A handful of upgrades to Southern California’s electric power grid are in the works to address reliability issues that could arise from the permanent closure of San Onofre Nuclear Generating Station (SONGS).
Plant operator Southern California Edison (SCE) decided June 7 not to reopen the nuclear power plant, and officials with the California ISO (Cal-ISO) predicted that the state as a whole would be in “reasonably good shape this summer, even without SONGS'” 2,200 MW of generating capacity, except in southern Orange County and in San Diego, where Cal-ISO expected transmission constraints to result in challenges to importing the power needed.
The projects, many of which are aimed at alleviating those constraints, were presented to the ISO’s board of governors in February and have either been completed or are nearing completion by the various companies and utilities involved.
Projects include the conversion of Huntington Beach generating units 3 and 4 into synchronous condensers. Cal-ISO CEO Steve Berberich said on June 7 those condensers are scheduled to come online on June 26, ahead of the above-average temperatures some are already forecasting for the area during July and August.
System upgrades include additions to several substations. Additional 80 MVAR capacitors at SCE’s Santiago and Johanna substations and a 160 MVAR capacitor at the Viejo substation are operational.
Two San Diego Gas & Electric (SDG&E) substations will also see enhancements. A 230/138 kV transformer will be added to the utility’s Encina substation just south of San Onofre and a 230 kV capacitor will be added to its Penasquitos substation this summer. Other system upgrades, including the 2012 energization of the Sunrise PowerLink, have already increased SDG&E’s import capacity from 2,100 MW on June 17, 2012, to 3,350 MW today, an SDG&E spokesperson told TransmissionHub June 12.
Another project involves an upgrade to the Barre-Ellis 220-kV transmission line, which will be split from two circuits into four to provide additional redundancy. Approved in 2012, the project has been fast-tracked and is expected to be completed by June 15, a Cal-ISO spokesperson told TransmissionHub.
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