Thanks to those gaps, crops grown under solar panels aren’t bathed in darkness. But, generally speaking, the light is more diffuse, meaning it’s bouncing off of surfaces before striking the plants. This replicates a natural forest environment, in which all plants, save for the tallest trees, hang out in the shade, soaking up any sunbeams that break through.
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This kind of setup also cools the solar panels in two ways: Water evaporating from the soil rises up towards the panels, and plants release their own water. This is dandy for the panels’ efficiency, because they actually perform worse when they get too hot. They generate an electric current when the sun’s photons knock electrons out of atoms, but if they overheat, the electrons get overexcited and don’t generate as much electricity when they’re dislodged.