California energy officials are “cautiously optimistic” about maintaining grid reliability this summer, with the state benefiting from above-normal snowpack and precipitation coupled with expectations for cooler temperatures in coastal regions.  

That was the assessment of multiple presenters speaking during a summer reliability workshop hosted by the California Energy Commission on May 29. 

But climate change is making it increasingly hard to ensure reliable grid conditions, and planners must remain vigilant to avoid outages such as those in 2020, CEC Vice Chair Siva Gunda said during the workshop. “In 2020, we had two [rolling] outages on Aug. 14 and Aug. 15 — something we hadn’t seen at that point in 20 years — and it has been a primary focus in California to ensure electric reliability as we move forward.”  

Maintaining reliability requires a host of responses to keep up with decarbonization efforts and a warming climate, including having flexible and dispatchable resources, especially during the critical sunset hours when solar rolls off the system, said David Erne, CEC deputy director of resource planning, reliability and emergency response. But this summer is looking better than last, he said.  

Weather Patterns

Zeroing in on weather conditions, Amber Motley, director of short-term forecasting at CAISO, highlighted that the central Sierra Nevada had above-normal snow water equivalent this winter, although California was at 67% of its snowpack average as of May 20, said Jeff Fuentes, deputy chief of fire intelligence at Cal Fire.  

But the Pacific Northwest “did not have as good of a snow year,” Motley said, resulting in abnormally dry to moderate drought conditions in many portions of Oregon and Washington.   

This summer also should mark a transition away from El Niño, which is associated with warmer sea surface temperatures in the Pacific Ocean and hotter, dryer conditions in the northern U.S., to La Niña, marked by colder sea temperatures, drought and warmer conditions in the South and heavy rains in the Pacific Northwest.  

“For the Desert Southwest, this is really critical,” Motley said. “Because of the position of … where the heat is focused to be, it’s expected they don’t get as much monsoon moisture, which leads to less precipitation, but also leads to less cooling for them in the evening hours. The key piece as we head into summer is really watching the position of that [heat] ridge.” 

Another factor to watch, Motley said, is above-normal sea surface temperatures in the Atlantic, leading to forecasts that hurricane season will be more extreme — which impacts conditions in the West.  

“That’s going to be critical to watch because if you have big hurricanes, when we get into the August and July time period, they will move up into the gulf, and they kind of act like a traffic jam to the atmosphere. So, that could allow a ridge to stay parked over the West and not move for a number of days.”  

Taking all these pieces into account, forecasters anticipate above-average temperatures in the Desert Southwest, interior California and Rockies regions and a low probability of above-normal temperatures in California’s coastal regions.  

California fire risk is low to normal, Fuentes said, but “normal” typically means one to two large fires in each of the state’s service areas in June, three in July and six in August. Additionally, the Pacific Northwest will see normal risk of significant fires until July, when areas of Central and Southeast Oregon may shift to above-average potential for wildfire.  

Reliability

Changing weather patterns aren’t the only significant challenge to ensuring reliability. Expedited resource builds coupled with delays and resource retirements also are having an impact, said Branden Sudduth, WECC vice president of reliability planning and performance analysis.  

“Over the last two-year cycle when we developed our reports, we saw about 5,000 MW worth of generation retirements being delayed,” Sudduth said. “A lot of states in the West are focused on making sure they have adequate energy, adequate resources over the next couple of years. But we just want to make sure that people are alert and aware that those retirements are still going to happen in the future, and we just need to keep our foot on the gas pedal when it comes to making sure that we get new resources developed, built and online.”  

Sudduth provided an overview of NERC’s 2024 Summer Reliability Assessment, which evaluates June through September. This year’s assessment showed that while all areas of North America have adequate resources for normal summer demand, British Columbia, California, Mexico and the Southwestern U.S. have an elevated risk of insufficient operating reserves and loss of load under “extreme conditions,” defined as demand meeting or exceeding the 90th percentile threshold of the region’s demand curve. (See NERC Summer Assessment Sees Some Risk in Extreme Heat Waves.) 

The “good news,” Sudduth noted, is that no regions were identified as “high risk,” indicated as having insufficient operating reserves under expected conditions, for the upcoming summer.  

Focusing on the elevated risk identified for California and Mexico, the highest chance for load loss was the period ending at 7 p.m., though that totaled less than one hour. In the Southwest, the concern lay in the potential for a heat wave to increase the region’s probability of being unable to meet its operating reserve requirements.  

A broader reliability concern identified by WECC is the industry’s ability to keep up with the pace of development.  

“From January 2023 to June 2023, the Western Interconnection added around 14 GW of new generation capacity. Currently, we’re planned to add just over 17 GW” by summer, Sudduth said. “As we look at things such as supply chain delays and … we know there are workforce shortage issues, that’s really one of the challenges we face is can we build enough generation quick enough to meet our plans, and I assume that will continue to be one of our challenges in future years as the pace of generation builds [continues] to increase.” 

Christine Root, integrated resource planning and compliance supervisor at the California Public Utilities Commission, emphasized the rapid pace of resource development, with 18,500 MW of clean energy nameplate capacity coming online from 2020 to 2024, 5,700 MW of that last year — “the highest amount of clean energy on record for a given year thus far.”  

Ensuring reliability is dependent on long-term forward planning and procuring the volume of resources needed to support the evolving grid, Root added. The CPUC adopted a preferred system plan in February 2024, which estimates 55 GW coming online by 2035, 32 GW of which is expected to be solar.  

Though grid planners and forecasters presented a generally positive outlook for summer 2024, they continued to emphasize the importance of being cautious and vigilant.  

“Maintaining reliability is paramount and underscored by what we’re all collectively facing with the climate crisis,” said Christine Hironaka, senior adviser for energy for the office of Gov. Gavin Newsom.  

She noted that extreme heat events like the one in September 2022 are likely “to increase in frequency and intensity as time goes on.”  

“I think the good news is, last year … the grid did not have any major emergencies and I think the topline for me is we remain cautiously optimistic for this summer’s outlook,” she said.