The U.S. Department of Energy’s National Renewable Energy Laboratory’s (NREL) Lead Energy-Water-Land Analyst Jordan Macknick and co-authors from the universities of Arizona and Maryland investigated the potential benefits of these agrivoltaic systems on food production, energy productions, and water irrigation.
The goal of these agrivoltaic systems is to maximize crop yield, minimize water use, and produce resilient and renewable energy.
Researchers tested the concept by planting three common plants, representing three different dryland environments, beneath the photovoltaic panels. During a three-month growing season, researchers monitored light levels, relative humidity, air temperature, soil temperature, and moisture at the soil level.
These systems are beneficial to both the agricultural and energy sectors because of water scarcity and extreme weather event concerns. Having a resilient global energy system is more important than ever. Wind and solar photovoltaics are another way the energy sector is working to satisfy these concerns. Unfortunately, studies of these systems have found that ground-mounted PV installations with gravel can lead to increased temperatures, which can negatively affect the panels. Swapping out the gravel for vegetation can help counter the heat.
It doesn’t have to be an either-or choice. For all our agriculturally productive land, let's help PV developers and farmers plan out these solar projects so that farmers can get under the arrays and continue to work the land for the next 20 or 30 years."
—Gerry Palano, energy program coordinator, Massachusetts Department of Agriculture
Across the board, the crops under the solar panels saw an increase in water-use efficiency, and one of the crops produced three times greater than the control. Because the PV panels reduced the direct sunlight exposure on the plants below, air temperature went down during the day and increased at night, allowing the plants below the panels to retain more moisture than the control crops growing in open-sky planting areas. The PV panels were significantly cooler in the daytime hours than the control, allowing for better performance overall.
These agrivoltaic systems could offer positive outcomes across the board by increasing crop production, reducing water loss, and improving the efficiency of PV arrays. Building resilient food production and energy generation systems is more important than ever, and these systems help achieve that.