More Power for the Carrot Capital

An Australian company is setting up an unusual solar array in the agricultural city of Holtville, CA—known variously as the Winter Salad Bowl and the Carrot Capital of the World—that combines water savings with renewable energy. The company Infratech has devised a floating solar panel array that will sit on the surface of the city’s water-supply ponds. [text_ad] City officials point out several advantages to covering the ponds with solar panels. First, it will reduce evaporation, which has become more important than ever during the ongoing drought. Second, it will block sunlight from reaching the water, keeping it cooler and checking the photosynthesis process that causes blue-green algae to form, so the water will require less chlorine treatment. Third—because Holtville is in an earthquake-prone region—the panels won’t topple during an earthquake (the system is designed to withstand waves). And finally, no valuable agricultural land will be lost to the array. To stop evaporation, the Los Angeles Reservoir tried a different sort of cover last year by releasing 96 million 4-inch plastic balls into the water. They cover 175 acres of the reservoir’s surface and should prevent 300 million gallons each year from evaporating. Infratech has previously installed one other floating solar array system, in the Australian city of Jamestown. As the California system will do, Jamestown’s array is powering the local water treatment plant. It is also feeding energy back into the grid. You can find more details in this article. In total, Holtville’s 1-MW system will contain more than 3,500 solar panels. California has a goal of 50% renewable energy by 2030. It’s been suggested, in Stormwater magazine and elsewhere, that we should be designing more of our stormwater management infrastructure to enhance water supply—in other words, to capture, store, and use runoff rather than letting it go. If floating solar arrays prove feasible and catch on in the US, do you see possibilities for something similar in stormwater facilities, even on a small scale?