Five stories up at Colorado State University, a highly improbable garden grows beneath a long row of rooftop solar panels. It’s late October at 9 a.m., when the temperature hits 30 degrees Fahrenheit and the wind is blowing. Shortly before my arrival, researchers had removed the last of the frost-intolerant crops from the substrate beneath the panels, a total of 600 pounds for the season. In their place, cool-season foods like leafy greens – arugula, lettuce, kale, Swiss chard – still grow, sheltered from the intense sun here.
This is no ordinary green roof, but a vast outdoor laboratory full of sensors, supervised by horticulturist Jennifer Bousselot. The idea behind agrivoltaics on roofs is to imitate a forest on top of a building. Just as the shade of towering trees protects undergrowth from solar stress, solar panels can also encourage plant growth – the overall goal being to produce more food for growing urban populations, while saving land. water, by generating clean energy, And make buildings more energy efficient.
“When you think about what we will need as a society – our building blocks – it will be food, energy and water, as has always been the case,” says Bousselot. With rooftop agrivoltaics, “you can produce, especially in a mostly unused space, two of these things and keep the third.”