Five stories off the ground at Colorado State University, a highly unlikely garden grows under a long row of rooftop solar panels. It’s late October at 9 am, when the temperature is 30 degrees Fahrenheit and the wind is cutting. Not long before my arrival, researchers had pulled the last frost-intolerant crops out of the substrate underneath the panels, a total of 600 pounds for the season.
That is, you don’t need to run air-conditioning as much to properly cool the place during a heat wave. That’s an especially welcome benefit given the urban heat island effect, in which city temperatures can soar far above surrounding rural areas, which have lots of greenery to sweat and cool the air. With rooftop agrivoltaics, you’re essentially bringing the country into the city, a strategy known as rurbanization.