Solar power is a huge benefit for individuals, businesses, the nation and the planet. It takes free and inexhaustible energy from the sun and converts it at virtually no cost into electricity to be used for the energy needs of a household or business, or to increase the efficiency and reliability of the larger power grid. Solar power produces no emissions and we’re not expected to run short of it for about the next five billion years.
Solar arrays also deliver a great benefit to landowners like farmers, who lease all or portions of their property for large solar arrays that generate clean energy back into the regional electric grid while delivering income to the landowner. For farmers, this is a great way to diversify their income stream and comes with an added benefit.
What is Agrivoltaics?
Solar farms, as they’re known, are large arrays of solar panels, but they can also actually serve as what we more commonly call farms, or at least as places where plants and grasses grow. This is known as agrivoltaics, combining agriculture with voltaics, or the production of electricity.
Agrivoltaics involves employing the area under and around the solar panels to grow shade-friendly crops, grasses for grazing animals or pollinating plants. The agriculture and solar power work in a symbiotic relationship. Shaded plants need less water because they are kept cool during hot, dry weather, which we are seeing more of with climate change. Shade from the panels also keeps crops warmer at night by blocking the escape of heat.
Conversely, the crops absorb heat during the day, cooling the back of the solar array and increasing its efficiency. A 2019 study by the Universities of Arizona and Maryland found crop yields were double to quadruple beneath solar panels and dramatically reduced their water consumption. The solar installations were more effective too, though not so significantly.
Agrivoltaics for Yams, Lettuce, Sheep and More
Agrivoltaics work best for plants that grow well in partial shade, like peanut, alfalfa, yam, taro, cassava, sweet potato, and lettuce. It is also great for growing grasses that sheep, cattle and goats eat. This feeds the livestock who serve as lawnmowers in and around the panels.
Goats, pigs, horses and cows can damage panels, which must be built higher off the ground to accommodate them. Sheep are a good fit for an agrivoltaic arrangement because they are smaller and docile. The American Solar Grazing Association (yes, there is such a thing!) has found that grazing livestock can slash vegetation management costs by 30%.
When panels are raised six or eight feet off the ground, farmers can drive tractors under and around them, allowing for efficient harvesting and larger installations.
Alder Energy Systems is building a solar installation on about a dozen acres of a 290- acre farm in Maryland. The plan is to plant native grasses conducive to sheep grazing. The farmer gets guaranteed income and a place for his sheep to eat and stay cool.
Even communities that are less hospitable to solar farms are warming to this dual use scenario because it helps keep farms profitable and produces green energy. Best practices are just now being developed as agrivoltaics is in its early stages, so this win-win is only going to get better.
