'Homer Simpson Move’ by PG&E Was ‘Final Tipping Point’ Into California's Second Evening of Rolling Blackouts Last Summer

At 6:13 p.m. on Saturday, Aug. 15, 2020, a gas-fired power plant in the Central Valley city of Firebaugh suddenly ramped down production. The move was the exact opposite of what California's Independent System Operator wanted the Panoche Energy Center power plant to do at that moment.

CAISO, which manages most of the state's electric grid, was already struggling to find enough power to meet demand during a regional heat wave. It hoped to avoid a repeat of the previous day, when it had called for rolling blackouts — California's first in nearly two decades. But the loss of about 250 megawatts at Panoche would ultimately prompt the agency to call for more rolling blackouts that evening.

CAISO later reported that it understood the ramp down "to be due to an erroneous dispatch" from the plant's scheduling coordinator. Every power plant has a scheduling coordinator, acting as the point of contact between CAISO and the plant, relaying and confirming the grid operator's instructions on whether the plant should ramp production up or down.

To date, two details have been left out of CAISO’s public account of what happened at the Panoche plant that day:

1. The incident was the “final tipping point” before CAISO began the process of initiating a second day of rolling blackouts.

2. The scheduling coordinator who delivered the erroneous dispatch was PG&E.

Since last year’s rolling blackouts, which left hundreds of thousands of Californians without power for parts of two consecutive evenings, CAISO has produced two root-cause analysis reports issued jointly with California's Public Utilities Commission and Energy Commission — one in October and another in January. Both reports run more than a 100 pages, and conclude that the Aug. 15 rolling blackouts "were not caused by any single generator or resource type."

While the reports mostly place blame on climate change and poor planning, the context regarding the incident at Panoche, which is operated by a private investment firm, remains murky.

"It is not at all clear why a modest 248-megawatt reduction in output from Panoche would have precipitated rolling blackouts 15 minutes later," said Bill Powers, a San Diego-based energy consultant.

"It was such a Homer Simpson move to back off on power at a time when the grid needed that power," he added. He said it speaks to larger issues about CAISO's clarity on other major factors, including the fact that California was exporting power during the rolling blackouts.

Last year, in response to media inquiries from the San Francisco Chronicle and KQED, PG&E confirmed it had made the erroneous dispatch, and said it immediately corrected the problem after identifying it. The outage at Panoche lasted less than 30 minutes, according to PG&E, which said the drop represented roughly 0.5% of CAISO's total load of 44,913 megawatts at the time.

In an email this month, PG&E spokesperson James Noonan wrote: "Importantly, this incident was not cited as a contributing factor in the joint agencies' final root cause analysis."

But that contradicts what CAISO recently told KQED. "The ramp down at Panoche was clearly cited in the root cause analysis as a contributing cause of the rotating outages," CAISO spokesperson Anne Gonzales said in an email last week.

And in an email from last October, Gonzales called the loss of the nearly 250 megawatts at Panoche "a final tipping point leading to resource deficiency."

No version of that phrase appears in the public reports prepared for Gov. Gavin Newsom — including the most recent one issued in January. Gonzales said that information was omitted "because it isn’t germane to the root causes of the outage."

As to why PG&E’s role is left out of CAISO's public record, Gonzales said, "We didn’t name the scheduling coordinator because the CAISO’s event analysis is focused on the operational issues, and the name of the scheduling coordinator is irrelevant to that analysis." CAISO, she continued, has "to consider whether certain information is confidential or commercially sensitive."

If CAISO did clearly cite the incident at Panoche as a contributing factor to the Aug. 15 blackouts, as they claim to have done, the point has been lost on many state lawmakers.

KQED surveyed a half-dozen Democratic and Republican members of the state Assembly Utilities and Energy Committee. Nearly all said they were unaware that the Panoche incident was the “final tipping point” into resource deficiency, or that PG&E played any role at Panoche.

"It’s perplexing," said Assemblymember Jim Patterson, R-Fresno, vice chair of the committee. "There’s a lot of ambiguity about exactly what happened. Communication should have been crystal clear with the gas plants that can fire up and provide reliable base load. If that was the tipping point, we are too easily tipped over."

"When we see the failure of our system resulting in massive blackouts like we did last summer, the public deserves full, clear and transparent answers as to why the system failed," said Assemblymember Rebecca Bauer-Kahan, D-San Ramon, who joined the committee this year. "Anything less is unacceptable."

The office of Assemblymember Chris Holden, D-Pasadena, who chairs the energy committee, issued a statement to KQED echoing CAISO’s stance, but did not respond to questions about whether CAISO and state regulatory agencies should have told lawmakers that PG&E is the plant's scheduling coordinator.

The mishap has also prompted some energy experts to note that allowing PG&E to serve as a scheduling coordinator is like letting the same party be both broker and accountant in a financial transaction.

CAISO recently denied KQED’s second request for unedited sound recordings of verbal communications that occurred between CAISO and the PG&E scheduling coordinator at Panoche on the evening of Aug. 15. John Spomer, CAISO's senior counsel, noted that the grid operator is not subject to the Public Records Act. CAISO is a corporation, not a public agency, and audio recordings of dispatches are considered confidential under that policy, he said.

Severin Borenstein, a professor of energy policy at UC Berkeley's Haas School of Business, likened blaming the second day of rolling blackouts on Panoche to faulting the loss of a baseball game on the last batter who loses the game. But he acknowledged that CAISO, on whose governing board he sits, may need to address quality controls to prevent what happened at Panoche, including reexamining the way dispatches are communicated.

"It speaks to the fact that it's 2021," Borenstein said. "Are we doing communication and cross-checking in a modern way?"