DESCRIPTION: This PCT Application incorporates by reference (to the extent that does not conflict with the disclosure contained herein) and claims the benefit and priority of Australian

Provisional Applications having Application Nos. 2017902833, 2017903779. 2017904676 and filed on 19/07/2017, 17/09/2017 and 20/11/2017 respectively for "Ceiling And Wall Battery Panels" commonly owned with this application.

FIELD OF THE INVENTION

The present versions of the invention relate generally to ceiling and wall panels used to provide battery storage systems for renewable energy storage in buildings.

BACKGROUND OF THE INVENTION

Over the last few years commercial building owners, home owners and businesses all around the world have been installing solar panels on their rooftops as solar power has become increasingly more affordable and more efficient. This has allowed them to significantly reduce their power bill during the day when there is sunlight.

Coupling the solar panels with storage batteries, and storing the surplus power during the day and then using it at night, allows these businesses, commercial building owners and home owners to reduce their power bill even further. Battery storage systems are required that connect to the solar panel outside and provide power to the building usually through either a DC-DC converter or through an AC inverter circuit.

In the past, the batteries have typically used either lead-acid or lithium-ion technology. They often look like a large car battery and, because banks of these batteries are normally required to be connected together to achieve the required level of storage capacity and voltage output, they are usually big, expensive and often require ongoing maintenance. As a result, the occupants of these buildings normally prefer them to be stored somewhere out of sight in a basement or store room. But sometimes this is just not possible. In addition, lead-acid batteries have dangerous chemicals in them, so they must be contained to avoid spills. They also put out hydrogen and oxygen gas while being charged, and these should be vented to the outdoors.

More recently, battery storage for renewable energy systems, primarily for houses, have been developed, typically using a large number of lithium-ion batteries all connected together inside a metal enclosure which is usually mounted on a wall of the residential building, usually somewhere well out of sight. The designers of these systems usually try to pack as many batteries as they possibly can into the smallest enclosure they possibly can. The purpose is to minimize the size of the enclosure that typically is going to be bolted onto a wall of the building. .

Lithium-ion batteries get hot under certain conditions, and have been known to burst into flames. Putting a large number of lithium-ion batteries inside an enclosure, packed up against one another creates a potential hazard. One battery overheating and bursting into flames could potentially cause other batteries stacked against it to overheat and catch on fire, causing a chain reaction.

Manufacturers of these battery storage systems usually include a cooling system in the enclosure in order to prevent this but the cooling system consumes some of the power of the battery storage system to do this.

All of the currently available battery storage systems require installation and maintenance by a highly qualified and trained technician, and the cost of installation is not cheap.

DESCRIPTION OF THE PRIOR ART

(1) U.S. Pat. No. 8618696B2 WIRELESS ENERGY TRANSFER SYSTEMS, discloses systems and methods that may be used for wireless transfer of power from solar photovoltaic (PV) panels.

(2) U.S. Pat. No. 20160329713A1 CONTROLLING A MICROGRID, discloses a method for controlling the elements connected to a microgrid.

(3) WO2016200398 Al MICROGRID SYSTEM AND CONTROLLER. The disclosure relates to power generation and consumption and, more particularly, to controlling microgrid thermal and/or electrical power supply, storage and consumption. (4) U.S. Pat. No. 20130015703A1MICROGRID, discloses systems and methods of micro-grids, of various different kinds, that are tailored to suit the power requirements and characteristics of the site that they serve.

(5) U.S. Pat. No. 8766488B2 ADJUSTABLE INDUCTIVE POWER TRANSMISSION

PLATFORM, discloses an adjustable inductive power transmission platform which includes inductive power outlets embedded into adjustable modules having multiple configurations.

(6) U.S. Pat. No. 20070273550A1 SMART CEILING TILES AND METHOD OF USING, discloses systems and methods relating generally to ceiling tiles as part of suspended ceiling systems used with visual indicia, signals, and/or markers for informative, educational, advertising and other communication uses. Other versions of the invention relate to a "smart" ceiling using state-of-the-art technologies to provide communication between devices and systems.

(7) US4098965 FLAT BATTERIES AND METHOD OF MAKING THE SAME. This invention relates to primary batteries, and particularly to novel methods and apparatus for constructing thin, flat cells and batteries.

(8) Stanford News Service: NANOTECHNOLOGY SPARKS ENERGY STORAGE ON PAPER AND CLOTH. This article describes how a research group at Stanford University had found a way to manufacture lightweight paper sheet batteries and supercapacitors.

https://news.stanford.edu/pr/2010/pr-cui-aaas-nanotechnol ogv.html.

(9) SCIENTISTS CREATE SPRAY-ON BATTERY PAINT. This article explains how scientists at Rice University in Texas have developed a method for creating spray-on batteries.

https://www.digitaltrends.com/cool-tech scientists-create-sprav-on-battery-paint

(10) THE TESLA POWERWALL. Elon Musk's Tesla Powerwall is a good example of the prior art currently being applied for renewable energy storage in homes, https://www.tesla.com/powerwall

None of the cited prior art discloses the use of ceiling tiles for medium scale battery storage as required by residential and commercial renewable energy systems.

Further, none disclose the new and useful feature of one embodiment of the present invention which permits the tiles to be electrically connected either in series or parallel simply by rotating the tiles. Further, none disclose the new and useful feature of a renewable energy battery store where the voltage and amp-hour capacity required in a building can be easily achieved by changing some of the battery tile parameters and the way the battery tiles are connected in series and in parallel.

Further, none disclose the new and useful feature of one embodiment of the present invention which uses the same metal connectors for both securing the tiles to the surface they are mounted on and also providing low resistance electrical connection between panels.

Further, none disclose the new and useful feature of all embodiments of the present invention which makes the replacement or servicing of individual batteries, in this case battery tiles, much simpler because they are easy to access.

BRIEF SUMMARY OF THE INVENTION

The present invention comprises a method and a system for utilizing existing and new battery technologies in battery storage systems for renewable energy such as but not limited to solar power, by integrating the batteries into wall and/or ceiling panels which can be connected together electrically to configure the storage capacity and voltage output to match the requirements of the electrical site, which could be for a residential or commercial building or part thereof. Figure 32 is a diagram of a solar energy system showing one possible configuration for how the battery storage system of the present invention could be incorporated into such a solar energy system. Other system configurations are also possible.

Said battery panels can also be used as the battery storage for building emergency lighting systems and can be used in other situations where power off the grid may be unavailable. Said battery panels are light, easily installed, require no, or very little, additional space in a home or office building, are long-life and almost, or totally, maintenance-free.

There is currently a lot of time, money and effort being put into battery technology research, with many new battery discoveries coming out of universities and companies all over the world in just the last two years. Many of these are small and light weight, and at least some of these will be ideally suitable for use in battery storage systems in renewable energy systems.

Although in the drawings and descriptions, for the preferred embodiments described herein, the battery panels described are ceiling and/or wall tiles, but it will be well understood by a Person of Ordinary Skill in the Art that the panels could also take on other forms such as but not limited to floor tiles, wall paintings, panels made of wood or other materials that make up the actual wall or ceiling itself, and many other forms.

Although the drawings and descriptions, for the preferred embodiment described herein, refer mainly to super-capacitor paper batteries and suspended ceilings, the present invention is also suitable for other methods of installation and other new battery technologies, and many of these can also be used and may even be more suitable in some installations. Two other embodiments will also be described in some detail, and some additional variations to the preferred embodiment will also be described.

Advantages over the prior art include:

1) The ability to hide the battery storage system as part of the decor of the building will be very attractive to many people. For example, very few people who live in high rise building apartments will prefer to have a "cabinet" style battery storage system compared to this unless it costs a lot more.

2) The batteries are close to where much of the power is required. This is important for DC voltage systems as it minimizes voltage losses that you would otherwise get on long cable runs.

3) The installation can be easily scaled to configure the storage capacity and voltage output to match the exact requirements of the building whether it be a multi-story commercial building, a one- or two-storey home, or an apartment.

4) The user can also start off with a smaller installation at lower cost and expand the system as required in the future.

5) It is possible that a battery tile system could be installed by a home handyman given suitable instructions. These are low voltage systems that may not require a licensed electrician to install them.

6) Many home handymen will also be able to perform all, or most, of the maintenance if and when it becomes necessary. It could be relatively simple to replace battery tiles, and a battery monitoring system could make it easier by identifying faulty or under-performing battery tiles.

8) The battery ceiling tile system is perfect for emergency lighting systems as low power LED lights can be built into the ceiling tile and connected directly to the battery in that tile. 9) Many buildings such as skyscrapers are not good candidates for rooftop solar power systems but solar powered windows using transparent solar panels look set to change that (see references below).

Battery tiles are the perfect partner for solar powered windows. Each floor of a multi-story building can have it's own solar power system, separate from every other floor.

10) A battery storage system made up from ceiling tiles each containing a much smaller number of batteries reduces the risk of a chain reaction from batteries overheating, and the materials used in the ceiling tile can also be chosen, and the tile can be designed to eliminate the possibility of a fire breaking out.

1 1) There is a growing trend for people moving to live in the cities and they mainly live in apartments in high rise buildings and the "cabinet" style of battery storage system is not going to be as appealing to these high-rise apartment dwellers, as not many are going to want to have a reasonably big box of batteries bolted onto the wall in their living rooms, or bathrooms, or kitchens, or probably anywhere else in their apartments.

The foregoing objects, benefits and advantages of versions of the invention are illustrative of those which can be addressed by versions of the invention and not intended to be limiting or exhaustive of the possible advantages that can be realized. These and other advantages will be apparent from the description herein or can be learned from practicing versions of the invention, both as embodied herein as examples or as modified in view of any variations which may be apparent to those of ordinary skill in the art. Therefore, the invention resides in the novel devices, methods,

arrangements, combinations and improvements herein shown and described as examples and not limited therein.

ABBREVIATIONS USED

POSitA is used for a Person of Ordinary Skill in the Art.

FET is used for Field Effect Transistor

PV is used for Photovoltaic (cell) BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the present invention are illustrated as an example and are not limited by the figures of the accompanying drawings, in which like references may indicate similar elements and in which:

Figure 1 illustrates battery panels installed as ceiling tiles in suspension ceilings.

Figure 2 illustrates a single sheet paper battery.

Figure 3 illustrates four single sheet paper batteries connected in series to increase the voltage. Figure 4 shows 4 AAA 1.5V batteries connected in series.

Figure 5 illustrates eight single sheet paper batteries connected in series to increase the battery voltage eightfold.

Figure 6 illustrates four single sheet paper batteries connected in parallel to increase the amp-hour capacity rating.

Figure 7 illustrates four AAA 1.5V batteries connected in parallel.

Figure 8 illustrates a stack of four paper battery sheets in series inside a wall/ceiling battery tile. Figure 9 illustrates two stacks of paper battery sheets connected in parallel inside a wall/ceiling battery tile.

Figure 10 illustrates four battery tiles connected in series.

Figure 11 illustrates four battery tiles connected in parallel.

Figure 12 illustrates a single battery tile showing the external connectors.

Figure 13 shows typical banana plug and socket connectors.

Figure 14 illustrates four battery tiles connected in parallel using banana plug/sockets.

Figure 15 shows four 6V lead-acid batteries connected in parallel.

Figure 16 illustrates four battery tiles connected in series using banana plug/sockets.

Figure 17 shows four 6V lead-acid batteries connected in series.

Figure 18 illustrates a battery tile with two pairs of connectors.

Figure 19 illustrates series connections for battery tiles with dual connectors.

Figure 20 illustrates parallel connections for battery tiles with dual connectors.

Figure 21 illustrates a small setup of four rows of battery panels with eight tiles in each row.

Figure 22 shows the typical layout of surface mount ceiling tiles.

Figure 23 illustrates battery panels surface mounted as ceiling tiles. Figure 24 illustrates a single battery tile showing the internal wiring required to the four corner terminal connections

Figure 25 illustrates a single battery tile showing a top view of the required terminal layout.

Figure 26 shows the corner terminals for securing and connecting the battery tiles.

Figure 27 shows a method of securing the surface mount battery tiles.

Figure 28 shows a method of connecting the surface mount battery tiles together

Figure 29 illustrates four surface mount battery tiles connected in parallel

Figure 30 illustrates four surface mount battery tiles connected in series.

Figure 31 illustrates a method of connecting the surface mount battery tiles in rows and columns

Figure 32 is a diagram of a solar energy system for a residential building.

Figure 33 illustrates a method of connecting FETs across capacitor batteries in series.

Figure 34 illustrates a single battery tile, showing the base and cover.

Figure 35 illustrates a single battery tile, showing the base and cover in side elevation.

Figure 36 illustrates the snap fit joining of battery panel base and cover.

Figure 37 illustrates the location of Snap Fit Joints of Battery Panel Base and Cover.

Figure 38 illustrates the location of the snap fit joints when tiles are installed.

Figure 39 illustrates a single battery tile, with a low voltage LED downlight.

Figure 40 illustrates a single battery tile, with a low voltage LED light panel.

Figure 41 illustrates part of the charge controller functionality included in the battery tiles.

Figure 42 illustrates the battery module charge controller located inside a battery tile.

Figure 43 illustrates the battery module charge controller tile located at the end of each row.

Figure 44 Shows simpler wiring of the stacks of paper battery sheets inside a battery tile.

Figure 45 shows the connections to the external charge controller.

DRAWING COMPONENT INDEX

101 Battery Panel

102 External electrical connection to the tile.

103 Single-sheet paper battery.

104 Positive electrical connection to the paper battery.

105 Negative electrical connection to the paper battery.

106 Banana plug socket. 107 Banana plug.

108 Connecting wires

109 FET required for voltage balancing of paper sheet batteries

202 Holes for screw mounting

203 Screws for screw mounting

103 Single paper battery sheet

108 Wiring to stack of paper battery sheets

208 Base metal connection plate/terminal

209 Recess for inserting connector plate

214 Metal insert connector plate

300 Photovoltaic Solar Panel.

301 Battery Panel Cover

302 Battery Panel Base

315 LED downlight

316 LED lighting panel

317 External DC load

319 Battery Power Bank

320 DC-DC converter.

321 DC- AC power inverter.

322 Battery module.

323 Battery module charge controller.

324 External charge controller.

325 Bus bar inside battery tile.

326 Extra terminal for voltage input to battery module charge controller .

327 Extra terminal for voltage output from battery module charge controller

328 External wiring connection required between terminals 1 and 4. DESCRIPTION OF EMBODIMENTS

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the listed items. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well as the singular forms, unless the context clearly indicates otherwise. It will be further understood that the terms "comprising" and/or "comprises" where used in this application specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of other features, steps, operations, elements, and/or components.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one having ordinary skill in the art to which the invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure and will not be interpreted in an idealized or overly formal sense unless expressly defined herein.

The term "panel", as used herein, means a flat or curved, usually, but not necessarily, rectangular part, or piece of wood, metal, cloth, or other material, that forms, or is set into or onto, a larger surface such as a door, interior or exterior wall, floor or ceiling. The definition, as used herein, includes ceiling, wall and floor tiles.

In describing the invention, it will be understood that a number of techniques and steps are disclosed. Each of these has individual benefit and each can be used in conjunction with one or more, or in some cases all, of the other disclosed techniques. Accordingly, for the sake of clarity, this description shall refrain from repeating every possible combination of the individual steps in an unnecessary fashion. Nevertheless, the specification should be read with the understanding that such combinations are entirely within the scope of the invention.

The present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiments illustrated by the figures or descriptions below. The present invention will now be described by referencing the appended figures representing preferred embodiments. New building fixtures, such as low profile panels which may be installed in convenient locations such as, but not restricted to, walls and ceilings, in a building for the purpose of containing battery storage systems for renewable energy systems such as but not limited to solar power, is disclosed herein. The panels can be connected together electrically in different ways to configure the storage capacity and voltage output to match the requirements of the electrical system of the building.

Typically the battery storage is used to provide a DC voltage to an inverter circuit which then provides AC power for the building. Figure 32 shows one possible configuration for how the battery storage system of the present invention could be incorporated into such a solar energy system. The system has either one or a number of solar PV panels 300 connected to a charge controller 324 which connects to the battery storage 319. The charge controller also controls the discharge of the battery storage to power appliances and lighting in the building. This can be done via a DC-DC converter 320 for DC appliances and lights, or through an AC power inverter 321 to power AC devices.

The battery panels described in this invention could utilize any one of several current or new battery technologies, for example, but not restricted to, the paper batteries that have been developed at Stanford University in the USA. Paper batteries can also be purchased from PBC Tech, 165 Jordan Road, Troy NY 12180. These paper batteries are very suitable for use in wall and/or ceiling panels as they are made of thin sheets of paper that can be easily stacked and connected together in a large number of different ways to produce battery panels of higher voltage and/or higher amp-hour capacity ratings. Figure 2 illustrates a single sheet paper battery 103 with positive 104 and negative 105 connections to the paper battery.

A POSitA will understand that there will be a multitude of other batteries that may also be suitable for use in the present invention. For example, the super-capacitor batteries being developed by Supercapacitor Materials Ltd in England based on research done by the University of Surrey and University of Bristol. The batteries may also be manufactured using materials other than paper, such as but not limited to, different types of plastic which can also be used in the form of one or more thin sheets.

The paper battery sheet described in the preferred embodiment of the present invention is a flexible, ultra-thin energy storage device formed by combining graphene nanotubes with a conventional sheet of cellulose-based paper. However, at the present time, graphene nanotubes are expensive, and the use of commercial deployment of paper batteries will rely on the development of more inexpensive manufacturing techniques for graphene nanotubes. At the present time, using paper batteries, or similar, in the application described in the present invention may not be cost effective. But it is expected that inexpensive methods of manufacture will become available sometime in the very near future and much research is being conducted to this end. One of the aims of one current research project is to produce the paper batteries using a newspaper-type roller printer. This would make the manufacture of these batteries very cost effective.

There are many ways that battery panels could be installed in buildings, such as but not limited to, wall mounted panels that are presented as wall paintings, or wall and/or ceiling tiles with attractive designs that make them part of the decor of the room in which they are installed. Because they are light and low profile, the battery panels of the present invention could also be installed by laying them on top of the existing ceiling. However, without detracting from the potential for those, and many more possible applications, the preferred embodiment to be described first involves the use of battery panels installed in suspended ceilings. Suspended ceilings are seen to offer a very convenient way for the panels to be installed because the battery panels would simply and easily replace the normal ceiling tiles. This could be for new installations of a suspended ceiling, or where the tiles are being replaced in an existing suspended ceiling. The construction of a suspended ceiling is well known by those in the industry. Typically there is a ceiling grid which is usually hung from support wires that are secured to joists above, or part of the solid structure above. This grid is also usually supported by sitting on an L shaped molding fastened around the perimeter of the room. The frame members of the grid that carry most of the load of the ceiling are called main runners, and the ends of the main runners rest on the perimeter moldings and run the length of the room. Cross tees are installed across these runners spaced at intervals depending on the size of the tiles being installed. Other methods of installing the ceiling grid may also be used, and may be equally suitable for supporting the ceiling tiles. These methods will be well known to those skilled in the art.

Figure 1 illustrates how battery panels 101 in the form of ceiling tiles could be installed in place of the normal ceiling tiles. These will be referred to in the remainder of the description of the embodiments as battery tiles. The battery tiles illustrated in Figure 1 have two pairs of electrical connections 102, one at each end of the panel. The electrical connections between tiles can be made using a variety of different types of connectors. In the preferred embodiment being described for suspended ceilings, banana plugs and sockets have been used. Said connectors are very suitable for quick connect and disconnect, but, as it is not anticipated that the battery tiles will need to be connected and disconnected very often, screw terminal connectors and other types may be equally suitable and even more so in installations including others not involving suspended ceilings.

A POSitA will also understand that the actual voltage of an individual battery cell will depend on the technology and materials being used and other factors such as the size of the battery. Most supercapacitor battery cells have voltages between 2.5V and 4.0V. The present invention is able to utilize many different battery cell voltages including, but not limited to, that voltage range. For the purposes of simplifying the detailed explanations here, the single sheet paper battery used is assumed to have a voltage of 3.0 volts. In discussing how the batteries connect together, some comparisons with a standard household 1.5V AAA or AA battery are also made, but that does not imply the battery cells used are of that voltage.

Figure 3 illustrates four single sheet paper batteries 103 stacked on top of each other and connected in series. This method of connection increases the voltage fourfold, so if the individual batteries have a voltage of 3.0 volts, then the four batteries in series have a combined voltage of 12.0 volts. But the amp-hour capacity of the four batteries in series is the same as it is for a single battery. This series connection of four single sheet paper batteries produces a similar result as illustrated in Figure 4, where four standard AAA 1.5V batteries are shown connected in series to give 6.0 volts.

Figure 5 illustrates eight single sheet paper batteries 103 connected in series which has the effect of increasing the battery voltage eightfold, so the combined voltage, for a single cell voltage of 3.0 volts, is 24.0 volts. Again, the amp-hour capacity of the eight batteries in series is the same as it is for a single battery. A POSitA will understand that we can continue to connect additional single sheet paper batteries in series to achieve any higher voltage that we want, as long as that voltage is a multiple of the individual cell voltage.

A POSitA will understand that connecting certain types of batteries, including super-capacitor batteries, together in series like this, may require voltage balancing for each of the cells in series. Figure 5 show a FET 109 connected across the + and - terminals of the paper battery sheet on the top of the battery stack. Although not shown in the diagrams a POSitA will understand that one of these FETs may be required for each of the paper batteries when they are connected in series in the battery stack. Why this is required is explained in Reference 2 (see References at the end of this document)

Figure 6 illustrates four single sheet paper batteries 103 stacked on top of each other with the plus (+) 104 and minus (-) 105 terminals connected such that the battery sheets are connected in parallel. This method of connection does not increase the voltage of the connected batteries; instead it increases the amp-hour capacity of the four batteries in parallel fourfold. This method of connection does not require the connection of FETs across the plus (+) and minus (-) terminals of each paper battery as voltage balancing is not required when the battery sheets are connected together in parallel. The result of connecting four single sheet paper batteries in parallel is the same, as shown in Figure 7 which illustrates four AAA 1.5 V batteries connected in parallel. A POSitA will understand that we can continue to connect additional single sheet paper batteries in parallel to continue to achieve higher amp-hour capacity ratings.

Connecting the paper battery sheets in parallel within each battery stack, as shown in Figure 6, and then connecting the battery stacks in series may be seen to be the preferred method of connection because this is likely to reduce the number of FETs as they will only be required to be connected between the battery stacks when they are connected in series, and not between each paper battery sheet in each stack. There is likely to be fewer stacks of batteries in each battery tile than there are paper sheet batteries in each stack.

Figure 8 illustrates four paper battery sheets 103 stacked on top of each other, connected in series and embedded inside a battery tile 101. Again, additional single sheet paper batteries can be connected in series, inside the battery tile, to achieve any higher voltage that we require, as long as, it is a multiple of the individual cell voltage.

Papery battery sheets can be very small, some about the size of a big postage stamp. For the purpose of the present invention, the battery sheets are likely to be bigger, possibly the size of A5 or even A4 paper sheets. But they will still be smaller than the battery tiles of the present invention. Two of the standard sizes for ceiling tiles are 2 ft by 2 ft, and 2 ft by 4 ft and they are typically 0.5 inches thick. So, although this is not illustrated in any of the drawings, a POSitA will understand that it may be possible to stack many of the paper sheet batteries on top of each other. The exact number will depend on the exact dimensions of the tile, and the thickness of the paper sheet battery, but a total of 20 to 50 paper sheet batteries stacked on top of each other should be possible. In addition, a POSitA will understand that it is possible to have more than one such stacks of paper sheet batteries placed alongside each other and embedded inside the battery tile, and that there is a large number of combinations of different ways that these stacks of single sheet paper batteries could be connected, both in series and in parallel, to achieve an equally large number of different voltages and amp-hour capacity ratings possible for a single battery tile. Figure 9 shows two stacks of paper batteries connected in parallel inside a wall/ceiling battery tile. In this case, the paper batteries themselves are connected in series to achieve a higher voltage, and the stacks are connected in parallel to achieve a higher amp-hour capacity rating.

Although not shown in any of the drawings, a POSiTa will understand that the connections could have been made the other way around. The paper battery sheets themselves could be connected in parallel to achieve a higher amp-hour capacity rating for each stack, and the stacks could have been connected in series to achieve a higher voltage for the battery tile.

In Figure 24, the paper batteries in each stack are all connected in parallel and the plus (+) and minus (-) terminals of each stack are connected so that the stacks are also connected in parallel. This results in the highest possible amp-hour capacity rating for the battery tile, but the voltage of the battery tile will be that of a single paper sheet battery, typically 2.5 to 4.0 volts. It also means that voltage balancing is not required between each battery in the stacks or between the stacks. In order to achieve a suitable voltage to power an inverter, the paper batteries and/or the battery panels could be connected together in series within the rows of an installation, as shown in Figures 29 and 30. The installer then still has the option of connecting the rows together in series to achieve an even higher voltage, or to connect the rows in parallel to achieve a higher amp-hour capacity. There is a multitude of ways that the battery tiles can be made. They require to be constructed such that the stacks of paper batteries are enclosed inside, and to permit convenient and effective electrical connections externally between the battery panels. The battery tile has a top, a bottom, and four sides. Although not limited to this, the battery tiles may be hollow, with the paper batteries 103 placed in one or more stacks inside the cavity of the hollow tile, and electrically connected from the paper battery sheet terminals 104 and 105 to the electrical connectors 102, of several different possible types, that are made available on the outside of the battery tile, so the tiles can then be electrically connected together. The external walls of the battery tiles can be made of many different materials, not restricted to, but including PVC laminate, aluminum sheet, leather, cardboard, and others. The battery tile may also be molded with the molding material encapsulating the battery stacks inside.

For the preferred embodiments of the present invention, the size of the battery tiles is 2 ft by 2 ft, or 2 ft by 4 ft, so they can act as direct replacement for two of the industry standard size ceiling tiles. But the battery tiles are not restricted to these dimensions. The thickness can be varied to suit the number and size of the batteries enclosed within, but for the preferred embodiments of the present invention a thickness of 0.5 inches to 1 inches thick is suitable for the construction of the battery tiles. One of the aims of construction is that they preferably will be light weight, and preferably low profile, simply to reduce the weight of the battery storage system being assembled on, or in, the ceiling or wall.

The battery tile may also be filled with other material around the battery stacks. There are many different filler materials that may be used to give the tile a little more strength, to provide acoustic and thermal insulation, and to help to contain any problems from overheating of batteries. These include any of the materials currently used in ceiling tiles, not restricted to, but including mineral fiber (wool), gypsum (plaster board), acoustic fiberglass wool, calcium silicate and others.

Figure 10 illustrates four battery tiles 101 connected in series and Figure 11 illustrates four battery tiles 101 connected in parallel. In both cases, these four tiles would be installed alongside each other in one row of the ceiling tiles. The same situation exists in connecting the battery tiles together, as exists in connecting the single sheet paper batteries together, in that there is a large number of combinations of ways in which the battery tiles can be connected together. If you need a higher voltage than the individual battery tiles provide then you would connect the battery tiles in series to increase the voltage. If the battery tile voltage is already exactly, or close to, what you need, then you could connect the battery tiles in parallel to increase the amp-hour capacity rating of the connected battery tiles.

In regard to the method of connections between battery tiles, there will be many ways in which this can be accomplished. In the preferred embodiment described for the present invention, for suspended ceilings, electrical connection terminals or sockets 102 on the top of the battery tiles represents a convenient way of making the wired connections 108 between tiles. The use of screw terminals is one way, among several, that this can be accomplished. In the preferred embodiment, banana plugs and sockets are used to make it easy to connect and disconnect tiles, but considering that this is not likely to happen very often after the initial installation, some installers may still prefer to use screw terminal connections, or other connection types, and cut the wires to the exact length required by each connection. To keep resistances of connections as small as possible, and the same for identical connections, the connecting leads 108 should be as short as possible, and the same length for identical connections. Figure 12 illustrates a single battery tile 101 with one pair of connectors 102 for the plus and minus terminals of the battery. Figure 13 depicts banana plug 107 and socket 106 connectors as a suitable way of making the connections between battery tiles.

Banana plug connectors, on the ends of wires 108, plug into the sockets and the electrical connection is made through the connected wires. Figure 14 illustrates four battery tiles 101 connected in parallel using the banana plug/socket wiring. If each battery tile has a voltage of 6V, then the result you get is as depicted in Figure 15, which shows four 6V lead-acid batteries connected in parallel. The voltage is still 6V, but the amp-hour capacity has been increased fourfold.

Where the connections between tiles is made using connecting wires, the gauge of the wire should be chosen to ensure that the maximum current expected to be flowing in the wire can be easily accommodated and involves an absolute minimum voltage drop across the wire as a result of the current flowing through it. The connection should be thought of as an electrical bus bar.

Figure 16 illustrates four battery tiles 101 connected in series using the banana plug/socket wiring. If each battery tile has a voltage of 6V, then the result you get is as depicted in Figure 17, which shows four 6V lead-acid batteries connected in series for a total voltage of 24 volts.

In the preferred embodiment dual connectors would be used on each battery tile to simplify the wiring connection between tiles. The dual plus and minus terminal connectors are wired together inside the battery tile, plus connected to plus, minus connected to minus, as illustrated in Fig 18.

Figure 19 illustrates the result you would get with series connections of four battery tiles using the dual connectors, and how they should be connected. The wiring between tiles is very short in this case, with only a requirement for one long lead or bus bar running from one end of the four panels to the other end, and even this may not be necessary in some installations. If the battery tiles in one row are connected in parallel then only very short leads between each adjacent pair of tiles is required, as shown in Fig 20.

Using battery tiles like this allows the installer to configure the layout and wiring connection of the battery tiles to provide the voltage and amp-hour rating required by the building. In a preferred embodiment, battery tiles with a voltage of 3 volts or 6 volts would be most suitable to provide voltages of 12, 24 or 48 volts to power the inverter circuit, with the maximum possible amp-hour capacity rating. As previously explained, if the paper battery sheet has a voltage of 3 volts, internally stacks of paper battery sheets may be connected both in series, if required to achieve the higher voltage, and also in parallel to provide a higher amp-hour capacity rating.

If the battery tile has a voltage of 3 volts, in order to provide voltage for a 24 volt inverter, eight of the battery tiles would be connected in series in one row, the same as illustrated in Figure 19, but with eight battery tiles instead of just four. Then more identical rows of battery tiles would be installed. Each row then effectively becomes a 24 volt battery. The plus and minus battery terminal connections at the ends of each row are now connected together in parallel to increase the amp-hour capacity of the battery storage system. The number of rows required would be determined by the amp-hour capacity requirement for the overall battery storage system.

Figure 21 illustrates a small setup of four rows of battery tiles with eight tiles in each row. Each battery tile has a voltage of 3 volts and a capacity rating of 20 amp-hours (Ah). With eight battery tiles in each row connected in series, each row produces 24 volts at 20 Ah. Connecting the four rows together in parallel provides a voltage of 24 volts at 80 Ah. Adding more rows increases the amp-hour rating proportionally. A POSitA will understand that this is just one simple example of many different possible combinations of ways in which the battery tiles can be connected together. The voltage and amp-hour capacity of each battery tile, the number of batteries connected in series in each row, and the number of rows connected together in parallel, are just some of the variables that can be changed from one installation to another, resulting in battery storage systems that can have different overall voltage and amp-hour capacities, as required by the electrical system of the building.

The foregoing description is the preferred embodiment for suspended ceilings. A preferred embodiment for surface mounting tiles on walls and ceilings will now be described. While the present disclosure provides a detailed description relating mainly to ceiling tiles it will be understood by a POSitA that the same would also apply to tiles that are surface mounted on other surfaces, such as but not limited to, the walls of a building. Figure 22 shows the typical layout of surface mounted ceiling tiles. It comprises a matrix of square or rectangular ceiling tiles which are normally attached to a supporting surface above them such as, but not limited to, a pre-existing ceiling.

Figure 23 illustrates how battery tiles 101 in the form of ceiling tiles could be installed by screwing them to the supporting surface. A POSitA will understand that there will be a multitude of methods for securing the tiles including gluing them to the supporting surface, but in the preferred embodiment of the present invention for surface mounted tiles, four screws 203 are inserted through holes 202 at each corner of the tile. Although not shown in this drawing each hole may have a plug to cover the hole after the screw has been secured to the supporting surface. Although not essential, but for aesthetic reasons, the plugs should fill in and complete whatever pattern is on the rest of the tile.

It will be advantageous for the battery tiles to be installed in such a way that they can be removed individually without having to disassemble or remove other battery tiles around them. This could be necessary to repair a broken tile or to replace one or more that are malfunctioning. The method of tile construction and installation of this preferred embodiment allows for this to be done.

In the preferred embodiment for surface mounted ceiling tile batteries described for the present invention, Figure 24 shows a single battery tile with the internal wiring required to connect the battery stacks to four terminal connections 208. Either fewer, or more than, four terminals could also have been used. Although they may have been located otherwise, these have been placed in the corners of each tile. Two of the terminals, 2 and 4, are positive (+) and the other two terminals, 1 and 3, are negative (-). The terminals can be any shape, but in the preferred embodiment described they are square with a circular hole in the centre.

Figure 25 shows a top view of the layout of the terminal connectors 208 in each corner, and also shows how two FETs 109 could be installed in each tile to provide voltage balancing for the battery tiles when the tiles are being connected together in series. The FETs can be a standard component included in every tile. However, by design, they do not become involved in the connections when the tiles are connected in parallel.

The terminals serve two purposes. The first is to allow the tile to be screwed to the supporting surface above the ceiling tile, or behind in the case of a wall tile. The second is to provide a simple method of making the electrical connection between tiles. If, for a particular installation, there is no electrical connection required to be made to one or more of the terminals in a tile, then those terminals simply serve to allow that corner of the tile to be screwed to the supporting surface above. This is shown in both Figure 27 and Figure 28 where the screw 203 goes through the terminal connection 208.

The terminal 208 in each corner is located at the back of the tile as shown in Figure 26 where the orientation of the tile, as shown, is upside down for a ceiling tile. The back of the tile is the tile surface that will be surface mounted against the ceiling or wall. For mounting on the ceiling, the tile as shown in Figures 27, 28 and 29 would be inverted from that shown.

The metal terminal connector 208 is embedded in the tile, and in front of said metal terminal connector (on top as shown in Figure 26) there is a slot or recess 209 in the tile, the same size as the terminal connection. This slot will be below the terminal connection when the tile shown in Figure 26 is inverted for installation as a ceiling tile. The slot allows for a connector plate 214 to be inserted into the tile and also thereafter into the tile alongside it whenever an electrical connection is required between those terminals of the two tiles. Half of the connector plate goes into the slot 209 in one tile and the other half goes into the slot in the adjacent tile. The connector plate 214 is shown in Figure 28. Both the metal terminal connector 208 and the connector plate 214 must be made of electrically conductive material, such as but not limited to copper metal. When the connector plate has been inserted then the screw 203 goes through both the connector plate 214 and the terminal connection 208. When tightened, the screw will press these together making a good electrical connection between them.

This represents a convenient way of making the electrical connections between tiles. Moreover it keeps the connections as short as possible and the connections will all be the same length. This keeps the resistances of the connections as small as possible, and the same for identical connections. Figure 29 illustrates four battery tiles 101 connected in parallel using this method of connection. The connections are shown as curved links just to emphasize the connection, but they are in fact the short, straight connector plates 214 described before and illustrated in Figure 28. Note that, for a parallel connection, each alternate battery panel is turned at 90 degrees anti-clockwise to setup the corner battery terminals plus (+) to plus (+) and minus (-) to minus (-). If each battery panel has a voltage of 6V, then the result you get is the same as depicted in Figure 15, which shows four 6V lead-acid batteries connected in parallel. Figure 30 illustrates four battery tiles 101 connected in series using this method of connection. Note that in this case all of the battery tiles are orientated the same way, to setup the corner battery terminals plus (+) to minus (-). If each battery panel has a voltage of 6V, then the result you get is as depicted in Figure 17, which shows four 6V lead-acid batteries connected in series for a total voltage of 24 volts.

Using battery tiles like this allows the installer to configure the layout and wiring connection of the battery tiles to provide the voltage and amp-hour rating required by the electrical site. In a preferred embodiment, battery tiles with a voltage of 3 volts or 6 volts would be most suitable to provide voltages of 12, 24 or 48 volts to power an inverter circuit or a DC-DC converter, with the maximum possible amp-hour capacity rating. As previously explained herein, if the battery tile has a voltage of 3 volts, internally stacks of paper battery sheets would be connected in parallel to provide a higher amp-hour capacity rating. In order to provide a voltage of 24 volts for an inverter or DC-DC converter, eight of the battery tiles would be connected in series in one row of the ceiling tiles, the same as illustrated in Figure 30, but with eight battery tiles instead of just four. Then more identical rows of battery panels would be installed. Each row then effectively becomes a 24 volt battery. The plus and minus battery terminal connections at the ends of each row are now connected together in parallel to increase the amp-hour capacity of the battery storage system. The number of rows required would be determined by the amp-hour capacity requirement for the overall battery storage system.

Figure 31 shows what might be a small part of a typical installation. Three rows of battery tiles are shown connected in parallel using the connector plates 214 as the method of connection. The tiles in each row are connected in series using the same connector plates. All the installer has to do is to change the orientation of adjacent tiles to change the connection from parallel to series. All of the connections between tiles are short and of the same resistance, and the resistance will be very low.

A POSiTA will also understand that all of the tiles installed on the walls and/or ceilings do not have to be battery tiles. The manufacturer of the tiles could also make matching tiles that do not have any batteries inside, and these can also be included as part of any installation. This may be utilized in installations where the required voltage and amp-hour capacity rating of the system has already been achieved with fewer tiles than are needed for the coverage of the ceiling or wall of the installation. Or alternatively battery tiles could be used for the extra coverage required, but without electrical connection to any of the other battery tiles in the battery storage system.

The battery tiles could have electrical appliances such as, but not limited to, low DC voltage LED lights fitted directly to the panels so that the LED lights are powered directly from the battery tile. This would be very appropriate when the battery tiles were being installed as ceiling tiles. Figure 39 shows a single battery tile, with a low voltage LED downlight 315, and Figure 40 shows a single battery tile, with a low voltage LED light panel 316.

In some embodiments of the invention it will be advantageous to be able to have a removable cover on the battery tiles which may also function as the decorative top of the tile. This would make it easier to install the tile, to make additional electrical connections within and between tiles, and to perform maintenance and troubleshooting services. One possible preferred embodiment which achieves these objectives will now be described.

For this preferred embodiment, the battery tiles are constructed in two main parts. The first is a base 302 which consists of a flat bottom and four walls which are used to enclose the contents of the battery tile, with the contents being firmly attached to this base. The second is a cover 301 to fully enclose the contents of the battery tile and to facilitate a multitude of different colors, materials and surface effects primarily for the appearance of the face of the battery tiles. Figure 34 shows a single battery tile, showing the base 302 and cover 301. It will be understood that this battery tile will be inverted when installed on the ceiling such that the base is attached to the ceiling.

There are a multitude of ways the base and cover can be fitted together, but for this embodiment of the present invention, the battery tiles are made of molded plastic and are designed such that the cover is a snap fit into the base of the battery tile. The base is hollow, being substantially just four side walls and a back wall. Figure 35 shows the side elevation of a single battery tile, showing how the base and cover fit together. Figure 36 shows one of many different methods that could be used for the snap fit joining of the battery tile base and cover. The molded plastic cover could use the entire edge of the tile cover to provide snap fit inserts into the tile base, and many other alternatives are possible, but for this embodiment of the present invention, the cover has snap fit joints 307 at four locations and these are shown in Figure 37. These locations have been chosen so that the battery tile cover can be inserted in any orientation. This will be advantageous when it comes to matching similar patterns on adjacent tiles, especially when the base itself may be rotated through 90 degrees to change the electrical connection between two adjacent tiles from serial to parallel. Figure 38 shows the location of these snap fit joints 307 when the tiles are installed alongside each other.

For solar energy systems, useable solar energy is available, at best, for only a quarter of the day and the charging of the battery bank should occur during that period. A charge controller is employed to ensure that the battery bank gets fully charged, and isn't damaged by over-charging, or charging too fast, or by overheating. The controller also has to prevent the battery from discharging through the PV panel at night.

Many different charging and termination schemes have been developed for different types of batteries and different system configurations. One example of a solar energy system configuration is shown in Figure 32. The diagram would be similar for other renewable energy systems which may use, for example, wind turbines as the source of energy. While this diagram only shows one solar panel 300 a POSiTA will understand that there will normally be several or many solar panels connected together, and that there is a multitude of ways that this can be done.

Regardless of the overall system configuration, the battery bank is involved in two main functions:

( 1 ) charging of the battery bank during sunlight hours of the day, and

(2) providing power to AC and DC lighting and appliances in the building when the solar panel is unable to.

To facilitate this it would be advantageous if at least part of the charge controller functionality is incorporated into the battery tiles. A POSiTA will understand that there are many different ways that this can be accomplished, and the diagram in Figure 41 illustrates just one such method.

The diagram in Figure 41 shows the battery modules 322, the battery module charge controller 323, an external charge controller 324, one or more solar panels 300, and a DC load 317.

The battery modules 322 shown in the diagram can be either individual battery tiles, or they could be any number of battery tiles connected together in a multitude of different ways, such as the single row of battery tiles as shown in Figures 29 and 30.

There are many circuits that can be found on the internet for charge controllers capable of performing the functions required of the battery module charge controller 323 and the external charge controller 324, and there are many companies around the world already making and selling suitable charge controllers for these applications. The battery module charge controller 323 should be designed or chosen to match the charging and discharging requirements of the types of batteries that are used in the battery panels.

For the preferred embodiment of the present invention, the battery module charge controller 323 is built into the last battery tile at the end of a row of battery tiles which are connected in series. This reduces the cost of the system overall, because the battery module charge controller is not included in every tile, and it also simplifies the required connections for the tiles that do not have it, which means for most of the battery tiles.

Batteries that are based on capacitor technology do not charge and discharge the same as chemical batteries such as lead-acid batteries or lithium batteries. During discharge, the voltage drops linearly. and it is possible to discharge a capacitor type battery to almost zero volts, without damaging the battery. To maintain the level of power being delivered by the battery, a DC-DC convertor is often employed to draw higher current with the decreasing voltage.

When it comes time to recharge a capacitor type battery, if the capacitor battery voltage is close to zero, it will appear like a short circuit to the battery charger and the current, if not controlled, will be very high. The voltage increases linearly during a constant current charge. It is not the voltage that determines how quickly the capacitor battery charges; it is the size of the current. The capacitor battery is not damaged by fast charging, so the benefit of having a high charging current is faster charge times. When the capacitor battery is full, the current drops by default and the charging stops. Having the battery module charge controller 323 at the end of each row also means that the battery tiles in this row can be charged separately from the other rows of battery tiles in the battery bank. This would be a major advantage for the capacitor types of batteries that are part of the preferred embodiment of the present invention. The current rating of the charging circuit can be reduced significantly by charging one row at a time. If there are ten rows of battery panels in the battery bank, the required charging current will be reduced by a factor of ten, compared to charging all of the rows of battery panels together.

Capacitor-type batteries can normally be re-charged very quickly, much faster than most other types of batteries, and so charging each row, one at a time, is not likely to mean that there is not enough time during the sunlight hours of the day to re-charge all of the rows of battery tiles.

For the preferred embodiment of the present invention, the battery module charge controller 323 would be required to perform these functions: (1) Control the current used to charge the battery tiles. This is especially important if the battery voltage is very low, and this is likely to be the case on many occasions because capacitor type batteries are not damaged, like most other battery types, if they are fully discharged to zero volts.

(2) To make sure that the battery tiles are not over-charged. This means the charging should be terminated before reaching the voltage rating of the capacitors making up the batteries.

Figure 42 shows the battery module charge controller installed inside a battery tile. Although there are other ways of charging the battery tiles in this row, in this embodiment, the battery module charge controller will charge all of the battery tiles in series at the same time. Voltage balancing of the battery tiles would be achieved by FETs, or other cell balancing circuits, connected across each battery tile, as heretofore explained

As shown in Figure 42, inside this tile, the positive of the paper batteries connect directly to the charge controller, and the negative of the paper batteries connect to the positive of the previous tile via terminal 1. These are internal connections. The charge controller also connects to two sets of external connections. Extra terminals 326 and 327 have been provided for this. One pair of terminals (2 and 5 in Figure 42) is for connection to an external power supply to allow the charge controller 323 to charge the batteries inside this battery tile and all of the other battery tiles in this row. The other pair of terminals (3 and 6) is for delivering a voltage from the batteries in this row to an external circuit.

In some configurations it may be advantageous to have a battery charge controller module in every battery tile. But for the preferred embodiment of the present invention, the battery module charge controller would only be installed in the battery tile at the end of each row of battery tiles.

Figure 43 illustrates four battery tiles 101 connected in series using the same method of connection as illustrated in Figures 30 and 31 but with the battery module charge controller 323 built into the last battery tile at the end of each row of battery tiles. There are many different ways that the battery module charge controller and the external charge controller can be designed to work together, with all of the functions required of a suitable battery charge controller being shared between the two of them.

For the preferred embodiment of the present invention, the battery module charge controller 323 has been placed at the end of each row, and this means there is no longer any need to connect the individual rows of battery tiles together directly to achieve a parallel connection. This can be done in the external charge controller. As shown in Figure 43, an external wiring connection 328 between terminals 1 and 4 is required on the first battery tile in each row. The bus bar connection 325 between terminals 3 and 4, inside the battery tile, and the links between tiles, makes a connection from the negative terminal of the first battery tile all the way through to the external charge controller 324. The use of a bus bar type of connection inside the battery tile minimizes the voltage drop due to the low resistance of the connection. All other wiring connections must be made with wire gauge sufficient to handle the current transferred inside the battery tile, with a minimum drop in voltage. This is necessary for the battery tiles when they are connected in series.

This method of connection is suitable for battery tiles connected in series within a row so all of the battery tiles in the battery bank are now oriented the same way. They do not need to be rotated in any of the rows to achieve parallel connections between battery tiles. As a result, the internal wiring of the stacks of paper battery sheets inside the battery tiles can be a little simpler, as shown in Figure 44.

The external charge controller 324 is connected to the battery module charge controllers at the end of each row and to the array of solar panels. There are two sets of connections to each battery module charge controller, shown as connection A and connection B in Figure 45. Connection A is to transfer the voltage from the array of solar panels through to the battery bank for charging the batteries. Connection B is to deliver power from the battery panels to the building's power circuits, via DC-DC converters or AC inverters if necessary.

The battery module charge controller 323 manages the charging for each row of batteries, but the external charge controller 324 determines how the voltages from the solar panel are connected to each of the battery module charge controllers. A POSiTA will understand that there are various ways that this can be done. For example, the outputs of each solar panels can be connected together either in series or in parallel, and this voltage can be switched through to the battery module charge controllers of each row one at a time, for all of the battery tiles in each row to be charged, one row at a time. An alternate method would be for the external charge controller to be able to connect different banks of solar panels through to all of the battery module charge controllers, so that all of the rows of batteries are charged at the same time. The external charge controller is best designed as an intelligent controller, based on a microcontroller integrated circuit, and the different options for how the rows of batteries are charged could be selected by the user, based on information collected from the system regarding the previous performance of charging the batteries using the different charging methods provided by the external charge controller.

The external charge controller 324 is also connected to the DC electrical loads via a DC-DC converter 320, and it supplies power to the AC circuits in the house via a DC-AC power inverter 321. A POSiTA will understand that there are a multitude of different ways in which this can be done. For example, all of the rows of battery panels may be connected together in parallel by the external charge controller, with that DC voltage then being passed on to the DC-DC converter 320 and the DC-AC power inverter 321. Alternatively, some rows of the battery bank may be connected to provide power to certain electrical circuits while others are connected to provide power to different electrical circuits. There also may be more than one DC-DC converter and more than one DC-AC power inverter attached to the external charge controller to facilitate this. The connections of the different rows of battery panels to the external DC and AC circuits may also be determined by the external charge controller based on a user programmable system of priority for the electrical circuits. The external charge controller 324 determines when the solar panels are supplying enough voltage and power to be connected directly to the load circuits, and which loads can be driven directly by the power coming from the solar panels.

If the external charge controller determines that there is insufficient voltage or power coming from the solar panels, then it determines if there is enough voltage stored in the battery bank to switch that through to the DC-DC converter 320 and/or to the DC- AC power inverter 321.

There also may be times when it is best to have some of the load circuits powered by the voltage coming directly from the solar panels, while some of the other circuits will get their power from the battery bank. There may also be times when the external charge controller determines that there is insufficient voltage or power coming from either the solar panels or the battery bank, and it may then disconnect the load circuits. Before it gets to that stage of shutting down all of the building's power circuits, the external charge controller may decide to disconnect everything except for a low power DC emergency lighting system. Or the external charge controller may connect the external circuits to the normal building powers supply coming from the local electricity grid.

A POSiTA will understand that this is just one of many possible methods and configurations for a renewable energy power system. RFERENCES

1. Transparent solar technology, see

http://msutodav.msu.edu/news/2017/transparent-solar-techn ologv-represents-wave-of-the-future/

2. A New Method of Balancing Supercapacitors in a Series Stack Using MOSFETs, see www.aldinc.com. search: sab mosfet.