Patent ID: 6964165

Claim:
An apparatus for recovering energy from a compressed gas, comprising: a piston-cylinder assembly that is mounted for movement in a body of water between a first lower position and a second upper position, said piston-cylinder assembly comprising; a cylinder positioned in said tank; and a piston disposed in said cylinder and cooperating with said cylinder so as to define an expandable chamber therewith; a pontoon disposed in said tank to receive the piston-cylinder assembly; pressure coupling means, positioned proximate to said lower position, for introducing a compressed gas into said expandable chamber; and energy recovery means, connected to said piston-cylinder assembly, for recovering energy from said piston-cylinder assembly as said piston-cylinder assembly floats from said first position to said second position, and wherein said energy recovery means is further constructed and arranged to recover additional energy from said piston-cylinder assembly as said piston-cylinder assembly returns by sinking to said first position.