envisaged, which is illustrated by way of a flow chart in Figure 41. The site selection system includes determining a method or methods of storage depending factors such as if short-term or long-term storage is required, the terrain or if the use of multiple terrains is required.

[0276] It is also envisaged that the site selection system can design the All-Terrain Rollers as follows:

• Select the type of roller (a steel roller filler with local material is used in this example)

• Design the roller - diameter, wall thickness and length of roller - size and shape of axle

• Design the equipment required to manufacture the rollers such as casting jigs

• Transport the steel in a roll to the site

• Sends instructions to automated equipment. Example instructions are as follows: o Cut the steel into properly sized sheets o Roll the sheets o Hold the rolled sheets in a jig and automatically weld the steel into a cylinder o Transfer the cylinder to a casting jig

• Accurately and securely locate the axle in the centre of the casting jig together with any cardboard tube to reduce weight

• Weld on one plate to seal one side of the cylinder (called the cylinder base)

• Rotate the cylinder vertically with the cylinder base at the bottom, so that cement or other material can fill the cylinder

• Rotate horizontally when cement has solidified

• Attach bearings to the axles

• Remove the cylinder from the jig and roll into place ready for lowering [0277] The site selection system can also determine the method or methods of energy generation. For example, based on the operator inputs, the system can select a method of energy generation such as wave power, tidal, current or solar. Then the system can design the energy generation facility. The system may design a floating pontoon, for example. Then the components that are automatically designed and built by the system, can be assembled on site.

Control Systems

[0278] In summary, the use of a large number of monitoring devices will generate a lot of information that can be collected by a product like Kinesis® and stored in a database like DynamoDB® which can then be reformatted for machine learning analysis. Positional information of the rollers, rope tensions, generator and winch heat and so on can all be measured and recorded. Added information like meteorological information, soil compaction can be monitored as can water in the soil and other relevant information put into the database. Machine learning algorithms can then be run to optimize the operation of the system.

[0279] The control systems can be broken in several different components which can be added together to produce a control system for different installations:

[0280] Determining locations that will be suitable for the gravity storage of energy. This includes geographic and topographic information, tides and current, water depth, geological and hydrological information, proximity to grid connections, location of renewable power generation facilities, land prices and so on. Using a systematic approach which can be developed into an artificial intelligence application using this information will enable the selection of energy efficient and low cost sites where the storage of energy will be efficient and cost effective.

[0281] Predicting the price of electricity. A model will be developed that will make use of machine learning algorithms. Data to be collected and analysed will include weather (temperature - cold temperatures will mean heating, hot temperatures, air conditioning), cloud cover for solar generation capacity, wind for wind generation capacity (these will be required to be known at locations where wind and solar farms are located)), climatic information (in drought, water may be more valuable than the hydro-electricity it could be used to generate, so other forms of storage will be used first), tidal information (it is possible to generate some energy from tidal power where weights are hung over cliffs into the water, and tides may be used to calculate input to the grid from tidal power stations), wave information (it is possible for the water storage systems in this document to generate electricity from wave power and wave power could be used by other systems to generate electricity for the grid), historical electricity prices in the locations where the storage facilities are located, information about the grid capacity at locations where storage units are located, real time generation capacity (a fault may have taken a power station offline), availability of other energy storage (e.g. in batteries) and their location on the grid, real time grid infrastructure issues (break downs, storms, bushfires etc) and so on. Additional information affecting climate such as solar flares can be added to improve predictions. The grids in Australian states are interconnected and sometimes the interconnections can be near to capacity especially in extreme weather events. In these situations, having stored energy in various jurisdictions may produce a price arbitrage

[0282] Managing diverse energy storage systems across multiple installations. Different installations will be located in different areas with different grid connections and these storage locations may have different storage levels and different capacities to respond quickly to requests for absorbing or releasing energy. Managing installations as a whole is likely to have significant efficiency benefits.

[0283] Efficiency optimizing the uninterrupted flow of energy. For example, in an open cut mine, hitting a road may slow down the flow of electricity until the obstacle is overcome. The slow down may be compensated for by releasing the weight so that it has sufficient momentum to roll over the obstacle or by having additional winch/generators compensate in the short term until the weight has cleared the obstacle. In addition, the control system using steerable weights can plot a path for the weight that will avoid obstacles like trees and rocks, allowing more terrain to be used to store energy.

[0284] Managing each installation. This requires knowing in detail all aspects of the operations of the storage facilities, including where the weights are, what is their proximity to other weights, are the weights connected to the system or are they being stored, what is the status of each winch/generator (including information such as: is it stationary, generating or storing energy, and at what rate, what is its temperature, what is the tension on the rope (with vertical drops, the tension on the rope should be the same except at the top and bottom, so monitoring the tension can alert to problems - additional information relating to rope tension is discussed in the open cut mine situation below), how much energy is stored and how much more energy could be stored by that winch/generator and so on)). Stationary weights, especially rollers, may have to overcome inertia to move and if a fast response to changed grid conditions is required, the control system may determine that this can be achieved most efficiently by releasing a moving roller rather than a static one.

[0285] Additional control systems required to manage an installation on or under the water. Waves and tides may reduce the tension of the rope and the winch/generator can store energy more efficiently when the tension is low and generate electricity when the tension is high.

The control system will collect tidal, wind, sea temperature, tidal flows, ocean currents and so on to optimize storage and the generation of energy by tidal and wave power by using the tidal energy and wave power to reel in the rope when the tension is low and generate energy when the tension is increased. This information will also allow for the optimization of generation of electricity by using turbines added to the float or suspended from the float. If there are multiple installations, then it will be possible to see which installation is better optimized and hypotheses about how to improve efficiency by changing location can be experimentally tested. This will develop a database of information that can be applied in other situations to optimize both energy storage and energy generation possibilities.

[0286] The control systems for all installations will be developed progressively. The initial control system will be created using a traditional deterministic approach. Rules of physics (such as how to resolve forces on rollers) will be embedded in the control system. As data is collected, guided learning will be utilized to improve efficiencies and this will morph into a deep learning process as more data is collected.

[0287] There would be a large number of monitors on the floats to variables that can be used to optimize the operation of the floats, both as storage and as electricity generation systems, including measuring water pressure, pressure inside the float, cable tension, cable extension, wind, wave, tide information, and so on.

[0288] Monitoring and control systems can be connected to the land via the electricity cable with the data transmitted in the electricity cable itself. This should include systems to measure the pressure of the water, the pressure inside the floats, the tilt and orientation of the floats, the length of the cable, how far the float moves in a wave surge or tidal flow, whether additional energy can be stored by using a battery to store electricity when the cable is taught and use this power and the power being stored to sink the float when the cable is less taught.

[0289] Further metrological information can be collected from installations on land and from weather forecasting agencies.

[0290] The float system will be a floating research platform that will be self optimizing by using machine learning generated algorithms to increase the efficiency of the device and possibly be able to use the device to capture additional energy from wind and tides.

[0291] The additional control systems for an open cut mine are set out below. a. Building a virtual system to optimize the design and operation by simulation will involve the collection of information listed below for analysis to optimize the efficiency of the system. b. Experimentation with the design and construction of low energy input, energy efficient and low cost but durable rolling weights which can have the desired diameter to roll over objects and the desired area and weight to operate efficiently on the surface of that mine. c. Understanding the size, weight and strength constraints for the weights to be able to roll over obstacles - a large conical rock could put enormous force on a roller. It is best to avoid obstacles by selecting paths or to do the minimum remediation. d. Collecting and analyzing the detailed topography of the mine. e. Designing and optimizing the structures for the winch/generators to use to lower the weights. f. Automating the storage of weights offline at the top and bottom of the mine (connection and disconnection of weights etc). g. Experiments to improve the response times of the systems e.g. by having the weights being slowly lowered to reduce inertial delays compared to stationary weights. h. Experiments with steering of weights (e.g. via 2 ropes or connecting rollers together) to develop algorithms that can accurately steer weights on different terrains and different topographies. i. Control systems to allow for weights to overlap of the slope and avoid collisions by being at different heights in order to maximize the amount of weight stored on the sides of the mine. j . Optimizing the winch/generator and rope configurations to ensure that the maximum weights can be stored and that the desired storage input and output is achieved. k. Soil compaction experiments to increase the efficiency of the system include logging and analyzing the following data: l. Varying the way rollers are moved by lowering the roller a small distance down, then up and then down a bit further then up, and so on, which in some terrain will compact the ground more efficiently than simply rolling the roller down to the base and then up - there can be multiple experiments on how best to compact the terrain to make the system as efficient as possible m. Weather effects - measuring

I. if and how rain softens the ground and make energy storage less efficient

II. how repeated passes of the roller affect the porosity of the sides of the mine

III. how rain softened terrain be best compacted n. Using different rollers with different surface areas and weights at different times on different slopes with different geology o. Adding mass to rollers as the ground compacts by e.g. filling some on the tubes inserted into the rollers to design the weights of the rollers to work most efficiently on the current terrain. p. Using vibration to compact the terrain q. Treating the surface e g. with bitumen to make rolling more energy efficient r. Using this information to optimize the storage of energy and operating energy efficiency and minimize operating costs

[0292] Other terrain experiments that will generate data to be analysed for optimization include: a. Allowing the roller to move at a sufficient speed to overcome obstacles like roads b. Chaining weights together to use the combined weight to overcome a barrier

[0293] There will be extensive data collection which will include topography of the site, information about each roller as manufactured (size, weight etc), recording the energy sent to a winch engine and the progress of the rollers being winched up (this will give a measurement of the efficiency of energy storage), a similar measurement of the generation of energy, a system to measure the compaction of the soil by measuring the location of each roller compared to the original topographical map. [0294] Machine learning algorithms will be applied to better understand the parameters like the terrain compaction to better optimize the energy storage of the system, including how rain and drought affect the energy storage efficiency.

[0295] Control system will allow rollers to be sited very close to each other horizontally and vertically allowing a greater mass to be suspended than would be possible with rails. The shorter the roller is horizontally, the more rollers than can be deployed horizontally in a given area. The bigger the diameter, the greater the mass (increasing at the square of the radius).

[0296] Rollers can be overlapped so that two rollers are spaced less than a roller length apart and a third roller in either above or below the roller. The key thing is the wires don’t get tangled because a roller deviated from its path, and that the control system will keep the rollers separated vertically. One way to do this is to run the rollers for a while and track their paths. Where the paths are stable and the ropes will not get tangled, additional rollers can be added above these weights.

[0297] Although it is relatively simple to chain the rollers together, it is possible to have a roller on a cable directly below another roller which has a separate cable and have the cable holding the lower lifted over the top roller. This has the benefit that it increases the number of winches which increased the dynamic energy storage capability of the mine. The issue to be avoided is cable tangling. The cables are taut allowing guide rollers to be mounted above rollers to avoid cable entanglement. This is shown best in Figure 27

[0298] The control system can be simple using dumb rollers and measuring the length of rope that has been extended. The control system would work by lowering the lower weights first when generating electricity and raising the upper weights first when storing energy.

[0299] However, to get all the data for the machine learning database, if it is not possible to get this information from devices located on the terrain, it is possible to locate sensors on the rollers and communicate wirelessly with communications and sensors power by solar cells mounted on the rollers.

[0300] The mine storage capacity can be better optimized if it is accurately surveyed. Topological survey information might be obtained from the mining company or produced using modern survey equipment that can take automated readings. Usage of properly equipped drones may also be able to quickly provide information of sufficient accuracy and drones can also be used to locate rollers and to validate calculated data.

[0301] The horizontal location of the rollers can be measured optically from the top. Adding measurement points to the rollers may increase accuracy of the optical measurement.

[0302] If the open cut mine has water at the bottom of the mine, hollow weights can be filled with water. Winched to the top, and the water then stored for long term energy storage. Rainwater catchment at the top of the mine will further add to the energy store.

Alternatively, where there is low cost power, or if a solar panels are installed, the water can be pumped up to the top of the cliff and stored in a container until the energy price is high, when it can then be used to fill ATR’s and have them rolled down the slope generating energy.

[0303] Advantages of at least one of the preferred embodiments will now be described: a. Buying cheap energy when prices are low and selling when prices are high is preferable. In some oversupply situations, (such as on warm (but not hot enough to run air conditioners), sunny and windy weekend days or holidays when industry is not using electricity) organizations can be paid to accept energy. b. Contracting to provide long term energy storage that will be called upon when e g. it is cloudy and there is little wind for a number of days. c. Balancing the grid: being able to respond very quickly to requests to provide or store electricity can generate significant revenues. The storage systems disclosed herein can be experimentally optimized to respond quickly. For example, weights on cliffs that are slowly being lowered to generate electricity can probably very quickly accelerate the rate of energy generation by speeding up the lowering of the weight, as there will be little inertia to be overcome. This may be considerably faster than lowering a stationary weight in an open cut mine where there can be inertia from the weight and generator and friction from the weight to be overcome. d. Selling stored electricity to a particular customer e.g. a factory at nighttime for use by the factory or for storage at the factory. The benefit of this arrangements is that the electricity grid has surplus capacity and the transmission costs are low. Also electricity can be transferred between storage sites when the grid capacity is low. However, this does come at a cost as the generation of stored into electricity and the storage to electricity are not 100% efficient and both lose energy. The higher efficiency the systems have to generate and store energy, the greater ability to cost effectively transfer energy between storage facilities. e. Generating, storing and selling generated energy