California grid at stage 2 emergency as heat wave, Mosquito Fire add to power woes

California was again facing a significant risk of rolling blackouts Thursday, with the task of keeping the lights on through a record heat wave complicated by the Mosquito Fire burning in Placer County.

The Independent System Operator, which manages the state’s power grid, called a stage 2 “energy emergency alert” for 4 p.m., which would allow power production from backup generators and other facilities that normally are prohibited by air pollution regulations.

The ISO also declared a Flex Alert, asking for conservation as electricity demand was initially expected to peak at around 51,300 megawatts — the second highest on record, trailing on Tuesday’s consumption.

However, by late afternoon demand came in lower than forecast, topping out at just under 49,000 megawatts.

The heat wave was expected to ease slightly Friday, with more normal temperatures forecast for the weekend. But ISO officials warned that Thursday’s weather, with temperatures at or near 110 degrees in parts of the Sacramento Valley, created a major obstacle to getting through the heat wave without any rolling blackouts.

“We think we’re close to turning the corner but we certainly have challenges this evening,” said Elliot Mainzer, chief executive of the ISO. If rolling blackouts occur, they would be the first since August 2020.

SMUD isn’t part of the ISO system but wasn’t exempt from pressures on energy supplies. The Sacramento Municipal Utility District called on its customers once again to conserve energy Thursday afternoon and evening, urging them to turn thermostats to 82 degrees from 4 to 9 p.m. The utility also asked commercial and industrial firms to turn off unnecessary lighting and take other steps to reduce demand.

“SMUD will exhaust every avenue before rotating outages are called,” the utility said.

On the statewide level, Mainzer said conditions could turn dicey after a near-miss on blackouts Tuesday and a “relatively quiet operation” Wednesday.

For the ninth straight day, the ISO declared a Flex Alert from 3 to 10 p.m., a plea to turn thermostats to 78 degrees and defer using heavy appliances.

The seven-hour alert was two hours longer than usual, reflecting some uncertainties about the availability of solar and wind energy.

How Mosquito Fire smoke could impact blackouts

The Mosquito Fire, which prompted the evacuation of Foresthill and its population of 1,500, was the reason behind the concerns about solar power. As the fire grew to 6,870 acres, smoke was beginning to waft over the Sacramento region Wednesday morning.

The exact implications for power outages were unclear. If the smoke mainly blanketed urban areas, it would help reduce temperatures and tamp down the demand for electricity, said Mark Rothleder, the chief operating officer at ISO. But if it created major cloud cover over the industrial-sized solar farms that dot rural areas, it could depress solar energy supplies that have become such a major part of California’s power portfolio.

“We’ve seen both effects,” Rothleder said.

Another potential problem: Hydro power supplies, already depleted by drought, were in danger from the fire. Cal Fire said several hydro facilities in Placer County were threatened, including the Ralston plant east of Foresthill. All told, about 200 megawatts of hydro power was in jeopardy of going offline, Rothleder said.

It wouldn’t be the first time during this heat wave that wildfire was jeopardizing grid stability. A major fire near Castaic, outside Los Angeles, damaged transmission lines and temporarily knocked 700 megawatts of power offline last week.

This story was originally published September 8, 2022 at 12:22 PM with the headline "California grid at stage 2 emergency as heat wave, Mosquito Fire add to power woes."