California’s Shift From Natural Gas to Solar Is Playing a Role in Rolling Blackouts.
California was beset by its first rolling blackouts since the 2001 energy crisis, as a heatwave slammed the Western U.S. Friday and Saturday. Electricity demand for air conditioning throughout the region stretched California’s power capacity and limited the state’s ability to import power from nearby states.
But the blackouts were also a side effect of the state’s increasing shift to solar power and away from natural-gas-fired generators, according to state grid operator CAISO and Wood Mackenzie analysts. This shift pushed back the moment of “net peak” demand on the state’s grid — a measure of total demand minus renewable energy’s contribution — into later in the evening, leaving CAISO with less dispatchable generation to fill in shortfalls between supply and demand.
With high heat and peak electricity demand expected to continue throughout the week, California may be forced to rely on rolling blackouts for the immediate future, CAISO President Stephen Berberich said in a Monday meeting. Gov. Gavin Newsom declared a state of emergency on Monday allowing backup generators, including those deployed to customers facing wildfire prevention blackouts, to be used to combat outages, and demanded an investigation into the causes of the grid shortages.
But without changes to how the state manages its grid capacity needs, the same shortfalls could plague the state for years to come, Berberich said, in a scathing attack on what he called California policymakers’ failure to prepare for this eventuality. “The situation we are in could have been avoided,” he said in Monday’s meeting. CAISO has told regulators for years that “there is inadequate power available during the net peak, the hours when the solar [generation] has left the system.”
Friday and Saturday’s rolling blackouts, or “Stage 3 Electrical Emergencies” in CAISO parlance, forced utilities to cut off power to hundreds of thousands of customers between the hours of 6 p.m. and 8 p.m. Those are the hours when solar generation drops to zero, leaving CAISO with a “net peak” that comes one to two hours after its peak demand hour on the system.
Why more solar can’t help solve California’s “net peak” problem
CAISO’s peak demand levels over the weekend were lower than its historical highest peaks in 2006 and 2017. But “the operational challenge that we face now is more around that net peak event,” Berberich said, which includes accounting for increasing demand from rooftop solar-equipped customers as their own self-supplied solar power dissipates. “That solar resource is fading fast, and we have to ramp up other resources quickly to meet that net peak event.”
California has also lost a good deal of the generation capacity that it had in years past, Berberich noted. “In 2006, we had a lot more capacity on the system,” including the now-closed San Onofre nuclear power plant and thousands of megawatts of natural-gas plants that have since closed. California is set to close even more gas-fired power plants in the coming years, including several coastal plants targeted for retirement to reduce their harmful effects on marine ecosystems.
Wade Schauer, Americas research director at Wood Mackenzie Power & Renewables, noted that California has shut down about 5 gigawatts of dispatchable generation since 2018, while it has only added about 2,200 megawatts of “non-intermittent” generation since then.
California “just hasn’t done enough to keep resource adequacy where it should be, and the reserve margins have gotten tighter more quickly,” Schauer said. The chart below from WoodMac indicates how California’s total generation capacity has fallen below both gross peak and net peak needs, leaving a gap that must be made up from imports from other states.