Agrivoltaics: Solar Panels and Agriculture
By Mike Buza
Agrivoltaics is not an entirely new concept, but it is not widely known or understood. Sometimes called dual use, agrivoltaics means solar developments and farming operations occupy the same land. Agrivoltaics are growing quickly. According to the National Renewable Energy Laboratory, (NREL) 35,157 acres of land were used in agrivoltaics nationwide in November 2023.https://www.nrel.gov/docs/fy24osti/87786.pdf Currently, 65,798 acres are in agrivoltaic production according to the NREL.https://openei.org/wiki/InSPIRE/Agrivoltaics_Map The most common agricultural practices under solar arrays are sheep grazing and plantings for honey production. Other uses include raising fruits and vegetables, grazing cattle and some row crops. The increasing use of agrivoltaics is helping promote wider acceptance of solar developments.
In Michigan, site requirements for solar facilities approved by the Michigan Public Service Commission (MPSC) favor pollinator habitat underneath the arrays. Wildlife, including insects, birds and small mammals, flourish under large solar arrays where native plants are used. Siting criteria set under Michigan’s clean energy laws discourage the use of pesticides, allowing pollinators to flourish. Farmers frequently place bee hives to collect honey around solar panels, with the pollinator habitat underneath benefiting many crops in proximity to the habitat.
Growing crops under solar arrays benefits some types of fruits and vegetables which have a limit to how much sun is beneficial for their growth, called the light saturation point.https://agsci.oregonstate.edu/newsroom/sustainable-farm-agrivoltaic Beyond the saturation point, the plants lose moisture and may suffer. Michigan State University found that tomatoes grown under solar panels produce double the amount grown in unshaded areas. https://news.jrn.msu.edu/2021/04/crops-grown-under-solar-panels-and-pollinator-habitats-could-be-wave-of-the-future/
Solar panels, in turn, benefit from the vegetation under them. The vegetation, through a process called transpiration, helps to cool the panels and increase their efficiency. https://theconservationfoundation.org/agrivoltaics/
Besides pollinator-friendly habitats, grazing sheep is the next most common farm commodity under solar panels. Sheep help maintain the vegetative growth under the solar panels, doing a better job of maintaining the vegetation at a lower cost than machines. Sheep are more in harmony with the concept of green energy than carbon belching machines to maintain the vegetation around solar. If regenerative farming is used in raising the sheep, the land can also sequester carbon. Other states, such as Texas, use sheep for vegetation control in large-scale solar development. https://www.canarymedia.com/articles/solar/6-000-sheep-will-soon-be-grazing-on-10-00-acres-of-texas-solar-fields
Although pollinator habitat and sheep are the most common agricultural crops raised under solar panels, many other crops have been planted in conjunction. Research has shown that more than 80% of people are inclined to support solar development if agriculture is practiced on the same land. https://link.springer.com/article/10.1007/s44173-022-00007-x
To encourage more agrivoltaic development, Michigan must also pass laws to enable community solar developments. Community solar means a number of individual electric ratepayers subscribe to a moderate-size solar development, receiving credit for the electricity produced by the facility. Electricity developed from solar energy is deducted from the member’s electric bill. Community solar developments are typically from five to twenty acres. Many fruits and vegetables are grown on these moderate plots of land. https://www.canr.msu.edu/news/agrivoltaic-opportunities-grow-crops-in-solar-energy-systems These moderately sized solar developments with agriculture underneath are called community solar gardens. Community Solar Gardens: Expanding Your Farm's Revenue Streams
Environmental groups have been advocating for the enactment of community solar laws for several years, but investor-owned utilities in the state have blocked their passage. The community solar bills are sponsored on a bipartisan basis, which should make them easier to pass. We need your support. Please contact your state legislator and ask them to support the community solar bill.
If you have any questions or comments, or would like further information, please contact Mike Buza at theoriginalzuba@yahoo.com. Mike is also available to arrange a seminar presentation on the topic by contacting him at his email address.