Eclipse to interfere with solar collection
SACRAMENTO — When Monday’s eagerly awaited eclipse arrives, local utility districts will have electricity reserves ready to fill any gaps in power resulting from a drop in solar energy, the utility assured residents Tuesday.
In the Lodi area, as much as 76 percent of the the sun could be obscured when the moon passes in front of it on Monday, according to astronomers. For the electric service, that means a lot less solar power can be generated when the eclipse takes place from 9 to 11:30 a.m.
“The California independent system operator that operates the regional transmission grid has been planning for this for a long time,” said Adam Brucker, the City of Lodi’s business development manager.
While the solar eclipse will affect solar energy generation statewide, the grid operators will simply pull more power from other sources, such as natural gas, hydroelectric and geothermal plants.
However, some Lodi customers generate their own power from solar arrays on their rooftops. They’ll be affected, Brucker said, but since they’re still connected to Lodi’s power grid, they’ll still have electricity.
“It’s going to have a minimal effect just because of the time of day,” he said.
The Sacramento Municipal Utility District likely won’t have to draw on the energy reserves, said SMUD spokesman Christopher Capra.
The timing of the natural phenomenon is fortuitous for SMUD because power use tends to be lower in the morning, he said. But the company is being extra cautious to ensure it will meet demand during a season when air conditioning use already pushes electricity demand to its peak.
“There is a considerable amount of solar on the grid in California and elsewhere, so it’s our responsibility to look at that situation and determine if any measures should be taken,” Capra said.
Solar power comprises nearly 300 megawatts of the power on SMUD’s grid, or slightly less than 10 percent of the over 3,000 megawatts the agency supplies when demand is at its highest. The agency’s solar energy is divided about evenly between power generated by homes and businesses and electricity from power plants.
Capra said SMUD already has arrangements to buy extra power from generators throughout the western U.S. on hot days when electricity use is expected to run high; the utility’s eclipse preparations involve similar purchases.
Utility agencies all around California will be affected by the eclipse, albeit to slightly varying degrees because different locations will see different amounts of the sun blocked.
In May, the state’s Public Utilities Commission urged customers to turn off or unplug their appliances as one measure to save energy during Monday’s expected dip in sunlight.
Steven Greenlee, a spokesman for the California Independent System Operator, which runs the state’s power grid, said his organization started planning for the eclipse a year in advance, even reaching out to agencies in Europe that have experience preparing for eclipses. European groups recalled not having enough backup power ready, Greenlee said.
With lots of hydroelectric energy from a rainy winter as well as ample natural gas power, however, Greenlee doesn’t foresee any issues meeting electricity demand in California. SMUD is similarly well-positioned, Capra said.
“We have considerable hydropower, considerable thermal power, as well as wind power, so we’re looking really good for the 21st and the summer,” Capra said.