Evaporation is a key component of the Earth’s water cycle, and one of the world’s most dominant forms of energy transfer—and it’s believed that as the climate warms, evaporation rates will increase and result in more moisture in the lower atmosphere. Yet the power of evaporation has rarely, if ever, been utilized for energy generation. But one lab at Columbia University is seeking to change that. By harnessing the natural properties of spores—and their responses to humidity—they have created two devices that generate renewable energy from evaporation. The lab hopes that one day these devices could be scaled up to produce electricity from large floating power generators, or from rotating machines akin to wind turbines that sit above water.