Agrivoltaics refers to the dual operation of solar panels and agriculture on a single piece of land. Typically, an agrivoltaic site will have a photovoltaic array (a linked collection of solar panels) raised off the ground and spaced in a configuration that allows for another farming process (or processes) to co-occur. This could be growing shade tolerant crops, beekeeping, livestock grazing, cultivating mushrooms, or any other system that can be adapted to work around the photovoltaic (PV) infrastructure.
Agrivoltaic farming has the potential to mitigate several concerns related to growing food amidst an increasingly inhospitable climate and rapidly depleting fossil fuel supply. However, the environmental conditions in which a system like this can thrive are limited, and not every agricultural area will benefit from its adoption. Researchers around the globe are experimenting with this promising strategy as one of the many technologies we might employ to sustain a growing global population.
Diversifying Farmer Income
Farmers’ earnings are largely dependent on international commodity markets, meaning their income can be unpredictable month to month and year to year. Crop yields themselves are in many ways out of farmers’ hands, as unexpected weather events, pest or fungal outbreaks, or another environmental disruption could devastate a season’s harvest. The agrivoltaics model adds a second, less fluctuating source of farm income, and could act as a stabilizing factor for farmer livelihoods.
Keeping Land in Agricultural Use
The solar industry is growing exponentially in the U.S., and solar installations are expected to quadruple by 2030. Flat, unshaded ground with generous acreage is ideal for both farming and collecting solar energy, so agricultural land is an appealing spot for solar development. Unfortunately, land suitable for growing food is a finite resource, and PV expansion is encroaching on our ability to utilize it as such. Usually when farmland is converted to solar, the topsoil is stripped and panels are mounted on concrete footings. This eliminates the possibility of cultivating crops on the land for the foreseeable future, which is detrimental not only from a soil conservation prospective, but also impedes the local food supply. Agrivoltaic systems maintain soil integrity, at least partially, so land can be used to capture renewable energy while bolstering a more sustainable food system.
Plants Make Solar Panels More Efficient
A recent study from Oregon State University showed that solar panel efficiency is a function of its location’s microclimate. Too much heat collected around panels leads to lower efficiency. Agrivoltaics can help create more ideal temperature conditions to optimize energy production.
Plants lose water through their pores as they intake carbon dioxide for photosynthesis — a process called transpiration that allows plants to cool themselves and the surrounding environment. Growing crops beneath large solar arrays creates cooler conditions on the land and helps PV systems work better. The dual setup can also increase groundwater recharge and curb soil erosion, which is especially important in drought prone regions.
In 2020, Joe Biden campaigned on a plan for the U.S. to move to clean electricity by 2035. Meeting this goal will likely require significant expansion of the solar industry. Integrating this growth with farmer support could be a huge sustainability win.
While agricultural use can improve the efficiency of solar collection, PV panels themselves sometimes hinder plant growth. Vegetables that benefit from direct sunlight have been shown in some studies to produce about 60 percent of the volume they would in full sun when grown beneath solar panels. In an area with rich soil and good growing conditions, focusing on crop production might be a better use of the land. Land sparing solar energy development alternatives include urban environments, salt-affected land, contaminated land, and other areas where farming is not a viable option.
In semiarid regions like the American Southwest where farmers may grow non-native crops unadapted to water scarcity, shade from solar panels may actually be an advantage. Less direct sunlight means less water evaporation and moister soil, creating more consistent conditions for plant growth.
Agrivoltaics is not a panacea, and won’t be a sustainable solution across all agricultural landscapes. However, when implemented strategically in appropriate settings, it is a useful thread to weave into a tapestry of land and resource conservation efforts.
A research team at the University of Arizona School of Geography and Development began growing crops beneath 9-foot solar arrays in 2017 and is helping lead the way for scientific exploration of the benefits of agrivoltaics. Their test plots have shown significant productivity gains for both crop growth and solar energy collection in semiarid climates, and they are partnering with other organizations, such as The Arava Institute for Environmental Studies in the Arava Desert of Jordan and Israel, home to a climate similar to Arizona to expand their findings globally.
A solar farm called Eagle Point near Medford, Oregon began reintroducing native plants around their solar panels in 2017 and is now working with a local beekeeper to house numerous hives. Pollinator-friendly solar has been shown to benefit crop yields when projects are sited near pollinator-dependent farmland.
Jack’s Solar Garden, an agrivoltaics project in Longmont, CO, is home to multiple variations of agrivoltaics including crop production, pollinator habitat, and pasture grazing. Jack’s is the largest commercially active agrivoltaics system in the U.S., and it generates enough electricity to power more than 300 homes.
The American Solar Grazing Association is a nonprofit that facilitates research and best practices for sheep farmers and solar developers combining forces on sustainable grazing land. Sheep are well suited to solar grazing because of they benefit from the shade of solar panels and they are resourceful foragers. Solar grazing reduces or eliminates the need for mowing at solar sites, and allows for lower impact livestock care.
One of Farm’s primary goals is cultivating land with lasting sustainability and value. We prioritize projects that are seizing upon the rapid expansion of clean energy without compromising land restoration and conservation. We are committed to pursuing agrivoltaic land in climate appropriate regions, and working with farmers and solar development partners who share our values. If you are interested in getting involved with an agrivoltaic project, or starting one of your own, please get in touch!