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Surge of hydropower could force cutbacks of solar, wind

An abundance of rain and snowfall this winter has teed up what’s expected to be a bountiful year for hydroelectricity production in California, as reservoirs recover from five years of drought. But the projected rise in hydropower could force the state to sharply cut back on the amount of power produced from other sources, particularly renewable energy, according to the California Independent System Operator, the organization that manages most of the state’s vast energy system.  The system operator forecasts on some days it will have to block between 6,000 and 8,000 megawatts of electricity from the grid as a result of the profusion of hydropower. That’s the equivalent output of six to eight nuclear reactors.  In order to keep pace with the supply and demand of the state’s moment-to-moment energy needs, as one power sources rises, others have to be dialed down, in a process known as curtailment. Steven Greenlee, a spokesman for the system operator, said that California’s policies requiring increasing amounts of energy to be produced from renewable sources has boosted the amount of solar power.

 

“If the amount of excess supply we have on the grid is during the mid-morning and mid-afternoons, it’s likely that solar will be high on the list to curtail,” Greenlee said, adding that wind power production was likely to be curbed as well. Natural gas plants could also be affected. Hydroelectric output could also be curtailed, Greenlee said, but only when dams are beneath their “spill levels,” the safety threshold that determines when water must be released. The system operator must accept power from hydroelectric sources that are above their spill levels. That could happen as snowmelt pours into reservoirs. “Now we’re seeing a record amount of hydro plus a record amount of solar,” Greenlee said. “And so that’s shaping up to be a potential for more excess on the grid than what we’ve ever encountered before.” Fitch Ratings released a memo in March predicting that curtailment brought on by overproduction would hurt renewable energy producers.  Matthew Reilly, director of U.S. public finance for Fitch, expects large, utility-scale solar projects to suffer the most should the curtailment projects become reality. Those projects are largely in Southern California. Much of the energy generated from rooftop solar panels doesn’t feed back directly into the power grid, so homeowners are likely to be unaffected, Reilly said.  The system operator pays some energy providers to power down when it’s necessary to cut back, but Reilly said that “most renewable projects don’t receive revenue when they’re being curtailed, so they would lose out on revenue they would otherwise get.”

Thank you, Ron