Heavy precipitation that can damage crops is also on the rise, since a warmer atmosphere holds more moisture. \u201cIn times when there is extreme heat or extreme precipitation, by protecting plants in this manner, it can actually benefit them,\u201d says Madhu Khanna, an economist at the University of Illinois, Urbana-Champaign, who also won funding from the USDA\u2019s new agrivoltaics grant. \u201cSo that’s another factor that we want to look at.\u201d\u00a0<\/p>\n
Khanna will be studying what the ideal solar array might be for a particular crop, for instance, if it needs bigger or smaller gaps between panels to let sunlight pass through. Height, too, is an issue: Corn and wheat would need taller panels, while shrubby soybeans would be fine with a more squat variety.\u00a0<\/p>\n
Thanks to those gaps, crops grown under solar panels aren\u2019t bathed in darkness. But, generally speaking, the light is more diffuse, meaning it\u2019s 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.\u00a0<\/p>\n
![\"Image](\"https:\/\/media.wired.com\/photos\/5a729f25234aa351bd9b5a75\/master\/w_775%2Cc_limit\/Guides_GlobalWarming.jpg\")
<\/picture><\/span><\/div>\nThe WIRED Guide to Climate Change<\/h3>\n
The world is getting warmer, the weather is getting worse. Here’s everything you need to know about what humans can do to stop wrecking the planet.<\/p>\n<\/div>\n<\/div>\n<\/div>\n
Barron-Gafford has found that a forestlike shading under solar panels elicits a physiological response from plants. To collect more light, their leaves grow bigger than they would if planted in an open field. He\u2019s seen this happen in basil, which would increase that crop\u2019s yield. Barron-Gafford has also found that the pepper Capsicum annuum<\/em>, which grows in the shade of trees in the wild, produces three times as much fruit in an agrivoltaic system. Tomato plants also grow more fruit. This is likely due to the plants being less stressed by the constant bombardment of sunlight, to which they\u2019re not evolutionarily adapted.<\/p>\n But every crop is going to be different, so scientists have to test each to see how they react to shade. \u201cFor example, we probably wouldn’t recommend that somebody plant summer squash directly in the deepest shade, directly under a panel,\u201d says Mark Uchanski, a horticultural scientist at Colorado State University who\u2019s studying agrivoltaics and tested that exact scenario. \u201cThe better location for that might be further out toward the edges where it’s more likely to get a little bit more sun, because we did see a yield decrease in that case.\u201d\u00a0<\/p>\n While setting up the panels entails some up-front costs, they might actually make farmers some money, as Kominek told Grist in this 2020 story before his panels were in place. They\u2019d produce energy to run the farm, and the farmer can sell any surplus back to a utility. And since some plants\u2014like those salsa ingredients in Barron-Gafford\u2019s experiments\u2014will use less water, that can reduce irrigation expenses. \u201cIf we can actually allow farmers to diversify their production and get more out of the same land, then that can benefit them,\u201d says Khanna. \u201cHaving crops and solar panels is more beneficial for the environment than solar panels alone.\u201d\u00a0<\/p>\n 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\u2019 efficiency, because they actually perform worse when they get too hot. They generate an electric current when the sun\u2019s photons knock electrons out of atoms, but if they overheat, the electrons get overexcited and don\u2019t generate as much electricity when they\u2019re dislodged.\u00a0<\/p>\n![\"garden\"](\"https:\/\/media.wired.com\/photos\/6165ee69ff57abbf423bc523\/master\/w_1600%2Cc_limit\/Science_inline_B2-agrivoltaics-site.jpg\")