Investing in solar energy will require expansion over land. Like windmills, solar panels need space, creating what has been dubbed “energy sprawl.” Even as a fraction of the U.S. energy portfolio, solar power has already led to land-use conflicts, with proponents of solar starting to spar with farmers over land.

Agrivoltaics help to solve that spatial dilemma. They allow a given area to harvest the sun not only once, but twice — as fuel for crops and as a source of renewable energy. But space-saving isn’t all that has sparked the interest of researchers and advocates across the world, from the U.S. to Western Europe and Japan. Another kind of symbiosis can occur, with surprising benefits we are only just beginning to understand—an untapped synergy that may have the potential to transform the way we produce both food and energy. In his research on agrovoltaics in Arizona, Greg Barron-Gafford has identified some benefits to agrovoltaics.

In his 2019 study of jalapenos, cherry tomatoes, and chiltepines (a desert chile native to the U.S.), Barron-Gafford found that agrivoltaic panels produced 3 percent more energy during the May-through-June growing season and 1 percent more overall due to decreased temperatures underneath the panels, which increased their efficiency.

But the benefits weren’t only on the energy-efficiency side. His simple system—just solar panels lofted above plants—also helped the crops, which needed far less water to grow. This was due to cool shade under the solar panels. “If you spilled your water bottle in the shade versus out in the sun, where’s it going to stay wet longer? In the shade,” he said. “So we’re just using these oh duh principles to try to make a more sustainable food system.”

The shade also conferred another significant benefit, one that may prove tantalizing for farmers focused on yield: The presence of solar panels  increased yield for two of the three plants he studied. Tomato production doubled, with 65 percent more water efficiency. Chiltepin production tripled. Jalapeno production was static, yet with water efficiency 157 percent greater — a win in a region embroiled in historic drought.

There has been some variability in the success of experiments with agrovoltaics. In Minnesota, solar panels shading the cattle of a rotational grazing pasture have successfully lowered animal heat stress while powering a milking parlor. In Belgium, an agrivoltaic potato field showed cooler microclimates below panels and less evaporation, as well as larger leaves with “adapted light harvesting capability.” But in other locations, the results are more mixed. In Massachusetts, numerous cranberry bog farmers have adopted agrivoltaics, hoping that solar energy will provide an additional source of revenue and offset plummeting prices—though some worry that the crop won’t respond as well to shade, the Associate Press reports. In Italy, spinach yields decreased in one study. Still, its researchers observed more efficient photosynthesis and greater protein production.

Read the full article about agrovoltaics by Chris Malloy at The Counter.