A combination of the permanent retirement of the San Onofre Nuclear Generating Station (SONGS) by Southern California Edison and the need to retire mostly gas-fired capacity due to once-through cooling (OTC) rules, is creating a power supply and transmission crunch in the Los Angeles area.
The California Energy Commission and the California Public Utilities Commission held a July 15 joint workshop on issues created by the SONGS retirement. SONGS was actually offline when Southern California Edison (SCE) decided not to try and reopen it, so the lack of that power plant is already being felt in the region.
Phil Pettingill, Director, Regulatory Strategy at the California ISO, was one of the presenters at the workshop. One of his points was to outline how a number of plants are mandated to eliminate once-through cooling on a schedule decided before the decision to retire SONGS.
Authorized procurement of new power suppliers was based upon analyses that included SONGS online through 2022. The ISO and the CPUC are currently developing new scenarios that exclude SONGS, Pettingill noted.
One of his slides, titled “OTC retirements and SONGS closure create local capacity shortfalls,” broke down authorized OTC replacements in three sub-regions in Southern California.
Big Creek/Ventura (northwest of Los Angeles along the Pacific Coast):
- OTC installed capacity of 1,946 MW;
- 2020 need of 430 MW, with 215 MW-290 MW already authorized;
- OTC-affected plants Mandalay and Ormond Beach in the to-be-determined category on OTC compliance.
Los Angeles Basin:
- OTC installed capacity of 4,476 MW;
- 2022 need of 3,460 MW-4,615 MW, with 1,400 MW-1,800 MW authorized;
- OTC-affected El Segundo plant partially repowered, with Redondo Beach, Alamitos and Huntington Beach in the to-be-determined category (SONGS is in the southeast end of this region).
- OTC installed capacity of 946 MW;
- 2018 need of 1,120 MW, with 343 MW authorized;
- OTC-affected Encina plant in the to-be-determined category and the South Bay plant is retired.
Pettingill noted that the ISO’s preliminary conclusions at this point are:
- Loss of SONGS creates transmission impacts (thermal overloading, voltage instability) in LA Basin and San Diego LCR areas;
- Possible mitigations for SONGS have been explored, including preferred resources, transmission, conventional generation; and
- Consider contingency plans to ensure overall success.
Pettingill runs down various possible responses for each of the next few summer high load periods.
For example, in the summer of 2018, the San Diego area needs a significant increase beyond the impact of load growth and potential retirement of Encina (946 MW) in December 2017. Possible mitigations include: acquire additional resources in San Diego sub-area; possible extension of Encina OTC compliance date; and 1,120 MW of resources if distributed within San Diego.
For the summers 2021 and 2022, the LA Basin area needs a significant increase beyond load growth impacts and potential retirement of 3,800 MW in December 2020. Mitigation possibilities include: acquire additional resources in LA Basin and San Diego (4315–4615 MW in LA Basin or 3,800 MW in LA and 800-900 MW in San Diego or 3,000 MW in LA and 600 MW in San Diego) with major transmission reinforcement (about 1,000 MW local resource capacity reduction).
Local utilities outline their SONGS alternative planning
Mark Nelson, Director, Integrated Planning & Strategy at SCE, said that a number of summer readiness projects, coupled with new generation coming on line from prior solicitations, is supporting local reliability for Summer 2013. Projects completed include: the installation of four 79.2 MVAR 200-kV capacitor banks at three Orange County substations; decoupling the two 230-kV Barre-Ellis into four lines; and converting Huntington Beach Units 3 and 4 to synchronous condensers. About 1,775 MW of new generation capacity will be coming online this summer: Walnut Creek (June 1), CPV Sentinel (Aug. 1) and El Segundo (Aug. 1).
Over 8,000 MW of generation resources in the SCE service territory have retired or could retire between now and 2020, Nelson said in his presentation. That includes 6,257 MW of fossil-fired capacity and 2,150 MW at SONGS. The OTC compliance years for the plants in the SCE region are:
- Alamitos 2020
- El Segundo 2015
- Huntington Beach 2020
- Mandalay 2020
- Ormond Beach 2020
- Redondo Beach 2020
San Diego Gas & Electric (no name of a utility official given on the presentation, but utility official Will Speer listed on the agenda) outlined at the workshop various transmission, generation and other things it is doing to enhance system reliability. It noted that it is proposing the Pendleton Energy Park, which would be up to 1,000 MW of generation capacity on Camp Pendleton. That project would be competitively bid to independent generation developers to own and operate peaking plants as the need is identified in the long-term planning process.
“Without SONGS, the SDG&E and the southern SCE systems are more dependent on each other,” the SDG&E presentation said. “Optimization of replacement generation and transmission infrastructure between the San Diego and Los Angeles areas is crucial for minimizing ratepayer impacts.”