Could the California Aqueduct Turn Into a Solar Farm?By TODD WOODY
In Wednesday’s Times, I wrote about start-up companies developing solar panel arrays that float on water. The companies see a potentially large market to generate electricity from building floating arrays for irrigation and mining ponds, hydroelectric reservoirs and canals.
But the great white whale for some of these solar developers is deploying floating photovoltaic arrays on the California Aqueduct, the 400-mile long canal that irrigates much of the state’s agricultural heartland and delivers water to Southern California.
“It’s a dream for us,” said Phil Alwitt, project development manager for SPG Solar, a Novato, Calif., company that has built floating solar arrays for winery irrigation ponds.
The idea is to reduce evaporation while producing electricity to offset the power consumed by the massive pumps that move water through the aqueduct. Solaris Synergy, an Israeli company, estimates that its floating solar system could generate two megawatts per mile of the aqueduct.
“You could generate gigawatts from all that unused space on the California Aqueduct and there’s a huge electricity demand,” said Danny Kennedy, co-founder of Sungevity, an Oakland, Calif., solar installer.
Mr. Kennedy, a Greenpeace activist turned entrepreneur, said his original business model a decade ago was to put a lid of solar panels over aqueducts. But he and his colleagues soon abandoned that idea because of the high cost of photovoltaics at the time.
Solar-panel prices have plummeted in recent years, and companies like SPG Solar say their floating systems are cost-competitive with ground-mounted arrays.
But Ralph Torres, deputy director of the State Water Project, politely threw cold water on the prospect that the California Aqueduct would go solar anytime soon.
“One of the issues with the aqueduct is that a lot of people talk about the benefit to evaporation,” said Mr. Torres, who noted he had talked to a number of companies over the years about putting solar panels on the canal. “The reality is that there’s an insignificant loss of water from evaporation on the aqueduct.”
And floating solar panels would prove an obstacle to performing routine maintenance on the aqueduct as well as responding to leaks and other emergencies, according to Mr. Torres.
Finally, the State Water Project’s electricity demand far outstrips any power likely to be generated by floating solar farms, he said.
One pumping station alone features more than a dozen 80,000-horsepower motors. “Our pumping loads are orders of magnitude greater than what you could generate with even good-sized solar,” said Mr. Torres.
That doesn’t mean the State Water Project is opposed to solar energy. In fact, he said, the agency is investigating building its own solar arrays — on land.