California ISO Survives the Summer with No Blackouts; Battery Energy Storage Beginning to Play Larger Role
The California ISO held its final Summer 2021 Readiness Update call on September 24. As reported on the call, the California ISO managed to get through summer 2021 without any load-shedding events, in contrast to last summer, when load-shedding events occurred on two days in August. The California ISO; California energy regulatory agencies, including the California Public Utilities Commission (CPUC) and California Energy Commission (CEC); and the Governor’s office have spent considerable effort to avoid any outages for both this summer and summer 2022. However, as California ISO Senior Vice President and Chief Operating Officer Mark Rothleder explained, California experienced less extreme weather this summer, which helped the state avoid outages. Although July was challenging, due to a West-wide heatwave and transmission impacted by the Bootleg Fire, August and September were more mild. In 2020, load peaked at 47,121 megawatts (MW) on August 18, at 15:57. In 2021, load peaked at 43,982 MW on September 8, at 17:50. By comparison, the California ISO’s highest peak was 50,270 MW in 2006.
As illustrated by the timing of the load-shedding events last year, the California ISO’s greatest challenge is meeting load in the late afternoon and early evening, when solar generation comes off the system as the sun goes down. Battery storage can be an important part of the solution—charging during the day when there is plentiful solar generation and energy prices are low, and then discharging during the evening peak, when solar is no longer available….