Solar Panels Can Cool Crops and Workers, Modeling Study Finds

Photovoltaic technology, commonly seen as bulky solar panels on solar farms, is expected to become a dominant energy source by 2050. But these panels are often installed on land that could otherwise grow crops. Agrivoltaics, the practice of planting crops around or beneath solar panels, aims to make such land more productive. Earlier studies found panels can shade crops and raise soil moisture, but most research examined only one factor at a time.

A study published in Journal of Advances in Modeling Earth Systems presents a new model that simulates microclimates, the local climate conditions created near the ground, beneath solar panels, and the heat stress workers might face in real conditions. The model tracks interactions among solar panels, crops, soil, air and water movement, and carbon dioxide uptake, following how energy, momentum and mass move through the system. Researchers checked its predictions against real site data, including leaf temperatures from Davis, California, and soil temperatures from Chicago City, Minnesota.

The team then applied the model to a hypothetical agrivoltaic tomato farm, using weather data from a hot, humid day in Princeton, New Jersey, a location representative of the densely populated Mid-Atlantic region, where food and energy are both in high demand. Compared with tomatoes grown in an open field, those grown under solar panels had leaf temperatures 1.84 degrees Celsius cooler during the day overall, and up to 7.56 degrees Celsius cooler during peak afternoon heat, cutting water loss through evapotranspiration, the process by which plants release water vapor into the air, by 22.4 percent.

Although the simulated crops received 47 percent less sunlight, their carbon uptake fell by only 31 percent, as cooler conditions offset the added shade. The panels were 5.6 degrees Celsius cooler in daytime than panels over bare soil, recovering about 15 percent of the efficiency lost to heat. Perceived temperature for people working beneath the panels dropped by 4.46 degrees Celsius during working hours.