For all their energy efficiency, solar panels can still be thirsty little buggers. In the desert, where dust picks up in the parched wind and settles on every surface, solar panels require a regular wash.
But instead of keeping solar panels in isolation, why not use all that excess water to grow something else beneath? A group of Stanford University researchers recommends using solar-panel drippings to cultivate agave, the same type of plant used to make tequila.
The researchers, led by post-doctoral candidate Sujith Ravi, say they’re hunting for synergy. In a recent paper published in Environmental Science and Technology, the Stanford group showed how a multi-tasking solar-agave operation might work.
“We tried to look at how much water is generated by these two types of land use and what happens when you can combine them,” Ravi explains. “The major issue is that many of the food crops don’t grow in deserts because of low water availability, and because the soil is not very fertile compared to other landscapes. But agave and aloe are adapted to desert landscapes.”
Agave can be used for biofuel, too. And according to the Stanford researchers, joining agave plants and solar panels in holy matrimony would result in even more energy generation per liter of water. Ravi imagines other benefits, too. For example, growing root systems between solar panels might help keep soil in place and prevent erosion.
But Ravi and his team aren’t the only ones to have thought of pairing solar with more traditional types of farming. The University of Massachusetts has a research farm partly dedicated to this kind of investigation. So does Fukushima’s “Renewable Energy Village,” which maintains rapeseed crops beneath a solar-panel installation.
The solar-agave co-location plan works out nicely in theory, but the researchers still need to test their idea in the field. Ravi, currently located in northern India, is seeking appropriate sites in desert-like areas.