Agri-Voltaics
Combining Green Energy and Agriculture!
Agrivoltaics is the use of land for both agriculture and solar photovoltaic energy generation. It’s also sometimes referred to as agrisolar, dual use solar, low impact solar. Solar grazing is a variation where livestock graze in and around solar panels. This system looks at agriculture and solar energy production as compliments to the other instead of as competitors. By allowing working lands to stay working, agrivoltaic systems could help farms diversify income. Other benefits include energy resilience, and a reduced carbon footprint.
A symbiotic ‘cooling’ relationship occurs when growing crops (or native grasses and forbs) under solar panels. Together, each helps keep the other cool. While all crops need sunlight to grow, too much can cause some to get stressed, especially cool season plants such as brassicas. Plants growing under the diffused shade of photovoltaic panels are buffered from the day’s most intense rays. Shade reduces air temperature and the amount of water evaporating from soils; a win-win for both plants and farm workers on hot summer days. The plants in turn give off water vapor that helps to naturally cool the photovoltaic panels from below, which can increase panel efficiency.
Agrivoltaics in the Northeast
The largest agrivoltaics site in the U.S. is on a blueberry farm in Rockport, Maine. This new 10-acre, 4.2-megawatt project is the first of its kind in the state, and will offer critical insights and experience. Researchers from University of Maine Cooperative Extension are evaluating the impact of panel installation on the blueberry plants. They will also see how the crop fares over time under the solar array.
Another form of agrivoltaics seen across the Northeast integrates livestock and pastures. This concept is commonly referred to as ‘solar grazing.’ It has taken off in recent years as a win-win-win for farmers, solar companies, and the environment. 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 can be used, the high maintenance costs associated with mowing are eliminated for the solar company. At the same time, local shepherds can benefit from an added revenue stream to graze their sheep at these sites. Removing mowing operations not only keeps grassy areas safer for wildlife (i.e., nesting ground birds), but means less fuels and emissions too.
Agrivoltaics Research
The U.S. Department of Energy is supporting solar development and agriculture with their InSPIRE program. This program is managed by the National Renewable Energy Laboratory (NREL). It seeks to improve the mutual benefits of solar, agriculture, and native landscapes. Currently, there are 22 projects sites across the U.S. These bring together a wide array of researchers, farmers, and industry partners.
NREL research projects located in the Northeast:
University of Massachusetts Amherst: Researchers are studying the effects of co-locating solar energy panels and agriculture operations at up to eight different farms across the state. This research will help farmers and communities make informed decisions about solar.
Cornell University: Researchers are looking at the benefits of pollinator-friendly plantings on solar farms. One goal is to see if wildflower plantings on solar sites can increase pollinator populations. Another is to see if wildflower plantings on solar farms encourage pollinators to visit crop flowers. Other Cornell research is looking at how sheep grazing may influence pollinator habitat and sequestration of soil carbon.
Other regional agrivoltaic research projects of note:
Rutgers University: In June 2021 the Dual-use Solar Act was passed in New Jersey. This act set up a pilot program “to enable a limited number of farmers to have agrivoltaic systems on their property while the technology is being tested, observed and refined.” Funds also went to the New Jersey Agricultural Experiment Station to build and study agrivoltaic systems on their research farms.
University of Vermont: This past fall, UVM Extension’s Center for Sustainable Agriculture put on a workshop called, Solar Energy in Vermont's Working Landscape. The event brought together experts and stakeholders to address existing practices and barriers to solar grazing adoption as well as requirements for long-term success in the state. Before this, the Center’s pasture program worked with Vermont Agency of Agriculture, Food & Markets and Two Rivers-Ottauquechee Regional Commission. They developed guides for how to “balance the needs of community and farm-scale energy needs with a shared commitment to protecting agricultural lands.”
While a lot of research is underway, many questions about agrivoltaic systems persist. Various research and demonstration sites around the country are working to find answers to questions like: What are the long-term impacts of solar energy infrastructure on soil quality? What crops, in what regions, are best suited for photovoltaic systems? How can both crop and energy systems be optimized? How will livestock (and wildlife) interact with solar energy equipment? What types of business agreements will work best between a solar developer or company and agricultural producer or landowner?