FIELD OF THE INVENTION

The invention relates to a method, as defined in the preamble of claim 1, and, to an apparatus as defined in the preamble of claim 7, for producing energy. In this application, the method and apparatus according to the invention will also be commonly referred to as the solution according to the invention. The invention utilizes a change of the volume of gas/air and the resulting difference of buoyancy in a liquid/water .

BACKGROUND OF THE INVENTION AND PROBLEMS RELATED TO THE PRIOR ART

Our current manner/ standard of living is enabled by the low price and availability of energy but inexpensive energy solu- tions always suffer from the problem of exploitation of various degrees of nature and of pollution of nature. Coal is extracted from the ground in large mines with a significant effect on the environment. Coil burning induces considerable carbon di oxide emissions which have proved to be a reason for the cli- mate change. Oil drilling from the ground has been increasing as it has been necessary to find new deposits, due to the old ones running dry. The process of extracting oil from the sea bed by drilling is expensive and involves a risk of an envi ronmental disaster. The drawbacks of fossil energy sources include their limited availability, environmental destruction and air pollution. Therefore, it is natural to look for new, less polluting and renewable solutions for producing energy.

As is known, these less polluting and renewable solutions in- elude wind power and solar power, for example. However, they both suffer from the problem of being dependent on weather conditions. Wind power and solar power apparatuss require wind and sunlight to work, respectively. Consequently, the power apparatuss cannot uninterruptedly be used to their maximum capacity. Besides, the wind and solar power apparatuss take up a lot of ground area. Neither is it possible to place windmills close to residential areas because their noise disturbs peo ple .

US 2006/017292 A1 discloses a solution for producing energy by means of two floating bodies positioned in a liquid, by ad- justing the buoyancy of the floating bodies. However, this solution is much more complicated than the solution according to the present invention.

OBJECTIVE OF THE INVENTION

The objective of the invention is to provide a method and an apparatus allowing clean and renewable energy to be produced, independently of conditions, such as weather conditions, space limitations, sunlight, hour of day, or other variables. The method according to the invention is characterized in what is set forth in the preamble of claim 1. Correspondingly, the apparatus according to the invention is characterized in what is set forth in the preamble of claim 7. Other embodiments of the invention are characterized in what is set forth in the rest of the claims .

DESCRIPTION OF THE INVENTION

The method according to the invention produces energy by means of two interconnected underwater movable bodies acting verti cally in a liquid, such as in water in a sea area. The movable bodies are connected to each other by some sort of transmission means, such as a braid similar to a wire rope, a rope, a strap or some other means suitable for the purpose. The transmission means serves for transmitting the kinetic energy of the movable bodies to an energy production apparatus connected between the movable bodies. The movable bodies mainly move in phase oppo sition to each other, restricted by the transmission means, and, therefore, are moved alternately up and down by buoyancy and gravity. The movement of up and down of the movable bodies is controlled by altering the buoyancy of the movable bodies, by adjusting the amount of a gas and liquid, such as air and water, flowing through valves provided therein.

ADVANTAGES OF THE INVENTION

An advantage of the solution according to the invention is it allows energy to be produced in an environmentally friendly way. Another advantage is that the solution is not dependent on weather conditions, such as wind or sunlight. Another ad vantage is that the energy production apparatus can be placed underwater, such as undersea, far offshore, where it does not take up ground area or disturb the water area close to the shore. Neither does the apparatus cause disturbing noise, or any other, such as visual, disturbance to people. Another ad vantage is that the apparatus according to the invention can also be placed on dry land, in an old mine filled with water, or the like.

LIST OF FIGURES In the following, the invention will be described in detail by means of one embodiment, with reference to the accompanying drawings wherein

Figure 1 is a schematic view of the apparatus according to the invention, in a direction change state, and

Figure 2 is a schematic view of the apparatus according to the invention, in an energy production state. DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows the apparatus according to the invention in a direction change state. The apparatus comprises two movable bodies 2, connected to each other by a transmission means 12, such as a rope, braid, strap or some other means suitable for the purpose. The transmission means 12 is adapted to transmit the kinetic energy of the movable bodies 2 to an energy pro duction apparatus 3, such as an electric generator. A compres sor 4 and a reverse pressure tank 4A are connected to the energy production apparatus 3. The reserve pressure tank 4A is adapted to be filled by the compressor 4 which is driven by the energy production apparatus 3. The compressor 4 can also be driven, or partly driven, by some other source of energy. The compressor 4 is also adapted to fill the reserve pressure tank 4A when the movable bodies 2 are not at their top dead centers. The compressor 4 is adapted to work as continuously as possible, filling the reserve pressure tank 4A.

In this exemplifying embodiment, the movable bodies 2 are cu boid-shaped containers made out of standard sea containers, for example. The movable bodies 2 comprise pressure tanks 5 provided with pressure adjusting valves 10, internal spaces, i.e. buoyancy adjusting spaces 8 of the movable bodies, and buoyancy adjusting valves 6, 7 connected thereto.

The movable bodies 2 are attached to a support structure 11 comprising vertical guides 11A adapted to guide the movable bodies as they move vertically up and down.

The movable bodies alternate between a direction change state and an energy production state. In the situation shown in Figure 1, the movable bodies are in the direction change state, the first and the second movable body being at their bottom and top dead centers, respectively. The buoyancy adjusting space 8 of the first movable body is filled with water and the pressure adjusting valve 10 is closed. In the direction change state, the movable bodies 2 are substantially stationary for the du ration of the filling of the pressure tank of the movable body that is at its top dead center. The first movable body shifts from the direction change state to the energy production state when gas discharged through the pressure adjusting valve 10 displaces the liquid in the buoyancy adjusting space 8, inducing a sufficient buoyancy, and thereby, an upward movement, of the movable body. The valves 6, 7 of the second movable body are closed and the reserve pressure tank 4A is connected to the pressure tank 5 which is adapted to be filled with pressurized gas, such pressurized air, from the reserve pressure tank 4A. The pressure tank 5 is adapted to be filled with an amount of gas sufficient to lift the movable body 2 from its bottom dead center to its top dead center. For this purpose, the apparatus comprises measuring and controlling means for measuring the pressure of the gas contained in the pressure tank 5 and for controlling the amount filled therein. Once the pressure tank 5 has been filled up to a desired pressure, the apparatus is adapted to shift to the energy production state where the valves 6, 7 of the movable body 2 are adapted to open, and, thereby, to decrease the buoyancy of the movable body 2 by letting gas out of the buoyancy adjusting space 8, through the valve 7, and liquid for replacing it, into the buoyancy adjusting space 8 through the valve 6. The first movable body 2 is shifted, at its bottom dead center, into the energy production state by arranging the buoyancy adjusting space 8 to increase the buoy ancy of the movable body by letting gas out of the pressure tank into buoyancy adjusting space 8, through the pressure adjusting valve 10, and liquid out of the buoyancy adjusting space 8, through the valve 6. Figure 2 shows the apparatus according to the invention in the energy production state. In the situation shown in Figure 2, the first movable body moves upwards while the second movable body moves downwards. The buoyancy of the movable bodies 2 is adapted to be adjustable by means of the amount of gas and water contained in the buoyancy adjusting spaces 8. In the situation shown in Figure 2, liguid is discharged through the valve 6 provided at the bottom of the first movable body as the pressure tank 5 supplies gas into the buoyancy adjusting space 8 through the opened pressure tank valve 10. This increases the gas volume in the buoyancy adjusting space 8, resulting in an increase in the buoyancy as well. The second movable body loses its buoyancy, with the valves 6 and 7 provided therein opened and with liquid flowing into the buoyancy adjusting space 8 through the valve 6 and with gas flowing out of the buoyancy adjusting space through the valve 7. As the movable bodies move, the transmission means 12 trans- mits the kinetic energy of the movable bodies to the energy production apparatus 3 which is an electric generator, a hy draulic pump, a compressor or some other apparatus suitable for the purpose, for example. When shifting into the energy produc tion state, the buoyancy adjusting space 8 of the second movable body, which starts to move downwards, is adapted to be filled with liquid as rapidly as possible.

The method according to the invention produces energy by al tering the buoyancy of the movable bodies 2 by means of the amount of gas and liquid contained in the buoyancy adjusting space, with the result that the movable bodies move vertically within the liquid, the kinetic energy generated by this movement then being recovered by the energy production apparatus. The method has two continuously alternating operating states, the direction change state where the movable body can be at its top dead center or its bottom dead center, and the energy production state where the movable body is moving either up or down. How ever, the movable bodies can stop while the direction change state and the energy production state are shifted.

As the movable body 2 is at its top dead center in the direction change state, its pressure tank 5 is supplied an amount of gas sufficient to fill the buoyancy adjusting space 8 with gas, with the movable body 2 at its top dead center. The gas is fed into the pressure tank 5 by the compressor 4 or from the reserve pressure tank 4A. At the top dead center, shifting into the energy production state is carried out by opening the valves 6 and 7 in order to decrease the buoyancy of the movable body 2, and, thereafter, by filling the buoyancy adjusting space 8 with a liquid, such as water. As gas is discharged from the buoyancy adjusting space 8, the buoyancy of the movable body decreases and the movable body 2 sinks downwards and the transmission means 12 connected thereto transmits the kinetic energy gener ated by the sinking down of the movable body 2 to the energy production apparatus 3. After reaching its bottom dead center, the movable body 2 is shifted back into the direction change state where the valve 7 is closed. The movable body 2 is shifted from the direction change state back to the energy production state by increasing the buoyancy of the movable body 2 by means of a discharge of liquid from the buoyancy adjusting space 8. The liquid is discharged from the buoyancy adjusting space 8 through the valve 6 while the pressure tank 5 supplies gas, through the valve 10, to replace the discharged liquid. The increased gas volume in the buoyancy adjusting space 8 increases the buoyancy of the movable body 2 and causes the movable body 2 to move upwards, towards its top dead center. At the top dead center, the process of the movable body 2 restarts from the beginning and the pressure tank 5 is filled again with a suf ficient amount of gas, by the compressor 4 or from the reserve pressure tank 4A.

In the solution according to the invention, the movable bodies 2 act independently but within limits set by the transmission means. The apparatus according to the invention may also com prise tensioning means for keeping the transmission means ten sioned enough. The tensioning means may be based on some sort of weight solution or spring solution. Preferably, the liquid and gas used in the solution are water and gas, respectively, the apparatus being placed in the sea or some other body of water .

The energy production apparatus 3 allows the speed of the downward movement of the movable body 2 to be controlled. For example, as the movable body 2 approaches its bottom dead center, its speed is lowered to stop the movable body at its dead center in a controlled manner, and thereby, to avoid stressing or damaging the structures of the apparatus.

It will be appreciated by a person skilled in the art that the invention is not solely restricted to the above-described ex amples but may vary within the following claims. Hence, some structural solutions may differ from the above. As an example, the movable body may have an open bottom, not requiring the disclosed valve, or the reserve pressure tank can be replaced by periodic use of the compressor.

It will also be appreciated by the person skilled in the art that the movable body may be other than the disclosed cuboid shaped container. Preferably, the movable body can be recti linear in shape in order not to create adverse currents in the liquid . Further, it will be appreciated by the person skilled in the art that the apparatus can be constructed elsewhere than in a body of water. The apparatus can be constructed on the ground or in a mine, for example, provided that the structures and requirements of the invention are met.