Solar-plus-storage has a 99.8% capacity value in California
“The energy from solar can consistently charge a 4-hour storage device having the same installed capacity” prior to the hours of peak demand, says a new study. In Arizona and New Mexico the capacity value is 99%.
Solar-plus-storage has 99.8% of the capacity value of a theoretical “perfect generator” in California’s CAISO grid region.
That’s the finding of a study commissioned by California’s three major utilities, based on a 500-MW solar farm paired with 500 MW of 4-hour storage, with a 500-MW interconnection.
A similar result emerged from a study of stand-alone storage in the PJM grid region, which found that 4 GW of 4-hour storage could provide capacity of “equivalent reliability value” to that supplied by conventional power plants in PJM.
Both the CAISO and PJM studies were conducted by Astrapé Consulting.
The California study found solar-plus-storage capacity values in the CAISO region would gradually decline to 93.2% by 2030, as storage capacity in the region grows from 1.1 GW to 3.4 GW, based on the utilities’ resource plans.
Added storage reduces the capacity value of solar-plus-storage because as storage lowers the peak load, it broadens the duration of the peak period beyond four hours.