Author: Emma Bryce
It’s an ironic fact that sun-harvesting solar panels function better when they’re not too hot. But luckily researchers have now discovered precisely how to cool them down. Building solar panels at a specific height above crops can reduce surface temperatures by up to 10 °C, compared to traditional panels constructed over bare ground, they’ve found.
The results, published in the journal Applied Energy, are the latest contribution to a growing body of research on agrivoltaics: a farming method that aims to maximize land use by pairing solar panels with cropland, thus minimizing competition between energy production and food. We already know that agrivoltaics can increase land-use efficiency, produce plenty of electricity on minimal land, and may also improve crop yields by shielding plants from heat and wind.
But how to maximize this relationship for the hard-working solar panels is something that we knew less about—until this research.
Hovering solar panels over an area vegetated with soybeans would reduce panel temperatures by 10 °C compared to traditional solar farms built over bare ground. Mainly, this was due to the light-reflecting powers of the soybeans (70%, versus just 20% from bare ground), which cooled the ground surface and by default reduced the panels’ exposure to heat. But the exact panel height was important too: the model revealed that constructing solar panels on legs that stood 4 meters above the crops created the optimal conditions for convective cooling to occur between the ground and the units. Evapotranspiring vegetation also provided cooling as water droplets formed at the base of the panels.