When officials of Sayreville, New Jersey, decided to install a solar panel array to power a local water treatment, they couldn’t decide where to put it. Building a solar plant big enough to meet their electricity needs would require the town to clear some 15 acres of trees, which isn’t such a green option.
Taking inspiration from a novel solar project in California’s Napa Valley, officials in Sayreville elected to build a solar plant that floats upon a local lagoon. A glimmering blue grid of 12,000 solar panels blankets the lagoon, which draws water from the South River nearby. Over the next 15 years, the floating solar farm is expected to save the town $1 million in electricity costs.
While eastern Asia has been rather quick to adopt floating solar farms, the US has been slower, largely because the floating systems are still more expensive and less familiar than ground-mounted and rooftop solar projects. Still, they hold great potential. According to one estimate, there are 24,000 artificial lakes, ponds, and reservoirs that could host floating solar panels across the mainland United States. Combined, those projects hold the potential to produce enough solar power to equal almost 10 percent of the country’s annual electricity output.
Although it will take time for us to truly understand how floating solar farms affect water quality and natural habitats, early data from Sayreville says there are more benefits than just clean electricity and lowering utility bills. By shielding the lagoon’s surface, the raft could help limit harmful algae growth, reduce water evaporation, provide shade for fish, and keep water cool below. Cooler water temperatures might keep solar panels from overheating and operating less efficiently.
If researchers can quantify these advantages, it could help towns and developers justify paying more to put solar panels on water instead of on land.