UNDERWATER ENERGY STORAGE SYSTEM AND POWER STATION POWERED THEREWITH

1 . An underwater energy storage system comprising:

a tank for storing a compressed gas that is adapted to be stored underwater, the tank enclosing a constant volume and comprising:

at least one water opening through which water from surrounding environment can flow into and out of the tank; and

floating structures adapted to cover a surface of the water contained in the tank;

at least one gas opening through which the compressed gas is received; and

at least one duct communicating between the at least one opening for gas flow and a source of compressed gas.

2 . The system of claim 1 , wherein the floating structures are adapted to prevent evaporation of water in the tank based on covering the surface of the water.

3 . The system of claim 1 , wherein the floating structures are formed from Styrofoam™.

4 . The system of claim 1 , wherein the compressed gas is air.

5 . The system of claim 1 , wherein the compressed gas is carbonic gas.

6 . The system of claim 1 , wherein the tank is partitioned into a plurality of chambers, said chambers include chamber walls with gas openings that provide free gas flow between the chambers and wherein each of the chambers includes water opening through which water from surrounding environment can flow.

7 . The system of claim 6 , wherein a chamber wall that surrounds a chamber that directly communicates with the at least on duct through which the compressed gas is received, is provided with added reinforcements.

8 . The system of claim 6 , wherein the at least one duct through which the compressed gas is received branches into a plurality of ducts each of which directly communicates with one of the chambers of the tank.

9 . The system of claim 1 comprising an electricity producing turbine installed on the at least one water opening.

10 . The system of claim 1 comprising a water duct connected to the at least one water opening and extending upward therefrom, said duct adapted to provide a water opening at a height above the water opening of the tank.

11 . The system of claim 1 , wherein the tank is casted with concrete.

12 . The system of claim 1 , wherein the tank includes a floor.

13 . The system of claim 1 , wherein the tank includes walls that have a thickness that increases over a height of the walls.

14 . The system of claim 1 , wherein the tank includes walls with structural reinforcements, wherein an amount of the reinforcement provided increases over a height of the tank.

15 . The system of claim 1 , wherein the tank includes inner walls that are coated with a metal layer.

16 . The system of claim 15 , wherein a thickness of the metal layer increases over a height of the tank.

17 . The system of claim 1 , wherein the tank includes outer walls that are coated with a metal layer.

18 . The system of claim 1 , wherein the at least one duct communicating between the at least one opening for gas flow and a source of compressed gas is lined with a plurality of ribs adapted to cool the compressed gas as it flows from the source to the tank.

19 . The system of claim 1 , comprising at least one duct communicating between the at least one opening for gas flow in the tank and a pneumatic device.

20 . The system of claim 19 , comprising a heat exchange unit for transferring heat generated by the source of compressed gas to gas flowing from the at least one duct communicating between the at least one opening for gas flow in the tank and a pneumatic device.