Patent ID: 8065873

Claim:
An energy storage and recovery system comprising: a cylinder comprising a first chamber having a moveable piston disposed therein and in selective communication with an energy source through a mechanical linkage, the mechanical linkage configured to transmit a power of expanding gas, out of the cylinder; an air tank in selective fluid communication with the first chamber through a first valve; an air source in selective fluid communication with the first chamber through a second valve; a liquid source in selective fluid communication with the first chamber through a third valve; and a controller in electronic communication with, and configured to operate, system elements in one of the following states: an intake step wherein the first valve is closed, the second valve is open, and the third valve may be open or closed; a compression step wherein the piston is in communication with the energy source, the first and second valves are closed, the third valve is open or closed, and then the first valve is opened upon compression of the air in the chamber by the piston, an expansion step wherein the piston is not in communication with the energy source, the first valve is opened, the second valve is closed, and the third valve may be open or closed, such that the air expands in the chamber to move the piston, and then the first valve is closed as the air continues to expand, and an exhaust step wherein the piston is not in communication with the energy source, the first valve is closed, the second valve is open, and the third valve may be open or closed; and; wherein the controller is configured to determine an operational parameter in order to maintain a temperature of the air in the first chamber within a range.