“Agrivoltaics” is the use of land for agriculture and solar energy generation. Sometimes referred to as agrophotovoltaics or dual-use solar, the aim of the concept is to help keep farmland in production, in turn easing the land-use conflict that often surrounds solar installations in rural America.
According to the US Department of Energy, solar accounted for 5.77% of US electricity generation in the first half of 2023. However, the agency forecasts that solar could supply as much as 40% of US electricity by 2035.
Expanding solar generation to such a degree would obviously require more land use. To reach the 40% share of electricity that the DOE forecasts, it would require a land area equivalent to 0.5% of the contiguous US surface area. The challenge is finding land that is suitable for solar. It is best distributed on flat, unobstructed land that gets plenty of sunshine, which describes much of the Midwest’s farmland.
Agrivoltaics is intended to be a system in which agriculture and solar energy production compliment one another. One benefit to land owners is obviously the opportunity to diversify their income stream. Proponents of agrivoltaics say it can also benefit crop and livestock production.
According to research cited by the DOE, agrivoltaic systems in some locations can reduce crop yields but under ideal conditions, a symbiotic ‘cooling’ relationship occurs. The microclimate created by solar panels can increase yields for some crops, while the presence of plants under the panels helps increase their efficiency. The research suggests that overall, combined energy and crop production from agrivoltaic systems could increase land productivity by as much as 70%.
Another form of agrivoltaics integrates livestock and pastures, commonly referred to as “solar grazing.” Traditionally, the grasses that would grow up between solar panels need to be mowed to prevent the plants from shading the panels and reducing their efficiency. However, when sheep or goats can be used, the costs associated with mowing are eliminated for the solar company, while producers can benefit from an added revenue stream to graze their animals at these sites.
The DOE actually has an ongoing agrivolatics research project called “InSPIRE” (Innovative Solar Practices Integrated with Rural Economies and Ecosystems) which aims to “unite field research across the US with advanced modeling and analysis to provide foundational and actionable data on agrivoltaics and low-impact solar development.” The project also investigates region-specific benefits and tradeoffs to ecosystems, grazing habitat, and crop production.
A new project between Iowa State University and Alliant Energy also aims to provide important insights about the use and limitations of agrivoltaics. The 1.375 MW “Alliant Energy Solar Farm” will deploy 3,300 solar panels on university land that is already used for animal science teaching and research farms. Horticulture and agriculture students will plant crops to study how they perform under solar arrays of various heights and configurations. Meanwhile, engineering students will review solar production data to see how various crop plantings impact solar production.
Researchers plan to explore which crops thrive in a modified solar microclimate. They plan to plant vegetables, fruits, and pollinator habitats. They also intend to study how solar site maintenance impacts cultivation. “Growing these types of crops under and around a solar farm on a scalable basis is different than just growing them. We want to demonstrate that’s possible,” said Ajay Nair, lead principal investigator.
The project, which received a $1.8 million four-year grant from the DOE, is expected to be fully operational in early 2024. Learn more about the project HERE. You can also learn more about pairing agriculture and solar at the Energy Department HERE. (Sources: USDA, DOE, EnergyInsider, ISU)
