California regulators on Tuesday extended the life of four coastal natural gas-fired power plants slated for retirement this year.

The plants had been scheduled to be closed as part of a decade-old effort to eliminate sea water-cooled plants. 

The California Water Resources Control Board action occurred after a series of rolling blackouts to manage the grid in the midst of a record heat storm and wildfires. However, the board began reviewing the extensions a year ago after a potential electric system shortfall of up to 4,400 MW beginning summer 2021 was identified.

The board’s resolution extended the compliance dates “to address grid reliability concerns as new energy procurement comes online” over the next three years. 

Three AES Corp. plants to run through 2023 are Long Beach (1,216 MW Alamitos), Huntington Beach (450 MW) and GenOn-operated Oxnard (1,516 MW Ormond Beach). The Redondo Beach (1,300 MW) plant was extended to run through 2021.

The Pacific Gas and Electric Co. Diablo Canyon Nuclear Generating Station Units 1 and 2 also were extended to run until separate dates in 2024 and 2025, respectively.

Board Chair E. Joaquin Esquivel said the decision to extend operations would balance the “real needs for grid reliability against what are also very real water quality and protection needs.” He also acknowledged the “complicated local political landscapes” in which each of the plants operate.