Could Solar Energy Change Farming?
According to the U.S. Department of Energy’s SunShot Vision Study, solar energy capacity could reach 329 gigawatts in the year 2030, which would require approximately 1.8 million acres of land. This represents less than .1 percent of total land area in the contiguous United States. In an effort to continue innovations in the solar space, the concept of agrivoltaics has surfaced. Agrivoltaics puts unused land to use in a new way, by merging solar power with conventional agriculture to develop the same area of land.
Interestingly, solar panels don’t work efficiently in some of the hottest places on Earth. But with agrivoltaics, planting vegetation under solar panels can make the panels work better.
What is Agrivoltaics?
Adolf Goetzberger, founder of the Fraunhofer Institute for Solar Energy, and Armin Zastrow pioneered the idea of agrivoltaics in 1981. The idea was that landowners wouldn’t need to choose between using land for solar energy generation or agriculture, but instead, use it for both.
Essentially, crops planted under or around solar panels reduce the surrounding temperature, lessening what’s called a heat-island effect. As water transpires through the plants’ leaves, the panels are cooled by the evaporation, which allows for more of the sun’s energy to be converted to usable electricity.
- Place solar arrays on the ground and allow crops to grow in the space between them.
- Mount solar arrays on stilts with crops growing beneath them.
- Place panels on the roof of a greenhouse.
Benefits of Agrivoltaics
Both solar developers and agricultural land managers can benefit from co-locating solar and crop production. Solar developers reap the benefits of reduced installation costs, reduced upfront and legal risks, and a potential increase in photovoltaic performance. Agricultural land managers reap the benefits of reduced electricity costs, diversification of revenue stream, control of wind and soil erosion, marketing opportunities to sustainability-mindful audiences, and the ability to maintain crop production.
Cattle and livestock farmers can also benefit from this technology. Keeping a herd of sheep or livestock on the development can help control vegetation height and significantly reduce operation costs for developers. This fosters a mutually beneficial relationship, where developers provide grazing land and sheep provide low-cost vegetation control.
A 2018 study by researchers at Oregon State University found that solar panels could even increase productivity on pastures that are not irrigated and water-stressed. The study found that plants and grasses are able to thrive under the shade of the solar panels, allowing the shaded areas to be 328 percent more water efficient and maintain higher soil moisture. This leads to twice as much grass under the arrays compared to unshaded areas.
What’s Next for Solar Farming?
Today, companies are testing large-scale agrivoltaic sites around the world. The Fraunhofer Institute for Solar Energy Systems is testing an elevated solar array system over a one-third hectare section of cropland in Germany. The solar panels are bifacial PV modules that catch both rays from above the refracted rays from below. Underneath, they are growing potatoes, clover, celery, and wheat. From this particular study, land use efficiency increased by 60 percent.
With more land being devoted to solar energy production, the idea of making those areas pollinator-friendly makes a great deal of ecological and economic sense. Replacing turfgrass and gravel with native and crop vegetation as the go-to bedding for solar fields can improve the health of pollinators, who are currently threated by habitat loss, pesticide poisoning, poor nutrition, and a number of other factors.
Researchers continue to test the usefulness of agrivoltaics in different latitudes and climates throughout the world. The ultimate goal is to advance renewable energy production while providing a better crop yield to agriculture.