California Braces for New Reliability Crisis as Wildfire Threatens Crucial Intertie

The rapidly spreading Bootleg Fire tripped off transmission lines that transport power from the Pacific Northwest to California and other states over the weekend, prompting the California Independent System Operator (ISO) to issue another Flex Alert—the sixth such conservation notification this summer.

According to the state’s Incident Information System, the intense fire in Southern-Central Oregon continues to ravage the Fremont-Winema National Forest, which is about 11 miles northeast of the town of Sprague River. Since its origin on July 6, the fire has expanded to 150,812 acres, driven by hot, dry, windy weather. Conditions escalated in the afternoon on Sunday, resulting in immediate, life-threatening risk to public and emergency responder safety. “Conditions were so extreme that firefighters needed to disengage and move to predetermined safety zones. Fire managers evaluated conditions and looked for opportunities to reengage firefighters safely,” the state reported.

The fire exacerbates delivery of much-needed power supplies in the face of what is expected to be soaring power demand. It comes as another dangerous, record-setting heatwave settles over much of the West. Heat advisories have been issued in various cities stretching from Washington’s Columbia Basin and Yakima Valley all the way to California’s Mojave Desert—where temperatures are already soaring well-above 120F—and as far east as Utah’s Great Salt Lake Desert.

California-Oregon Intertie Under Threat

CAISO CEO Elliot Mainzer and Senior Vice President and Chief Operating Officer Mark Rothleder on Saturday told reporters that the fire had threatened the California-Oregon Intertie, an alternating current (AC) connection that constitutes the first point of connection between southern Oregon and northern California.

“Because of the fire, which has nearly doubled in size in each of the past two days, three of the lines feeding into the intertie in Oregon were tripped and went out of service,” said Mainzer. But the fire is also threatening an associated direct current (DC) intertie, the Pacific DC intertie, which feeds into southern California from central Oregon, he said. While the Pacific DC intertie is not directly affected by the fire, its power-carrying capability has been decreased owing to a contingency-related interplay of the lines that are affected by the fire. “Collectively, between these two lines, California has lost about 5,500 MW of power, and that is a significant fraction of the state’s power supply,” he said.

The lines came back into service briefly before tripping again on Saturday, putting CAISO on guard to shore up replacement power during the extreme conditions, Rothleder said. However, Rothleder noted other Western entities had been similarly stricken. Nevada’s NV Energy on Sunday also urged conservation measures to offset “energy supply issues caused by record-breaking heat and wildfires affecting electric transmission lines throughout the western U.S.” The Turlock Irrigation District, which serves California’s Central Valley, also warned of “extremely high” energy loads.

 In a press release on Sunday, CAISO said that because the lines were “still unreliable,” power supplies to its service territory had been reduced “by as much as 3,500 MW.” It reiterated concerns that the Bootleg fire posed new, “extraordinary conditions” for the power-strapped grid. 

Stricken by repeated extreme heat events, the prospect of worsening drought, incremental resource delays, and the “unforeseen” loss of 300 MW in thermal resources, California earlier this month set out to secure additional energy resources to ensure reliability this summer. On Saturday, Mainzer lamented climate change’s impact on the grid.

“I think many of us are really recognizing now that the climate change and these extreme heatwaves happening in the earlier parts of the summer now forced all of us to do things that we really never imagined just a few years ago,” he said. “But we’ve entered this new normal. And now it’s really going to take all of us doing our own part during this important clean energy transition to keep the lights on.”

Shoring up Supply, Pleading for Conservation

Along with a fresh Flex Alert, which urges consumers to conserve power between 4 p.m. and 9 p.m. on Monday, the grid operator restricted maintenance operations at power plants for July 12, requiring power generators in its region to postpone any planned outages.

Meanwhile, California Gov. Gavin Newsom on July 10 signed an executive order to allow the emergency use of auxiliary ship engines berthed in California ports to relieve pressure on the electric grid. The governor on July 9 also signed an emergency proclamation that suspended permitting requirements to enable the use of backup power generation. These include restrictions on air quality and fuel limits that prevent facilities from generating additional power during peak demand hours, from 3 p.m. to 10 p.m.

Over the weekend, the North American Electric Reliability Corp. (NERC) reportedly also issued a high-level energy emergency alert for the region, though Mainzer said from an ISO perspective, the grid was at a “stage 2,” which meant it did not move into load shed. “We are in the process of transitioning away from a separate alert and warning system that we’ve been using it the ISO for a number of years and more toward the standard definitions,” he explained. “But we’re still, at this point in the transition, using our own definitions. Over the course of the coming months, we’ll be better harmonizing those things to avoid any confusion on that front.”

—Sonal Patel is a POWER senior associate editor (@sonalcpatel, @POWERmagazine).