Event with SDG&E stresses conservation and storage for grid reliability

By ISO Staff |

Conservation and energy storage were the focus in San Diego this week when the ISO’s Elliot Mainzer and Caroline Winn, San Diego Gas and Electric’s chief executive officer, joined forces to highlight what’s needed to maintain electricity reliability as California continues its transition to a decarbonized grid.

Mainzer, president and chief executive officer of the ISO, was in San Diego on Wednesday, July 7 to tour the utility’s newest battery storage installation. Named Top Gun after the famed naval pilot training program once located nearby, the 30 Megawatt lithium-ion battery facility came online at the end of June.

The facility is part of SDG&E’s push to add storage as California moves to a power system that doesn’t produce greenhouse gases but can also meet the demand for electricity late in the day when solar energy is unavailable.

“This battery storage resource is the perfect example of the kind of clean capacity that California is going to be putting into its system increasingly in the years to come, Mainzer said.

Because California is still in the early stages of that clean-energy transition, Mainzer said, consumers and industry will continue being asked to conserve when extreme heat strains the system and until we have the right mix of renewable and storage resources added into the grid.

“Customer conservation is going to be the single biggest variable this summer to whether or not we are able to avoid rotating outages,” Mainzer said during a press conference before touring the Top Gun site.

If utility customers respond to Flex Alerts and other calls to voluntarily conserve electricity when necessary, as they did last August and September and again during an extreme heat wave in mid-June, the grid can get through summer without outages to reduce demand, he said.

“If we don’t get that kind of response,” Mainzer told about 20 reporters at the event, “it could be a different story . . . I can’t over-estimate the importance of that message.”

SDG&E’s Winn also stressed the public’s role in keeping electricity flowing during the hot summer months when demand rises primarily from air conditioners across the region.

“It really takes all of us to keep the grid running smoothly, especially with the climate change impacts that we’re facing and the more extreme weather conditions,” she said. “These transmission lines are all inter-connected throughout California and throughout the West, so if something happens elsewhere in California, we likely will be impacted. And if something happens here, other parts of California will be impacted.”

The Top Gun facility consists of 36 custom-made shipping containers filled with more than 15,000 lithium-ion batteries that can power up to 25,000 homes for four hours. That kind of capacity is essential during extreme heat events when demand remains high in the evening, typically from 4 p.m. to 9 p.m.

“Five years ago, we were just talking about the ability to store electricity, and now by the end of this year, next year, we’ll triple the capacity of energy storage we’ll have in our system,” Winn said. “This is a really exciting time to think about all the clean energy that’s coming from the sun and the wind and to be able to store that electricity for use when the sun stops shining and be able to meet the demand in this state.”

New technologies and demand-response programs that encourage customers to conserve “really bolster our ability to withstand the challenges we will face not only this summer but in the summers ahead . . . ,” Winn added. “The number of weather events that we’ve seen really put an extreme stress on the grid and it’s not just here in California, it’s throughout the Western United States.”

When electricity supply and demand are not balanced, Flex Alerts may be issued asking consumers to set home thermostats at 78 or higher, avoid using major appliances and turn off unnecessary lights. Those steps, taken collectively, ease pressure on the grid. Consumers are also encouraged to pre-cool their homes, charge electric vehicles and other devices earlier in the day, when solar power is abundant.

Because the Western states are also dealing with prolonged drought conditions that have reduced hydroelectric power in California and the West, Mainzer said a stable grid is now considered more challenging than anticipated just two months ago when the ISO’s annual Summer Assessment was released. At the time, he used the term “guarded optimism” regarding the ISO’s outlook for the summer.

“In the last several weeks, we’ve seen significant heating events across the West and changes in the hydro conditions (and) I think we’re adding just a little bit more’ guarded’ to that guarded optimism,” he said. Acknowledging that consumers are inconvenienced when they are asked to change their habits, Mainzer emphasized the need for candid information about conditions that grid operators deal with.

“We try to provide just the best possible information—accurate, objective, intellectually honest information—we possibly can to Californians about the state of the grid because it’s really only through a factual and objective analysis and readiness that we can be prepared.”

With June temperatures already reaching triple digits across California and in places like Portland and Seattle, along with some supply chain-related delays in bringing new resources online this summer, Mainzer said the ISO is using every tool it has to promote reliability.

“But equally importantly or in some ways almost more importantly,” he added, “we’re focusing on the demand side of the equation because when our grid gets into stressed conditions, that’s when we really need consumers and industry across California to be part of the reliability equation.”

Back to top