A fast-growing, massive wildfire in southwest Oregon disrupted exports of electricity from the Northwest July 9-14 as California sweated through another heat wave, forcing the state's grid operator to call for voluntary power conservation and to edge toward invoking rolling blackouts.
As of July 16, the Bootleg Fire had grown to 241,497 acres and was only 7 percent contained, the National Interagency Fire Center reported, and accounted for more than 75 percent of the acreage burned in Oregon. The blaze started July 6 in Klamath County.
The disrupted 500 kV lines that comprise the AC Intertie north of the Oregon-California border normally carry 4,800 MW. The lines are owned by BPA, PacifiCorp and Portland General Electric.
However, BPA, the operator of the lines, reduced the feed to a single line carrying 428 MW to assure grid stability after smoke particles from the fire acting as airborne conductors caused all three of the lines to trip in and out of service July 9, Bonneville spokeswoman Maryam Habibi told California Energy Markets.
Adding to the problems, the Oregon-California path that feeds into Southern California, the Pacific DC Intertie, was also derated, to about 1,500 MW from a maximum of 3,200 MW for reliability issues.
"Operationally, if we lose the DC Intertie . . . its capacity would automatically switch to the AC Intertie, which would cause a stability problem if it doesn't have enough capacity, so we derated the DC line to protect the system as a whole," Habibi said.
All told, at times during the five-day period, California couldn't access about 5,500 MW from the Northwest.
To help fill the power gap, Gov. Gavin Newsom's office issued an emergency proclamation on July 9 suspending air pollution and generation limits on fossil-fueled power plants and portable generators.
The California Independent System Operator triggered a Flex Alert the same day to help reduce load, asking consumers to conserve power, and extended it through July 10. A separate Flex Alert was issued July 12 to address ongoing extreme heat and high demand.
In a July 10 press conference, CAISO CEO and President Elliot Mainzer said the grid was in a "very stressed condition."
He added that the ISO is "simply not going to rely" on the AC Intertie during the extreme conditions, and stressed the importance of reducing load.
CAISO COO Mark Rothleder affirmed in the press conference that the grid's high stress levels were directly due to the intertie's status. He also noted that CAISO might not be able to maintain its required 3,000 MW of operating reserves, leading to concerns about having sufficient capacity to meet those margins.
However, the grid operator managed to avert rolling blackouts largely through conservation by the time the AC Intertie returned to service.
BPA and PacifiCorp lines returned to service around 2 p.m. July 13, and the PGE line followed suit July 14 around 4:30 p.m. PGE spokeswoman Andrea Platt said the company's line was returned to service when fire concerns allowed. She noted that the utility was able to serve its customers using Northwest resources.
The Bootleg Fire is the biggest of nearly 70 large active fires burning mostly in Western states. The acreage burned by Oregon's 10 fires represents 30 percent of the total from the 70 fires.
Bonneville's Habibi noted that several of the 10 fires are near other BPA facilities, and will require constant monitoring.
She said that the agency had to take lines out of service due to the Darlene Fire near La Pine, Ore., which was 5 percent contained as of July 15.