Lake piston

The Lake Piston is a relatively new concept for a renewable energy system. The principle behind this system is the decrease in density of water after its fusion point is reached. If the water were to be confined in a space, this expansion could be harnesed by means of a piston. Increasing the temperature of the water would then reduce its density, hence volume allowing the cycle to be complete. The process behind this system is similar to that of the Stirling Engine. By utilising ambient temperatures, it could conceivably be possible to apply this process on a larger scale (i.e. a lake) using the seasonal variations in temperature to drive this process.

A proof of concept device was built near Leipzig, Germany by Dr. Nate Riolm. "This device should revolutionize renewable energy systems around the world". According to Dr. Riolm, the lake piston has a much greater reliability than most other systems. This is due to a reduction in motion. "By reducing the number of revolutions to one a year, we can reduce the tolerances for it, as well as maintenance. One problem that many oscillating systems encounter is the vibrational loads introduced. We've virtually eliminated this".