California’s power grid is expected to make it through the summer with some energy reserves left over, but a long-term plan is needed to backfill power lost by the closure of the San Onofre Nuclear Generating Station, state and utility officials said Wednesday.
In a hearing held in Sacramento, the Senate Committee on Energy, Utilities and Communications heard testimony from officials with Southern California Edison, San Diego Gas & Electric, the California Energy Commission, the California Independent System Operator and the state Public Utilities Commission.
“The announcement of the plant’s retirement presents a tremendous challenge for all of us,” said Sen. Alex Padilla, D-Pacoima, the committee’s chairman. “We need to keep the lights on, and as with any challenge we must address the situation and gather all relevant information. It requires a careful consideration of our portfolio of energy options.”
David Mead, senior vice president of transmission and distribution planning for Edison, said his utility’s energy mix has changed with the closure of San Onofre and that natural gas and other unspecified power sources will be used to make up the difference. The closure of the plant has left a deficit of more than 2,000 megawatts of energy.
The nuclear facility has been offline since January of 2012. Mead said Edison’s San Onofre staffing will be reduced from 1,500 to 400.
“Last year when we were preparing for the summer, knowing we wouldn’t have SONGS, we were able to bring gas-fired generators in Huntington Beach back online,” he said. “That allowed us to have a generation resource available for the area. It made a big difference, but this year we converted those to synchronous condensers to keep the system stable without the generation of greenhouse gases. We turned it into something that can benefit the system.”
Other modifications to the power grid also have been made to accommodate the loss of San Onofre. Substations in Santiago, Johann and Viejo have had capacitors added, which also support voltage. Transmission lines have likewise been reconfigured from two circuits to four circuits to provide greater flexibility, and new gas-fired generation plants are up and running in El Segundo (564 megawatts), Sentinel (800 MW) and Walnut Creek (500 MW).
Robert Weisenmiller, chairman of the California Energy Commission, said the state will likely have enough power to address most scenarios that occur this year.
“The basic message is we, the ISO and the utilities all agree that the statewide supply is adequate to cover a broad range of conditions,” he said. “But with the loss of San Onofre the key issues range on San Diego County and on reactive power. It’s time that all of us move forward to figure out where we’re going in terms of replacement.”
Cal ISO estimates that Southern California will have an energy reserve of about 23 percent this summer, assuming normal conditions. But under extreme conditions of reduced capacity and high demand that margin could be shaved to 6 percent, officials said.
The San Onofre plant has remained offline since January 2012 when one of the facility’s steam generators sprang a leak and released traces of radiation. The leak occurred because of excessive vibration and friction among tubes that carried radioactive water through the plant’s steam generators.
Edison made repairs and submitted a restart plan to the Nuclear Regulatory Commission in October. The plan was under consideration by the NRC, but Edison announced last month that it decided to permanently shutter the plant as it not cost-effective to wait any longer.
Future hearings on San Onfre will discuss safety concerns, the facility’s decommissioning process and possible rebates to ratepayers, among other issues.