Forget the sun and wind — evaporating water could be the next big source of renewable energy, said James Temple at Technology Review​. So-called evaporation-driven engines "generate power from the motion of bacterial spores that expand and contract as they absorb and release air moisture." Evaporation continues 24/7, so the engines, which sit on the water's surface, could provide power nonstop — unlike solar panels.

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The technology is still in a prototype phase, but a new study in the journal Nature Communications notes that the power available from natural evaporation in lakes and reservoirs in the continental U.S. could meet 70 percent of the nation's needs. If even a small amount of that energy were tapped, says study co-author Ozgur Sahin of Columbia University, evaporation-driven engines "could make a significant contribution to clean-energy and climate goals."