Renewable energy from evaporating water

New York: Can the energy of evaporating water be harnessed to propel self-sufficient devices or produce electricity? A new experiment raises hopes. Columbia University scientists report the development of two novel devices that derive power directly from evaporation, a floating, piston-driven engine that generates electricity causing a light to flash and a rotary engine that drives a miniature car.

When evaporation energy is scaled up, the researchers predict, it could one day produce electricity from giant floating power generators that sit on bays or reservoirs, or from huge rotating machines akin to wind turbines that sit above water."Evaporation is a fundamental force of nature.

It is everywhere, and it is more powerful than other forces like wind and waves," said lead author Ozgur Sahin. Sahin found that when bacterial spores shrink and swell with changing humidity, they can push and pull other objects forcefully. They pack more energy, pound for pound, than other materials used in engineering for moving objects.