Andrew Graham, THE PRESS DEMOCRAT
Over the last four months, two ponds at Healdsburg’s wastewater treatment plant were transformed by workers assembling rows of solar panels and pushing them out one by one to float gently on the water’s surface.
The project covered roughly half the combined 15 acres of ponds with 11,600 panels. It is likely the largest floating solar farm in the United States, the builders said, and will provide 8% of the city’s annual electrical needs.
The farm puts Healdsburg’s municipal power utility, itself a unique electricity model in the county, at the cutting edge of solar energy development. Floating solar farms are quickly gaining popularity in the U.S., backers say, particularly in places like Sonoma County where the price of land is dear.
“You couldn’t go out and buy a bunch of vineyard land for a solar project and make it economical,” Healdsburg utilities director Terry Crowley said. Floating solar farms are cost effective as the price of solar panels continues to drop, and are easy to build, Crowley said. Workers began assembling this one in mid-October and mostly finished by mid-January.
“It’s just new to California,” he said.
Windsor two years ago deployed a smaller floating solar installation to power its wastewater treatment plant. The new Healdsburg project is set to provide enough power to cover the annual supply of roughly 1,120 households.
The two-sided panels capture the sun’s energy as it strikes them from above, and also from below when sunlight reflects off the water. Metal cables anchor the floating farm to the ponds’ banks, while floating walkways give technicians and wastewater treatment plant workers the ability to check the panels.