Now, though, California has adopted standards that reduce those rates by 75% on average. For a farmer investing in panels, the investment looks less enticing. “The algebra or calculus — or whatever math discipline you want to reference — it just doesn’t work out the same way,” said Karen Norene Mills, vice president of legal advocacy at the California Farm Bureau, which promotes the state’s agricultural community.
Also, the study found that by fallowing land for solar panels, food production in the Central Valley dropped by enough calories to feed 86,000 people a year. But, Stid said, markets can adjust, as crops are grown elsewhere to make up the deficit. By tapping the sun instead, Stid added, growers can simultaneously help California reach its goals of deploying renewable and reducing groundwater usage.
The tension, though, is meeting those objectives while still producing incredible quantities of food. “That is always our concern about some of these pressures,” Mills said.
But this isn’t an either-or proposition: Many farmers are finding ways to grow some crops, like leafy greens and berries, under the panels. The shade reduces evaporation from the soil, allowing growers to water less often. In turn, a wetted landscape cools the panels, which improves their efficiency. “This is the compromise that’s going to allow for both energy independence and food security,” said horticulturalist Jennifer Bousselot, who studies agrisolar at Colorado State University but wasn’t involved in the new study.
Farmers are also turning livestock loose to graze under their panels. Their droppings fertilize the soil, leading to more plant growth and more flowers that support native pollinators. “The grass, it’s so much more lush under the panels, it’s amazing,” said Ryan Romack, founder of Virginia-based AgriSolar Ranch, which provides grazing services. “Especially when the sheep have been on site long-term, you can really see the added benefits of the manure load.”
Then, if a farmer decides not to replace the solar panels at the end of their lifespan — usually around 25 or 30 years — the soil will be refreshed with nutrients and ready to grow more crops. Even if a grower simply lets them sit for decades without any management, the fallowing can restore the soil’s health. “We really see solar as a collective landscape,” Stid said, “that can be sited, managed, and designed in a way to benefit both people and the planet and ecosystems as well.”
