Harnessing Evaporation Could Yield More Power than Wind, Study Shows

Using the energy produced by evaporating water, researchers at Columbia University have shown that they can power a small toy car and a flashing light — the first step, they say, in harnessing an immense energy source that could rival power production from wind and waves. The devices they built use bacterial spores that can absorb humidity and, in doing so, expand and contract with enough force to push and pull pistons and drive a rotary engine. The spores pack more energy, pound for pound, than other materials used in engineering for moving objects, said researcher Ozgur Sahin, who co-authored the study published in Nature Communication. When evaporation energy is scaled up, he says, it could one day produce electricity from giant floating power generators that sit on bays or reservoirs or rotating machines like wind turbines that sit above water.