What else can solar panels do?

We’ve all seen arrays of solar panels on rooftops. They convert the sun’s energy into electricity, lowering the homeowner’s electric bill—and maybe even adding power to the grid. On a larger scale, utilities install massive solar arrays as part of their decarbonization strategy.

But as we install more solar arrays, it’s worth thinking about how to make the most of them. That is, how can we make solar panels work more efficiently? And what else can we get them to do for us?

Throwing shade

Swimming pools and green lawns notwithstanding, California is a desert, and demand for its scarce water increases as the population grows. Meanwhile, climate change has brought hotter, drier summers.

The apparent ease of California life is an illusion, and those who believe the illusion real live here in only the most temporary way. I know as well as the next person that there is considerable transcendent value in a river running wild and undammed, a river running free over granite, but I have also lived beneath such a river when it was running in flood, and gone without showers when it was running dry.—Joan Didion

California’s 6000 km (3700 miles) of aqueducts supply water to the cities and fields. In transporting the water, they lose a great deal of it to evaporation. Scientists at the University of California propose to float solar panels on reservoirs and irrigation canals. This has the dual benefit of reducing evaporation and cooling the solar panels so they work more efficiently.

Covering the canals with solar panels would prevent evaporation of roughly 40,000 cubic metres of water—16 Olympic swimming pools’ worth—from each kilometre of canal every year.—Nature Sustainability

Moving all that water takes a lot of electricity to power the pumps. Indeed, California’s water conveyance system is its largest consumer of electric power. Solar panels could make the system largely self-powering.

It is easy to forget that the only natural force over which we have any control out here is water, and that only recently. In my memory California summers were characterized by the coughing in the pipes that meant the well was dry, and California winters by all-night watches on the rivers about to crest, by sandbagging, by dynamite on the levees and flooding on the first floor.—Joan Didion

Beneficial habitat

sheep grazing under solar panels
Ovine multitasking: Sheep grazing under solar panels manage the vegetation, reducing the danger of fires and encouraging new growth. Shutterstock image.

You might think that generating electricity from a solar farm would be a good use of land. But what if you could make the solar panels more efficient while also providing a habitat for pollinators? That’s the idea behind a suite of Minnesota statutes that regulate solar installations.

An owner of a ground-mounted solar site with a generating capacity of more than 40 kilowatts may follow site management practices that (1) provide native perennial vegetation and foraging habitat beneficial to game birds, songbirds, and pollinators, and (2) reduce storm water runoff and erosion at the solar generation site.—Minnesota Statute 216B.1642

For example, a Chisago County solar farm owned by Enel Green Power uses an assortment of native plants to provide a habitat for bees and other pollinators. The vegetation makes for a cooler environment for the solar panels, so they operate more efficiently. The perennials’ long roots improve the soil. To manage the plants, a herd of sheep grazes on the land, controlling dead material and stimulating new growth to reduce the danger of fires. A miniature donkey comes in occasionally to protect the sheep from coyotes.

Video: “Sheep may safely graze” by J.S. Bach, extols the benefits of good government. It does not mention pollinators or donkeys.