October 19, 2023
The use of land for both agriculture and solar photovoltaic energy generation can be mutually beneficial for both farmers and solar developers. Solar energy systems, with crop production and animals grazing all at once! Combining these things can help solve two problems, mitigating climate change with solar and feeding the population with crops.
The practice of agrivoltaics started in France in 2011 at the French National Institute for Agriculture, Food, and Environment (INRAE) by Christian Dupraz. In 2018, projects started in the U.S. at universities in Oregon, Arizona, and Colorado. The most well-known operational site of agrivoltiacs is at Jack’s Solar Garden in Longmont, Colorado.
There are 300+ agrivoltaic installations in the U.S. Putting crops under solar modules has agricultural benefits. These benefits include shaded land to help retain moisture for plants, decreasing water demand by 12%-34% (study by Christian Dupraz). Using the system in a drought-prone region could help reduce water irrigation input by 19%-47%.
Professor Chad Higgins at Oregon State reported that agrivoltaic systems are shown to increase land productivity for farmers by 60% to 70% and increases the value of the energy production system by 30%. Soil health has been cited as another benefit of agrivoltaic projects.
During a particularly hot summer in Germany in 2018, Fraunhofer Institute released a report showing that potatoes grown under the shade of solar panels received a land-use efficiency of 186%, compared to potatoes grown next to the solar energy system.
Greg Barron-Gafford at Arizona State found larger heads of broccoli and an increased seasonal production of tomatoes harvested in August in the arid regions of Arizona. He also found that basil, lettuce, melons, and chard were able to grow under 10-foot elevated solar panels.
Pollination is required for successful food production, and growing a bee pollinator habitat within agrivoltaic areas is a growing trend. One of the longest-running examples of this is the InSPIRE project.
“InSPIRE’s database currently covers 270 reported U.S. solar-pollinator projects with a combined energy production of more than 1.2 GW and occupying just over 6,600 acres.” – Michael Schoeck.
Pollinator Habitat Aligned with Solar Energy (PHASE) was started in 2021 by the Department of Energy to find the economic and ecological outcomes of pollinator-friendly solar projects in the Midwest.
Livestock Grazing and Solar
Another use of agrivoltaic land is livestock grazing. Sheep, for example, provide useful vegetation management. The discovery that sheep provide valuable vegetation management, has brought a new demand for sheep in the U.S.
Multi-thousand-acre projects in Texas require 1,800+ sheep to maintain vegetation growth, a 24-inch maximum clearance is required for utility solar operations, and the sheep help with that! The use of sheep reduces the number of mowing needed for the project from an average of 5 to just 3.
Loran Shallenberger at Silicon Ranch has seen around 20% savings toward operating expenses by using sheep grazers. Some developers have budgets near $1 million set aside for conventional lawn mowing, so 20% of that is a significant number.
U.S. Senators Martin Heinrich (D-NM) and Mike Braun (R-IN) introduced federal legislation in mid-2023, called the Agrivoltaics Research and Demonstration Act of 2023. The Department of Agriculture and Department of Energy gave $75 million in subsidies to research agrivoltaics projects.
The USDA will distribute new funding of about $15 million between 2024 and 2028 to better support agrivoltaic projects.
Multi-use projects can serve multiple purposes and create additional value for all parties involved. More solar developers are starting to see that agrivoltaics can be beneficial. Agrivoltaics is starting to spread around Illinois and is providing proof that this can work! While it may take a bit of time to determine the proper cropping of these projects, we already know that advanced conservation can benefit crops and farmers.
According to the Great Plains Institute, more than 5 million acres in the U.S. could be suitable land for agrivoltaics. The U.S. currently has over 43% of land mass used for agriculture, meaning there is plenty of opportunity to combine solar with agriculture.