DEVICE AND METHOD FOR REVERSIBLE STORAGE AND RELEASE OF ENERGY

Description

[0001] The present invention relates to a device for the reversible storage and release of energy in the form of electrical energy. The device comprises two water reservoirs arranged one above the other, between which two water tanks move alternately upwards when empty and downwards when filled with water, wherein the downward movement of a full water tank drives a generator for electricity production and an empty water tank is pulled upwards. The present invention also relates to a method for generating electrical energy.

[0002] The generation of electricity from alternative energy sources, especially wind power, hydropower, and solar energy, is subject to natural fluctuations. An industrial society can only reliably utilize these alternative energy sources if they are continuously available.

[0003] One way to continuously feed electrical energy from alternative energy sources into the grid is to store the energy for extended periods. This can be achieved, for example, with direct storage systems or pumped-storage hydroelectric plants. However, direct storage systems have the disadvantage of high storage losses and are very expensive. Pumped-storage hydroelectric plants can only be used in limited locations (e.g., artificial reservoirs) and are therefore unsuitable, for example, for the intermediate storage of offshore wind energy.

[0004] WO 2010 / 080074 A1 discloses a device for generating energy using gravity. The device consists of two water tanks that move vertically in opposite directions periodically between two water reservoirs, the downward-moving tank being full and the upward-moving tank being empty. This downward movement sets a wheel in motion and generates a bending moment, which is transmitted to the power generator via a gear at the end of the axle.

[0005] The device's structure is shown schematically below. Both water tanks have a valve at the bottom that opens as soon as a sensor (20) detects that the water tank is in the lower position above the lower water reservoir. The sensor also triggers a brake (40) to absorb strong tensile forces on the water tank. The valve closes as soon as the water tank leaves the lower position. Similarly, the upper water reservoirs are equipped with valves at the bottom for filling the tanks. A sensor (26) on the upper water reservoir ensures that the valve opens only when a water tank is in the upper position. The water tanks are held in the upper position by a lever lock (24). The lever lock is also controlled by the sensor.

[0006] CN 201155434 Y discloses a device for generating kinetic and electrical energy using adjustable gravity, characterized in that it consists of a storage basin, a gravity-driven traction device, and a transmission device. The storage basin is equipped with a water storage tank and has a quantitative groove in its interior. The gravity-driven traction device consists of a steel cable and a pulley system, wherein the steel cable is guided through the pulley system and its two ends are each supported by a weight container (water tank). Furthermore, the pulley system consists of a left and a right transmission pulley.

[0007] The object of the present invention is therefore to provide a device that can (reversibly) store electrical energy from wind power, solar energy or hydropower and continuously release it when needed.

[0008] This problem is solved by the technical teaching of the independent claims of the present invention. Further advantageous embodiments of the invention will become apparent from the dependent claims, the description, and the examples.

[0009] The device (1) according to the invention for reversibly storing and releasing energy uses an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) has a higher potential energy, so that consequently, to store electrical energy, water can be pumped from the lower water reservoir (200) into the upper water reservoir (100) and, to recover the electrical energy, water can be transported from the upper water reservoir (100) into the lower water reservoir (200).

[0010] According to the invention, this transport of water from the upper water reservoir (100) to the lower water reservoir (200) is carried out by means of two water tanks (500, 550) which move alternately upwards and downwards between the water reservoirs.

[0011] While one water tank is being emptied at the lower reservoir, the other water tank at the upper reservoir is being filled. Once full, the tank moves downwards due to gravity. The empty tank at the lower reservoir is pulled upwards until it reaches the upper reservoir and is refilled.

[0012] Both water tanks are connected to a drive unit, which in turn drives the generator as soon as the water tanks move. The movement of the water tanks is coordinated by the drive unit, so that when one water tank is at the upper water reservoir, the other water tank is at the lower water reservoir. If one water tank moves upwards, the other water tank moves downwards. Since the downward-moving water tank is always full of water and the upward-moving water tank is always empty, the former is heavier than the latter, so the empty tank is pulled upwards. Therefore, no electrical energy or motor is required for the transport of the water tank to the upper water reservoir according to the invention.

[0013] The water tanks are filled and emptied via self-closing valves located at the bottom of the water tanks and at the bottom of the upper water reservoir. Self-closing valves are always closed unless a mechanical force is applied to them from below. Therefore, the device according to the invention has corresponding valve opening devices on the top of the water tanks and at the bottom of the lower water reservoir. These devices exert a mechanical force on the self-closing valves when the water tanks are in their uppermost or lowermost position, causing the valves to open and water to flow into or out of the water tank.

[0014] For efficient operation of the device, the water tanks, including the upper and lower reservoirs, must form a vertical axis. This maximizes the use of gravity during downward movement and minimizes any frictional losses. Furthermore, the vertical alignment ensures that the valves and valve opening mechanisms are correctly positioned, allowing the valves to open properly.

[0015] The device according to the invention is therefore not a hydroelectric power plant or a pumped-storage power plant. In a hydroelectric power plant, electrical energy is generated by a volumetric flow rate (volume per unit of time), e.g., a river flowing through a turbine. In contrast, in the present invention, a volumetric flow rate only occurs during the storage process, when the water is transported from the lower reservoir to the upper reservoir by means of a pump and pipeline system. During the release process, i.e., when electrical energy is released, the water is only moved within the tanks. There is no volumetric flow rate. Rather, the mass of the water is used to generate energy (mass effect).

[0016] Thus, the present invention relates to a device (1) for reversibly storing and releasing energy comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402); b) a first water tank (500) having a valve opening device (403) at its top and a self-closing valve (303) at its bottom, wherein the first water tank (500) is arranged such thatthat it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at a top position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a bottom position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500); c) a second identical water tank (550) having a valve opening device (404) on its top and a self-closing valve (304) on its bottom, wherein the second water tank (550) is arranged such thatthat it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at a top position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a bottom position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200); e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) to the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position,until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700), wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposing periodic movement of the water tanks (500, 550), and wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element attached to the top of the first water tank (500). (522) includes,wherein the pivotably mounted locking element (521) is held in a first position by a counterweight (523) in which the protruding element (522) rests on the locking element (521) when the first water tank (500) is in the uppermost position, and wherein the locking element (521) pivots into a second position in which the protruding element (522) does not rest on the locking element (521) when the weight of the first water tank (500) is greater than the counterweight (523); and wherein the second retaining device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550), wherein the pivotally mounted locking element (561) is held in a first position by a counterweight (563) in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in the uppermost position,and wherein the locking element (561) pivots into a second position in which the protruding element (562) does not rest on the locking element (561) when the weight of the second water tank (550) is greater than the counterweight (563).

[0017] To ensure optimal energy recovery, the two water tanks (500, 550) Identical in construction. "Identical in construction" here means that the water tanks are identical or at least nearly identical in their dimensions and weight (identical except for manufacturing tolerances). The identical water tanks (500, 550) therefore have essentially the same volume and weight. They may, but do not necessarily have to, be made of the same material.

[0018] The two water tanks (500, 550) of the device (1) according to the invention for reversibly storing and releasing energy move periodicallyand in the opposite direction. Here, "periodic motion" means a motion in which the water tank, after a certain time, the period, It returns to its starting point, maintaining the same direction and speed. The vertical axis formed by the upper and lower water tanks is repeatedly traversed by the water tanks; that is, the periodic motion of the water tanks describes a closed trajectory.

[0019] The efficiency of energy release depends on the period. A longer period leads to more efficient energy release. Therefore, it is advantageous to operate the device with the longest possible period, i.e., with the slowest possible movement of the water tanks.

[0020] In a preferred embodiment, the self-closing valves consist of a valve seat (310), a valve disc (320), a valve spindle (330), a valve spindle dome (340) and a coil spring (350) (see Figure 2 The coil spring is located between the valve stem dome and the valve disc and keeps the valve closed. If an external mechanical force acts against the spring-loaded valve disc, it is pushed upwards and the valve opens as soon as the mechanical force is greater than the spring force.

[0021] Thus, the present invention relates to a device (1) for reversibly storing and releasing energy comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402); b) a first water tank (500) having a valve opening device (403) at its top and a self-closing valve (303) at its bottom, wherein the first water tank (500) is arranged such thatthat it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at a top position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a bottom position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500); c) a second identical water tank (550) having a valve opening device (404) on its top and a self-closing valve (304) on its bottom, wherein the second water tank (550) is arranged such thatthat it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at a top position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a bottom position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200); e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) to the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position,until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity that is connected to the drive unit (700), wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element (522) attached to the top of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the projecting element (522) rests on the locking element (521) when the first water tank (500) is in the uppermost position,and wherein the locking element (521) pivots into a second position in which the protruding element (522) does not rest on the locking element (521) when the weight of the first water tank (500) is greater than the counterweight (523); and wherein the second retaining device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550), wherein the pivotally mounted locking element (561) is held by a counterweight (563) in a first position in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in the uppermost position, and wherein the locking element (561) pivots into a second position in which the projecting element (562) does not rest on the locking element (561) when the weight of the second water tank (550) is greater than the counterweight (563), wherein the first and second water tanks (500,550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposing periodic movement of the water tanks (500, 550), and wherein the self-closing valves (301-304) comprise a valve seat (310), a valve disc (320), a valve spindle (330) and a valve spindle dome (340), and wherein the valves (301-304) are held closed by a spring (350) located between the valve spindle dome (340) and the valve disc (320).

[0022] In a preferred embodiment, the valve opening devices of the device according to the invention have height-adjustable pins. These pins are shaped such that they can open the self-closing valves by pushing the valve back. Therefore, the pins are also mechanically stable enough to withstand the spring force of the coil spring (350). The height of the pins allows the opening of the self-closing valves to be adjusted, and thus also the volume flow, the starting mass, and the filling time.

[0023] The efficiency of energy release depends not only on the period but also on the mass of the filled water tanks (500, 550) ("departure mass"). A higher departure mass leads to more efficient energy release. Therefore, it is advantageous to fill the water tanks in the uppermost position as completely as possible.

[0024] Thus, the present invention relates to a device (1) for reversibly storing and releasing energy comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at an uppermost position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a lowermost position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element (522) attached to the top of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the projecting element (522) rests on the locking element (521) when the first water tank (500) is in its uppermost position, and wherein the locking element (521) pivots into a second position in which the projecting element (522) does not rest on the locking element (521) when the weight of the first water tank (500) is greater than the counterweight (523); and wherein the second holding device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550),wherein the pivotally mounted locking element (561) is held in a first position by a counterweight (563) in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in the uppermost position, and wherein the locking element (561) pivots into a second position in which the projecting element (562) does not rest on the locking element (561) when the weight of the second water tank (550) is greater than the counterweight (563), wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity by the opposing periodic movement of the water tanks (500, 550), and wherein the valve opening devices (401-404) have height-adjustable pins (411-414) shaped such that they Open the self-closing valves (301-304).

[0025] A preferred embodiment of the device (1) according to the invention comprises the following components: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at an uppermost position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a lowermost position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposing periodic movement of the water tanks (500, 550), wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element (522) attached to the top of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the projecting element (522) rests on the locking element (521) when the first water tank (500) is in the uppermost position, and wherein the locking element (521) pivots into a second position in which the projecting element (522) does not rest on the locking element (521),if the weight of the first water tank (500) is greater than the counterweight (523); and wherein the second retaining device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550), wherein the pivotally mounted locking element (561) is held by a counterweight (563) in a first position in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in the uppermost position, and wherein the locking element (561) pivots into a second position in which the projecting element (562) does not rest on the locking element (561) when the weight of the second water tank (550) is greater than the counterweight (563), wherein the self-closing valves (301-304) comprise a valve seat (310), a valve disc (320),comprising a valve spindle (330) and a valve spindle dome (340), wherein the valves (301-304) are held closed by a spring (350) located between the valve spindle dome (340) and the valve disc (320), and wherein the valve opening devices (401-404) have height-adjustable pins (411-414) shaped to open the self-closing valves (301-304).

[0026] In a further embodiment of the present invention, the device also includes a mass flywheel (750) for absorbing the force generated during the downward movement of a water tank (500, 550). The mass flywheel fulfills three functions in the device according to the invention: First, it absorbs the briefly high force of the downward-moving water tanks, and second, it transmits this force to the power generator (800) with a time delay. This keeps the system in motion, even during the phases in which both water tanks are being filled and emptied. Furthermore, the resistance of the mass flywheel has a positive effect on the downward movement of the water tank, because a slower downward movement allows the mass flywheel to absorb more energy. Thus, the present invention relates to a device (1) for the reversible storage and release of energy comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis such that, at its uppermost position, its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at its lowest position, the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposing periodic movement of the water tanks (500, 550), wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element (522) attached to the top of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the projecting element (522) rests on the locking element (521) when the first water tank (500) is in its uppermost position, and wherein the locking element (521) pivots into a second position in which the projecting element (522) does not rest on the locking element (521) when the weight of the first water tank (500) is greater than the counterweight (523);and wherein the second holding device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550), wherein the pivotally mounted locking element (561) is held by a counterweight (563) in a first position in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in its uppermost position, and wherein the locking element (561) pivots into a second position in which the projecting element (562) does not rest on the locking element (564) when the weight of the second water tank (550) is greater than the counterweight (563), and wherein the drive unit (700) further comprises a mass flywheel (750) for absorbing the force generated during the downward movement of a water tank (500, 550).

[0027] Since the water tank being filled would already start to move downwards as soon as it is heavier than the emptying water tank, it is necessary to fix (hold) the water tank being filled in the uppermost position until it has reached the desired fill level or is preferably completely full.

[0028] For this purpose, the device according to the invention is equipped with holding devices (520, 560).

[0029] Suitable holding devices (520, 560) are all types of holding devices capable of keeping the water tank in the uppermost position during filling only until the water tank is filled with a defined quantity of water or completely filled with water. The water tanks can be fixed in the uppermost position by the holding devices using various mechanisms.

[0030] According to the invention, the holding devices are designed to comprise a pivotably mounted locking element and a protruding element attached to the top of the water tank. The pivotably mounted locking element is held in a first position by a counterweight, in which the protruding element rests on the locking element when the water tank is in its uppermost position. Thus, the locking element is weight-loaded on two axes and pivots downwards (preferably by 90°). The counterweight corresponds to the mass of a filled water tank.

[0031] As the water tank moves upwards towards the upper water reservoir, the protruding element, which may be a convex surface (see Figure 3) and is attached to the top of the water tank, the locking element is briefly inserted. The water tank rests with the straight side of the protruding element on the locking element and is thereby held below the upper water reservoir until the weight of the fully filled water tank is sufficient to fold down the locking element, which is loaded with the counterweight (preferably by 90°), thus allowing the downward movement of the water tank. The present invention therefore relates to a device (1) for the reversible storage and release of energy comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at an uppermost position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a lowermost position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposing periodic movement of the water tanks (500, 550), and wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element (522) attached to the top of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the projecting element (522) rests on the locking element (521) when the first water tank (500) is in its uppermost position, and wherein the locking element (521) pivots into a second position in which the projecting element (522) does not rest on the locking element (521) when the weight of the first water tank (500) is greater as the counterweight (523);and wherein the second retaining device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550), wherein the pivotally mounted locking element (561) is held by a counterweight (563) in a first position in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in its uppermost position, and wherein the locking element (561) pivots into a second position in which the projecting element (562) does not rest on the locking element (561) when the weight of the second water tank (550) is greater than the counterweight (563).

[0032] A holding device designed in this way allows for easy adjustment of the counterweight force, which holds the water tank in the uppermost position until a defined fill level is reached. Therefore, in principle, no further means of detecting the fill level, such as an optical sensor, is required.

[0033] Alternatively, the water tanks can be held in the uppermost position electromagnetically. The holding force with which the device secures the water tank can be precisely adjusted via the voltage applied to the electromagnet. If the weight of the filled water tank exceeds the force of the electromagnet, the tank moves back down. Therefore, in principle, no further means of detecting the fill level are necessary. However, the holding device can also be designed so that the voltage applied to the electromagnet is switched off when a defined fill level is reached. In this case, the fill level can be determined using another method, such as an optical sensor, a weight sensor, or a float in the water tank.

[0034] A device (1) for reversibly storing and releasing energy as described herein comprises: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at an uppermost position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a lowermost position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) equipped with an electromagnet, which holds the first water tank (500) in the uppermost position by means of the electromagnet until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) equipped with an electromagnet, which holds the second water tank (550) in the uppermost position by means of the electromagnet until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) which is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposite periodic movement of the water tanks (500, 550).

[0035] The electromagnet of the holding device is arranged such that it comes into contact with the water tank when the latter reaches its uppermost position. To exert a holding force on the water tank, the water tank is made of a magnetic material, preferably a ferromagnetic material, e.g., certain types of steel, or the water tank is provided with an armature plate made of a magnetic material. The electromagnet exerts a holding force on this armature plate as soon as the water tank reaches its uppermost position. Thus, a device (1) for the reversible storage and release of energy is described herein, comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at an uppermost position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a lowermost position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) equipped with an electromagnet, which holds the first water tank (500) in the uppermost position by means of the electromagnet until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) equipped with an electromagnet, which holds the second water tank (550) in the uppermost position by means of the electromagnet until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) which is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates current by the opposite periodic movement of the water tanks (500, 550), and wherein the holding devices (520, 560) each comprise an anchor plate attached to the water tanks (500, 550), and the anchor plates are in contact with the electromagnets when the water tanks (500, 550) are in the uppermost position.

[0036] For energy generation, it is particularly advantageous if the lower water tank is completely empty before the upper water tank is completely filled and begins its downward movement. To ensure that the lower water tank empties faster than the upper water tank fills, the valves at the bottom of the water tanks can be opened wider than the valves at the bottom of the upper water tank by means of the appropriate valve opening devices.

[0037] In a preferred embodiment, the valve opening devices on the bottom of the lower water reservoir can have a higher pin than the pins of the valve opening devices on the top of the first water tank and the second water tank.

[0038] Thus, the present invention also relates to a device (1) comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at an uppermost position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a lowermost position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposing periodic movement of the water tanks (500, 550), wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element (522) attached to the top of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the projecting element (522) rests on the locking element (521) when the first water tank (500) is in the uppermost position, and wherein the locking element (521) pivots into a second position in which the projecting element (522) does not rest on the locking element (521),if the weight of the first water tank (500) is greater than the counterweight (523); and wherein the second retaining device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550), wherein the pivotally mounted locking element (561) is held by a counterweight (563) in a first position in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in the uppermost position, and wherein the locking element (561) pivots into a second position in which the projecting element (562) does not rest on the locking element (561) when the weight of the second water tank (550) is greater than the counterweight (563), wherein the self-closing valves (301-304) comprise a valve seat (310), a valve disc (320),comprising a valve spindle (330) and a valve spindle dome (340), wherein the valves (301-304) are held closed by a spring (350) located between the valve spindle dome (340) and the valve disc (320), wherein the valve opening devices (401-404) have height-adjustable pins (411-414) shaped to open the self-closing valves (301-304), and wherein the valve opening devices (401, 402) on the bottom of the lower water reservoir (200) have a higher pin (411, 412) than the pins (413, 414) of the valve opening devices (403, 404) on the top of the first water tank (500) and the second water tank (550) to ensure that a water tank can be filled into the lower water reservoir (200) is emptied faster than a water tank at the upper water reservoir (100) is filled.

[0039] For increased stability of the device and the directed upward and downward movement of the water tanks, these can be mounted on vertical guide rails (680). Thus, in a further embodiment of the invention, the upward and downward movement of the first water tank (500) and the second water tank (550) takes place in guide rails (680).

[0040] Furthermore, it is advantageous if the water tanks are equipped with transparent level gauge tubes on the sides, so that level adjustments are possible during operation and the level in the water tanks is visible.

[0041] The drive unit (700) of the device according to the invention ensures that the water tanks move upwards and that a generator (800) is driven during the downward movement of a water tank. In a preferred embodiment, the energy generated by the alternating upward and downward movement of the water tanks is transmitted to the generator (800) via a chain (784) attached to the water tanks. Preferably, the chain is stretched vertically over the entire travel distance of the water tanks via two gears (701, 702), with one gear (701) located centrally between the two tanks of the lower water reservoir and the second gear (702) located above the upper water reservoir on a shaft (704) connected to the generator. As soon as a water tank moves, the shaft (704) rotates to the right or to the left, depending on which water tank is moving downwards.

[0042] Thus, the present invention also relates to a device (1) comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at an uppermost position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a lowermost position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposing periodic movement of the water tanks (500, 550), wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element (522) attached to the top of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the projecting element (522) rests on the locking element (521) when the first water tank (500) is in the uppermost position, and wherein the locking element (521) pivots into a second position in which the projecting element (522) does not rest on the locking element (521),if the weight of the first water tank (500) is greater than the counterweight (523); and wherein the second holding device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550), wherein the pivotally mounted locking element (561) is held by a counterweight (563) in a first position in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in the uppermost position, and wherein the locking element (561) pivots into a second position in which the projecting element (562) does not rest on the locking element (561) when the weight of the second water tank (550) is greater than the counterweight (563), and wherein the drive unit (700) comprises the following components: a gear (701) arranged centrally between the containers of the lower water reservoir (200),a gear (702) arranged centrally between the containers of the upper water reservoir (100), a chain (703) stretched between the two gears (701, 702) which is connected to the first water tank (500) and the second water tank (550), and a shaft (704) via which the gear (702) arranged centrally between the containers of the upper water reservoir (100) drives the generator (800).

[0043] To prevent uneven loading or even tilting of the water tanks by the drive unit (700), the water tanks of the device according to the invention can be connected to a further drive unit (710). The further drive unit is then connected to the water tanks on the opposite side of the first drive unit (700) to enable uniform movement of the water tanks.

[0044] This drive unit (710) can consist of the same components as the drive unit (700), i.e., to the side of the water tanks, opposite the drive chain, another chain is connected to the water tank in a chain tensioning device. This chain runs over the upper water reservoir and is connected to the second water tank in the same manner. Thus, a second force now acts in equilibrium on the opposite side of the water tank, where the drive unit (700) is connected. Since the same forces now act at all connections, the water tank is pulled straight by the counterweight of the second water tank.

[0045] Thus, the present invention also relates to a device (1) comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at an uppermost position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a lowermost position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposing periodic movement of the water tanks (500, 550), wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element (522) attached to the top of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the projecting element (522) rests on the locking element (521) when the first water tank (500) is in the uppermost position, and wherein the locking element (521) pivots into a second position in which the projecting element (522) does not rest on the locking element (521),if the weight of the first water tank (500) is greater than the counterweight (523); and wherein the second holding device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550), wherein the pivotally mounted locking element (561) is held by a counterweight (563) in a first position in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in the uppermost position, and wherein the locking element (561) pivots into a second position in which the projecting element (562) does not rest on the locking element (561) when the weight of the second water tank (550) is greater than the counterweight (563), and wherein the device (1) further comprises a further drive unit (710) which is connected to the first water tank (500) and the second water tank (550) opposite the drive unit (700),to ensure that the upward and downward movement of the first water tank (500) and the second water tank (550) by the drive unit (700) is uniform.

[0046] Due to the periodically alternating upward and downward movement of the water tanks and the resulting lateral reversal of the power input, different directions of rotation occur on the shaft (704). This means that the shaft sometimes applies the power in the counterclockwise direction of rotation and at other times in the clockwise direction of rotation.

[0047] In order to convert the periodically alternating downward and upward movement of the water tanks into a synchronous rotary movement, the device can also be equipped with a conversion gear.

[0048] Thus, the present invention also relates to a device (1) comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at an uppermost position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a lowermost position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposing periodic movement of the water tanks (500, 550), wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element (522) attached to the top of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the projecting element (522) rests on the locking element (521) when the first water tank (500) is in its uppermost position, and wherein the locking element (521) pivots into a second position in which the projecting element (522) does not rest on the locking element (521) when the weight of the first water tank (500) is greater than the counterweight (523);and wherein the second holding device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550), wherein the pivotally mounted locking element (561) is held by a counterweight (563) in a first position in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in its uppermost position, and wherein the locking element (561) pivots into a second position in which the projecting element (562) does not rest on the locking element (564) when the weight of the second water tank (550) is greater than the counterweight (563), and wherein the drive unit (700) further comprises a conversion gear (780) for converting the periodically alternating downward and upward movement of the water tanks into a synchronous rotary movement, and the generator (800) is connected to the conversion gear (780).

[0049] In a preferred embodiment, the transmission (780) comprises a generator shaft (781) on which two freewheel gears (782a, 782b) are arranged, wherein the freewheel gear (782a) is connected via a chain (784a) to a freewheel gear (785a) arranged on the shaft (704), the freewheel gear (782b) is connected via a chain (784b) to a freewheel gear (785b) arranged on a second shaft (704b), wherein a gear (783a) arranged on the shaft (704) engages with a gear (783b) arranged on the second shaft (704b), and wherein the generator (800) is driven via the generator shaft (781) (See Figure 4 The two shafts (704) and (704b) are arranged such that the gears (783a, 783b) mesh and the rotation of shaft (704) causes the second shaft (704b) to rotate in the opposite direction. The shafts can usually be held in ball bearing shaft supports (788).

[0050] In this embodiment of the drive unit (700), the alternating downward movement of the water tanks exerts a force on the shaft (704) (e.g., via a coupling), first in the counterclockwise direction and then in the clockwise direction. The freewheel gears (785a, 785b) arranged on the shaft (704) and the second shaft (704b) are configured identically, so that only one of the freewheel gears rotates when the shaft is moved. For example, if the shaft (704) rotates clockwise, the freewheel gear (785a) also rotates clockwise due to friction on the shaft. The force is transmitted via the chain (784a) to the freewheel gear (782a), thus driving the freely rotating generator shaft (781) also clockwise. The rotary motion of the generator shaft (781) then drives the generator (800) and can also be used to set a mass flywheel (750) into rotation.If, on the other hand, shaft (704) rotates counterclockwise (to the left), the freewheel gear (785a) runs freely. The gear (783a) connected to shaft (704) also rotates counterclockwise, causing the gear (783b) connected to the second shaft (704b) to rotate clockwise. The second shaft thus rotates clockwise, causing the freewheel gear (785b) to also rotate clockwise due to friction on the shaft. The force is transmitted via the chain (784b) to the freewheel gear (782b), thereby also driving the freely rotating generator shaft (781) clockwise. Finally, the generator shaft (781) is driven only clockwise, regardless of the direction in which shaft (704) is rotated.

[0051] The above descriptions are only an example of driving a generator shaft clockwise. The freewheel of the gears (785a, 785b, 782a, 782b) can also be set in the opposite direction, so that the generator shaft is driven counterclockwise.

[0052] Thus, the present invention also relates to a device (1) comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at an uppermost position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a lowermost position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposing periodic movement of the water tanks (500, 550), wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element (522) attached to the top of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the projecting element (522) rests on the locking element (521) when the first water tank (500) is in the uppermost position, and wherein the locking element (521) pivots into a second position in which the projecting element (522) does not rest on the locking element (521),when the weight of the first water tank (500) is greater than the counterweight (523); and wherein the second holding device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550), wherein the pivotally mounted locking element (561) is held by a counterweight (563) in a first position in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in the uppermost position, and wherein the locking element (561) pivots into a second position in which the projecting element (562) does not rest on the locking element (561) when the weight of the second water tank (550) is greater than the counterweight (563),wherein the drive unit (700) further comprises a transmission (780) for converting the periodically alternating downward and upward movement of the water tanks into a synchronous rotary movement and the generator (800) is connected to the transmission (780), and wherein the transmission (780) comprises a generator shaft (781) on which two freewheel gears (782a, 782b) are arranged, wherein the freewheel gear (782a) is connected via a chain (784a) to a freewheel gear (785a) arranged on the shaft (704), the freewheel gear (782b) is connected via a chain (784b) to a freewheel gear (785b) arranged on a second shaft (704b), wherein a gear (783a) arranged on the shaft (704) engages with a gear (783b) arranged on the second shaft (704b), and wherein the generator (800) is driven via the generator shaft (781).

[0053] In a further preferred embodiment, the conversion gear (780) comprises a generator shaft (781) on which a freewheel gear (782) and a gear (783a) are arranged, wherein the freewheel gear (782) is connected via a chain (784) to a gear (783b) arranged on the shaft (704), the gear (783a) engages in a freewheel gear (785) arranged on the shaft (704), and wherein the generator (800) is driven via the generator shaft (781).

[0054] Thus, the present invention also relates to a device (1) comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at an uppermost position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a lowermost position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposing periodic movement of the water tanks (500, 550), wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element (522) attached to the top of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the projecting element (522) rests on the locking element (521) when the first water tank (500) is in the uppermost position, and wherein the locking element (521) pivots into a second position in which the projecting element (522) does not rest on the locking element (521),when the weight of the first water tank (500) is greater than the counterweight (523); and wherein the second holding device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550), wherein the pivotally mounted locking element (561) is held by a counterweight (563) in a first position in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in the uppermost position, and wherein the locking element (561) pivots into a second position in which the projecting element (562) does not rest on the locking element (561) when the weight of the second water tank (550) is greater than the counterweight (563),wherein the drive unit (700) further comprises a transmission (780) for converting the periodically alternating downward and upward movement of the water tanks into a synchronous rotary movement, and wherein the generator (800) is connected to the transmission (780), and wherein the transmission (780) comprises a generator shaft (781) on which a freewheel gear (782) and a gear (783a) are arranged, wherein the freewheel gear (782) is connected via a chain (784) to a gear (783b) arranged on the shaft (704), the gear (783a) engages with a freewheel gear (785) arranged on the shaft (704), and wherein the generator (800) is driven via the generator shaft (781).

[0055] Preferably, the generator shaft (781) of the conversion gear (780) in the devices (1) described herein according to the invention further comprises a mass flywheel (750) for receiving the force generated during the downward movement of a water tank (500, 550).

[0056] In a further embodiment, the upper water reservoir (100) of the device according to the invention described herein can also include a further container (130) for receiving rainwater.

[0057] In a further embodiment, the device according to the invention can have a check valve (660) and a maintenance device (670) with a flushing valve (671) connected to the line (600) behind the pump (650) for pumping water from the lower water reservoir (200) into the upper water reservoir (100) in the pumping direction.

[0058] Another aspect of the present invention relates to a method for generating electricity, comprising the steps of: a) Providing a device (1) described herein for reversibly storing and releasing energy, wherein one water tank (500) is in the uppermost position and the other water tank (550) is in the lowermost position; b) Filling the water tank (500) in the uppermost position with water from the upper water reservoir (100) by opening the self-closing valve (301) by means of the valve opening device (403); c) The water tank (500) at the uppermost position can be moved downwards to the lowest position by means of gravity by releasing the holding device (520) and thereby, by means of the drive unit (700), the water tank (550) at the lowest position can be pulled upwards to the uppermost position and the generator (800) can be driven to generate electricity, d) Emptying the water tank (500) at the lowest position into the lower water reservoir (200) by opening the self-closing valve (303) by means of the valve opening device (401).

[0059] Energy storage systems serve to decouple energy generation and demand over time. This allows them to compensate for fluctuating energy supply, improve security of supply, and stabilize the electricity grid. These facilities are built where they generate the most energy – for wind power, this is onshore, in regions with high wind loads, and offshore. While electricity feed-in from photovoltaics is already subject to day-night fluctuations, wind power, in particular, delivers electricity in a highly unpredictable and uneven manner. During strong winds, wind turbines must be temporarily disconnected from the grid in areas where grid overload would otherwise occur. Pumped-storage hydroelectric plants are currently the most efficient energy storage solutions, but due to their design, they are located in mountainous regions. The energy transfer from decentralized, renewable energy power plants to these locations inevitably results in grid losses.Furthermore, the grid is insufficiently developed in some regions. Therefore, decentralized energy storage near the power generation site would be advantageous, i.e., near or within the wind turbine.

[0060] Thus, another aspect of the present invention relates to a wind power plant (900) comprising a device (1) for reversibly storing and releasing energy comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), both containers communicating with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottom with a valve opening device (401, 402);b) a first water tank (500) having a valve opening device (403) on its upper side and a self-closing valve (303) on its lower side, wherein the first water tank (500) is arranged such that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and with the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on this vertical axis, such that at an uppermost position its valve opening device (403) opens the self-closing valve (301) of the first container (110), and at a lowermost position the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500);c) a second identical water tank (550) having a valve opening device (404) on its upper side and a self-closing valve (304) on its lower side, wherein the second water tank (550) is arranged such that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and with the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is movable on this vertical axis opposite to the first water tank (500) and periodically, so that at an uppermost position its valve opening device (404) opens the self-closing valve (302) of the second container (120), and at a lowermost position the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200);e) a pump (650) connected to the pipe for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520) that holds the first water tank (500) in the uppermost position until the first water tank (500) is filled with a defined quantity of water, and a second holding device (560) that holds the second water tank (550) in the uppermost position until the second water tank (550) is filled with a defined quantity of water, g) a drive unit (700) that is connected to and arranged between the first water tank (500) and the second water tank (550), and h) a generator (800) for generating electricity, which is connected to the drive unit (700); wherein the first and second water tanks (500, 550) are in drive contact with the generator (800) via the drive unit (700), which generates electricity through the opposing periodic movement of the water tanks (500, 550), wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a projecting element (522) attached to the top of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the projecting element (522) rests on the locking element (521) when the first water tank (500) is in the uppermost position, and wherein the locking element (521) pivots into a second position in which the projecting element (522) does not rest on the locking element (521),when the weight of the first water tank (500) is greater than the counterweight (523); and wherein the second holding device (560) comprises a pivotally mounted locking element (561) and a projecting element (562) attached to the top of the second water tank (550), wherein the pivotally mounted locking element (561) is held by a counterweight (563) in a first position in which the projecting element (562) rests on the locking element (564) when the second water tank (550) is in the uppermost position, and wherein the locking element (561) pivots into a second position in which the projecting element (562) does not rest on the locking element (561),if the weight of the second water tank (550) is greater than the counterweight (563). Due to the modular and compact design of the device (1) according to the invention, it can be operated inside the tower (910) of a wind turbine (900). The electricity from the wind power drives the pump (650), which pumps the water from the lower reservoir (200) to the upper reservoir (100), thus storing the energy. During periods of low wind, the energy stored in this way can then be fed into the grid for a constant power supply. In strong winds, when the wind turbine would have to be taken offline, the excess wind energy can be directed into the device (1) to avoid grid overload. The wind turbine would then not have to be taken offline but could continue to feed electricity into the grid.

[0061] Thus, in one embodiment, the wind turbine (900) comprises a device (1) disclosed herein for reversibly storing and releasing energy, wherein the device (1) is positioned in the tower (910) of the wind turbine (910).

[0062] The outer surfaces of the tower (910) can additionally be lined with solar panels (920) for electricity generation. The electricity from the solar panels (920) can be used to operate the pump (650). Therefore, the present invention also relates to a wind turbine (900) comprising a device (1) disclosed herein for reversibly storing and releasing energy, wherein the device (1) is positioned in the tower (910) of the wind turbine (910) and the outer surface of the tower (910) is lined with solar panels (920) for electricity generation. Character description

[0063] Figure 1 shows a device (1) according to the invention for reversibly storing and releasing energy. Figure 2Figure 3 shows a preferred embodiment of the self-closing valve (300) comprising a valve seat (310), a valve disc (320), a valve spindle (330), a valve spindle dome (340) and a coil spring (350) which keeps the valve closed. Figure 3 Figure 1 shows a preferred embodiment of the holding device (520, 560) with a locking element (521, 561) which is pivotably mounted on the two axes (524, 564) and is held in a holding position by means of a counterweight (523, 563) until a force acts on the locking element which is greater than the weight of the counterweight and pivots the locking element into a second position in which the water tank (500, 550) is no longer held. Figure 4Figure 1 schematically shows a preferred embodiment of the drive unit (700) with a transmission (780) and a flywheel (750). In this example, the transmission (780) consists of a generator shaft (781) with two freewheel gears (782a, 782b), a shaft (704) with a freewheel gear (785a) and a gear (783a), and a second shaft (704b) with a freewheel gear (785b) and a gear (783b). The freewheel gears (782a, 782b, 785a, 785) are connected to each other via a chain (784a, 784b). The two shafts (704) and (704b) are arranged such that the gears (783a,783b) mesh together and the rotation of shaft (704) causes the second shaft (704b) to rotate in the opposite direction. Reference symbol list

[0064] 1 Device for reversible energy storage and release 100 Upper water reservoir 110 First tank 120 Second tank 130 Rainwater tank 200 Lower water reservoir 210 First tank 220 Second tank 300-304 Self-closing valve 310 Valve seat 320 Valve disc 330 Valve spindle 340 Valve spindle dome 350 Spring 401-404 Valve opening device 411-414 Height-adjustable pins 500 First water tank 520 First holding device 521 Swivel-mounted locking element 522 Protruding element 523 Counterweight 524 Axle 550 Second water tank 560 Second holding device 561 Swivel-mounted locking element 562 Protruding element 563 Counterweight 564 Axle 600 Line 650 Pump 660 Check valve 670 Maintenance device 671 Flushing valve 680 Guide rails 700 Drive unit 701, 702 Gear 703 Chain 704, 704b Shaft 750 Mass flywheel 780 Converter gearbox 781 Generator shaft 782, 782a, 782b Freewheel gear 783, 783a, 783b Gear 784, 784a, 784b Chain 785, 785a785b Freewheel gear 788 Ball bearing shaft support 800 Generator 900 Wind turbine 910 Tower 920 Solar panel

Claims

1. A device (1) for reversibly storing and releasing of energy, comprising: a) an upper water reservoir (100) and a lower water reservoir (200), wherein the upper water reservoir (100) consists of a first container (110) and a second container (120), wherein both containers communicate with each other and both containers being equipped at their bottom with a self-closing valve (301, 302); wherein the lower water reservoir (200) consists of a first container (210) and a second container (220), both containers communicating with each other and both containers being equipped at their bottoms with a valve opening device (401, 402); b) a first water tank (500), whose upper side has a valve opening device (403) and whose lower side has a self-closing valve (303), wherein the first water tank (500) is arranged so that it forms a vertical axis with the first container (110) of the upper water reservoir (100) and the first container (210) of the lower water reservoir (200), and wherein the first water tank (500) is periodically movable on said vertical axis so that, at an uppermost position, it opens the self-closing valve (301) of the first container (110) and, at a lowest position, the valve opening device (401) of the first container (210) opens the self-closing valve (303) of the first water tank (500); c) a second water tank (550) of similar construction, whose upper side has a valve opening device (404) and whose lower side has a self-closing valve (304), wherein the second water tank (550) is arranged so that it forms a vertical axis with the second container (120) of the upper water reservoir (100) and the second container (220) of the lower water reservoir (200), and wherein the second water tank (550) is oppositely movable to the first water tank (500) on said vertical axis and periodically movable so that, at an uppermost position, it opens the self-closing valve (302) of the second container (120) with its valve opening device (404) and, at a lowest position, the valve opening device (402) of the second container (220) opens the self-closing valve (304) of the second water tank (550); d) a conduit (600) connecting the upper water reservoir (100) and the lower water reservoir (200); e) a pump (650) connected to the conduit for pumping water from the lower water reservoir (200) into the upper water reservoir (100), f) a first holding device (520), which holds the first water tank (500) at the uppermost position until the first water tank (500) is filled with a defined amount of water, and a second holding device (560), which holds the second water tank (550) at the uppermost position until the second water tank (550) is filled with a defined amount of water, g) a drive unit (700) connected to the first water tank (500) and to the second water tank (550) and arranged between them, and h) a generator (800) for generating electrical power, which is connected to the drive unit (700), wherein the first and second water tanks (500, 550) are in driving contact via the drive unit (700) with the generator (800), which generates electrical power by the opposing periodic movement of the water tanks (500, 550), and wherein the first holding device (520) comprises a pivotally mounted locking element (521) and a protruding element (522) attached to the upper side of the first water tank (500), wherein the pivotally mounted locking element (521) is held by a counterweight (523) in a first position in which the protruding element (522) rests on the locking element (521) when the first water tank (500) is in the uppermost position, and wherein the locking element (521) pivots to a second position in which the protruding element (522) does not rest on the locking element (521) when the weight of the first water tank (500) is greater than the counterweight (523); and wherein the second holding device (560) comprises a pivotally mounted locking element (561) and a protruding element (562) attached to the upper side of the second water tank (550), wherein the pivotally mounted locking element (561) is held in a first position by a counterweight (563), in which the protruding element (562) rests on the locking element (564) when the second water tank (550) is in the uppermost position, and wherein the locking element (561) pivots into a second position, in which the protruding element (562) does not rest on the locking element (561) when the weight of the second water tank (550) is greater than the counterweight (563).

2. The device (1) according to claim 1, wherein the self-closing valves (301-304) comprise a valve seat (310), a valve disc (320), a valve spindle (330), and a valve spindle dome (340), and wherein the valves (301-304) are held closed by a spring (350) located between the valve spindle dome (340) and the valve disc (320).

3. The device (1) according to claim 1 or 2, wherein the valve opening devices (401-404) comprise height-adjustable pins (411-414) shaped to open the self-closing valves (301-304).

4. The device (1) according to any one of claims 1 to 3, wherein the drive unit (700) further comprises a mass flywheel (750) for absorbing the force generated during the downward movement of a water tank (500, 550).

5. The device (1) according to claim 3 or 4, wherein the valve opening devices (401, 402) on the bottom of the lower water reservoir (200) have a higher pin (411, 412) than the pins (413, 414) of the valve opening devices (403, 404) on the upper side of the first water tank (500) and the second water tank (550) to ensure that a water tank is emptied into the lower water reservoir (200) faster than a water tank is filled at the upper water reservoir (100).

6. The device (1) according to any one of claims 1 to 5, wherein the upward and downward movement of the first water tank (500) and the second water tank (550) takes place in guide rails (680).

7. The device (1) according to any one of claims 1 to 6, further comprising a further drive unit (710), connected to the first water tank (500) and the second water tank (550) opposite the drive unit (700) to ensure that the upward and downward movement of the first water tank (500) and the second water tank (550) by the drive unit (700) is uniform.

8. The device (1) according to any one of claims 1 to 7, wherein the drive unit (700) comprises the following components: a gear wheel (701) arranged centrally between the containers of the lower water reservoir (200), a gear wheel (702) arranged centrally between the containers of the upper water reservoir (100), a chain (703) stretched between the two gear wheels (701, 702), which is connected to the first water tank (500) and the second water tank (550), and a shaft (704), via which the gear wheel (702) arranged centrally between the containers of the upper water reservoir (100) drives the generator (800).

9. The device (1) according to any one of claims 1 to 8, wherein the drive unit (700) further comprises a conversion gear (780) for converting the periodically alternating downward movement and upward movement of the water tanks into a synchronous rotational movement, and the generator (800) is connected to the conversion gear (780).

10. The device (1) according to claim 9, wherein the conversion gear (780) comprises a generator shaft (781) on which two freewheel gears (782a, 782b) are arranged, wherein the freewheel gear (782a) is connected via a chain (784a) to a freewheel gear (785a) arranged on the shaft (704), the freewheel gear (782b) is connected via a chain (784b) to a freewheel gear (785b) arranged on a second shaft (704b), wherein a gear (783a) arranged on the shaft (704) engages with a gear (783b) arranged on the second shaft (704b), and wherein the generator (800) is driven via the generator shaft (781).

11. The device (1) according to claim 9, wherein the conversion gear (780) comprises a generator shaft (781) on which a freewheel gear (782) and a gear (783a) are arranged, wherein the freewheel gear (782) is connected via a chain (784) to a gear (783b) arranged on the shaft (704), the gear (783a) meshes with a freewheel gear (785) arranged on the shaft (704), and the generator (800) is driven via the generator shaft (781).

12. A wind turbine (900) comprising a device (1) according to any one of claims 1 to 11.

13. A method for generating electrical power, comprising the steps: a) providing a device (1) according to any one of claims 1 to 11, wherein one water tank (500) is at the uppermost position and the other water tank (550) is at the lowermost position; b) filling the water tank (500) at the uppermost position with water from the upper water reservoir (100) by opening the self-closing valve (301) by means of the valve opening device (403); c) allowing the water tank (500) at the uppermost position to move downward to the lowest position by means of gravity by releasing the holding device (520) and thereby pulling the water tank (550) at the lowest position upward to the uppermost position by means of the drive unit (700) and driving the generator (800) for electric power generation, d) emptying the water tank (500) at the lowest position into the lower water reservoir (200) by opening the self-closing valve (303) by means of the valve opening device (401).