We tend to associate solar parks with dry and sunny environments like deserts. However, solar cells can also work well in areas with some humidity – like agricultural land. So, why not then combine agriculture with solar panels in the same area? Agrivoltaics is the approach to do just that, with studies now showing positive results.
Increasing our solar energy capacity will be a big part of solving the climate crisis. At the same time, global food demand is expected to increase by 50% by 2050. This can create a conflict of interest between food and solar energy production. Agrivoltaics suggests using the same area of land to produce food while rolling out more solar power.
The concept has been discussed for decades, but it’s only in recent years that it has become relevant to develop projects on a larger scale. Agrivoltaics technology can now be found in almost all regions of the world, from the US to South Korea. This has increased interest among researchers in better understanding the crop yield outcomes of using this approach.
Researchers at Cornell University have found growing commercial crops on solar farms can increase food production while improving solar panel performance and longevity. They created a tool to test the costs and benefits of placing solar panels on agricultural land and tested it on soybean crops, finding positive results that reinforce the role of agrivoltaics.
“There is potential for agrivoltaic systems to provide increased passive cooling through taller panel heights, more reflective ground cover and higher evapotranspiration rates compared to traditional solar farms,” senior author Max Zhang said in a statement. “We can generate renewable electricity and conserve farmland through agrivoltaic systems.”
Testing solar panels in agriculture
Using solar panel temperature data and a climate model, Zhang and his team evaluated solar panel height, the light reflectivity of the ground and rates of evapotranspiration (the process where water vapor rises from the plants and soil). They found solar panels set up over vegetation had a surprising cooling effect, enhancing the solar panel lifespan and agricultural productivity.
“As you decrease the solar panel operating temperature, you can increase efficiency and improve the longevity of your solar modules,” Henry Williams, lead author, said in a statement. “We’re showing dual benefits. On one hand, you have food production for farmers, and on the other hand, we’ve shown improved longevity and conversion efficiency.”
The researchers also make recommendations for placing the panels: panels should be placed higher above the soil. Solar modules mounted 13 feet (3.9 meters) above the ground resulted in temperature reductions of up to 50 F (10 C), compared to solar farms mounted just 1.6 feet over bare soil.
The study was published in the journal Applied Energy.