California regulators recently approved the replacement of a coastal natural gas-fired baseload power plant with gas-fired peaking units as a statewide ban on seawater cooling for coastal plants draws closer.

Princeton, NJ-based NRG Energy Inc. has three of the sites involved in various regulatory and legal proceedings for existing gas-fired baseload plants along the Southern California coast: two in Ventura County and the other in North San Diego County.

NRG is pointing to a resolution of legal challenges to convert the Encina Plant site in Carlsbad in San Diego County to an array of fast-start gas-fired peaking units by the first quarter of 2018, and it is targeting replacement of some 2,076 MW of baseload plants at two sites in Ventura County into a similar peaking array by the start of 2021.

The California Public Utilities Commission (CPUC) in late May approved NRG’s plans for the 262 MW Puente Power Project as a replacement for the Ormand Beach (1,516 MW) and Mandalay Bay (560 MW) gas-fired, seawater-cooled baseload generation plants by the end of 2020. CPUC approval came over opposition from local residents and elected officials in Oxnard, near the proposed peaking plant site on part of the Mandalay land.

Puente now goes to the California Energy Commission (CEC) for review and approval, and the local opposition in Oxnard has vowed to ask the five-member CEC to reject the project. NRG has countered that putting the peaking units on part of the old site will allow the use of vacant brownfield land and existing natural gas transmission pipelines.

“We expect that sometime in early 2017 that we will get a decision for the CEC,” said a Houston-based NRG spokesperson. The CEC last summer approved NRG’s Carlsbad Energy Center Project for part of its existing 100-acre Encina power plant site (see Daily GPI,Aug. 3, 2015), and the CPUC earlier OK’d the project (see Daily GPI,May 27, 2015).

Nevertheless, those approvals are currently being tested in a state appeals court due to challenges from various environmental groups.

The CEC approved the building of the new facilities, and the CPUC approved a power purchase and tolling agreement with the local utility San Diego Gas and Electric Co. and NRG’s proposed five-unit, 500 MW gas-fired peaking facility that would replace the outdated, larger existing baseload generation plant at the site. A similar deal with Southern California Edison Co. was approved for the Puente project.

“For Carlsbad, we are awaiting a final, unappealable decision from the courts before we make the decision to move forward,” the NRG spokesperson told NGI on Friday.

Under the heading of “once-through-cooling” the technology applied to the coastal plants built 40 to 60 years ago, up to 17 gas-fired plants along California’s coast have remained the main focus of the state’s water cooling restrictions adopted six years ago by the California Water Resources Control Board in close collaboration with the state’s major energy agencies (see Daily GPI,May 10, 2010).

The arcane rules were approved after five years of analysis, a full day of testimony from staff and stakeholders, and the clarification of 17 last-minute amendments that applied individual target closure dates for each coastal power plant.

NRG’s other coastal power generation site at El Segundo near Los Angeles International Airport was repowered several years ago and now meets the latest requirements calling for air cooling. For the remaining plants, “everything is based on OTC timetables,” the NRG spokesperson said.

“The El Segundo Energy Center has already been built and has two large combined-cycle gas-fired units [550 MW] there,” he said. noting the new units replaced the old Units #1 and #2, and the old Units #3 and #4 have been retired, but have not been dismantled yet, pending possible green power or other development on that portion of the site.