The agricultural benefits of solar power installations

The Solar Energy Industry Association (SEIA), the leading trade association of the solar energy industry in the U.S., of which Blymyer is a longstanding member, has concluded that the building of large-scale solar projects is a boon to the agricultural industry. Despite conventional wisdom to the contrary, colocating solar with agriculture (known as agrivoltaics or dual-use solar) is actually beneficial to both industries.

Here are some of SEIA’s specific findings:

• Solar accounts for minimal farmland – Although renewable energy critics have claimed that ground-mounted solar farms are taking up large portions of viable agricultural land, expanding urban areas and residential development—not renewable energy facilities—have accounted for nearly all lost farmland. Case in point: Over the last decade, while North Carolina rose to become the number two state in the U.S. in solar installations, it lost one million acres of cropland to development and housing, yet only one percent of that total was due to solar development.
• Solar allows land to recover – Soil can actually be improved by planting native grasses/pollinators and letting the soil lie fallow for an extended period of time. After the solar panels are installed, native vegetation—often friendly to bees and other pollinators—is planted. The deep roots of the planted native vegetation retain more water than turf grass and gravel during heavy storms and periods of drought. They also help retain topsoil and improve soil health over time, even in “brownfield” areas with polluted soils.
• Solar can offset power required for pumping – It can also provide electricity to remote irrigation systems, delivering substantial tax revenue to local communities. Detailed data collection in North Carolina shows that local tax revenues were up to 2,000 percent after the state’s solar expansion.

The National Renewable Energy Laboratory (NREL) highlights two other advantages of the coexistence of solar and agriculture:

• Solar can be beneficial to crop production – Certain crops thrive under the partial shade of solar installations, which reduces the amount of direct sunlight, changes the microclimate (making days cooler and nights warmer) and increases soil moisture levels. In arid climates, for example, there might be higher yields with lower watering requirements. In extremely wet environments, panel spacing and other factors play an important role in managing on-site water distribution and eventual yields.
• Solar can coexist successfully with grazing livestock – Foraging livestock can help control the growth of vegetation under solar arrays, a factor that can be considered at the early phases of solar planning and installation by seeding appropriately and raising modules, wires, and electrical boxes. Livestock can reduce the maintenance costs of trimming beneath panels and reduce the need to use herbicides. In addition, animals also benefit from the shade provided by solar panels.