[SagelyGuru]

It would be more efficient to use a pressure tank half filled with water and use water pump and Pelton turbine for the energy cycling.

[nine_k]

Water is practically incompressible.

If you wanted to compress the air 10x the atmosphere pressure, when it takes 10% of the normal volume, you would have to fill the tank with water for more than 90%.

Without water, you can compress air 10x and put 10x more of it into the same pressurized tank.