Climate

California Will Soon Be Home To The Country’s Largest Floating Solar Array

CREDIT: AP Photo/Eric Risberg

Winemaker Greg Allen, right, takes a boat out with Dimas Duran from SPG Solar to inspect floating solar panels on a pond at the Far Niente winery in Oakville, Calif., Tuesday, Sept. 18, 2007.

For one California electricity provider, investing in regular solar arrays that are installed on the ground or a roof isn’t enough — the company, instead, is setting its sights on solar that floats.

Sonoma Clean Power in California’s wine country has announced that it will be building the largest floating solar array in the U.S., a project that’s scheduled to be completed in 2016 and will create enough energy to power 3,000 houses. The array will span six wastewater ponds filled with treated sewage.

That location was strategic for vineyard-rich Sonoma County, said Cordel Stillman, deputy chief engineer at the county’s Water Agency, which oversees the wastewater ponds.

“We know it’s hard to get big solar projects in Sonoma County. You get pushbacks on aesthetics and the taking of agricultural land,” Stillman told the Press Democrat. “We took a look and said ‘Where else can we put solar?’”

The solar arrays are another source of revenue for the Sonoma County Water Agency. Pristine Sun, the developer in charge of the project, is leasing the ponds from the agency for $30,000 a year.

“We consider these bodies of water an ‘underutilized asset’ or ‘un-utilized asset’ [from which] their owners can now enjoy a modest revenue stream by leasing the water surface rights to Pristine Sun, in order for us to sell clean energy to the local utilities,” Pristine Sun CEO Troy Helming told Greentech Media.

Floating solar — which typically involves installing solar panels on pontoons that rest on the surface of a body of water and is also called “floatovoltaics” — has been installed in California before. Far Niente, a Napa Valley wine producer, has a 1,000-panel floating solar installation on its winery’s irrigation pond. The array, coupled with 1,300 solar panels on the land next to the pond, provides enough yearly energy to offset the winery’s power usage. As the New York Times reported in 2011, the solar arrays are useful in other ways too: they can help prevent harmful algae growth and prevent evaporation from ponds.

Floating solar has already caught on in other parts of the world. Australia is starting construction on its first floating solar power plant this year, which will feature a solar array on a wastewater pond. France, too, is home to a large-scale floating solar array, and Japan has also begun taking floating solar seriously. Japan’s lack of space and desire to move away from nuclear power after the Fukushima disaster make it a prime spot for floating solar. It’s unsurprising, then, that the country is home to the world’s largest floating solar array.

Wind has also emerged as an energy source that can be housed not only on the ocean’s floor but also floating atop its surface. Floating turbines are helpful in deepwater locations where installing seafloor wind turbines isn’t feasible. Last year, a Seattle wind company gained approval to start developing plans for a 30-megawatt offshore floating wind farm, which would be the one of the first of its kind in the U.S. And in late 2013, a Norwegian oil company announced that it had plans to build a 30-megawatt floating wind farm off the coast of Scotland.