On August 19, 2020, officials from California Independent System Operator (CAISO), the California Public Utilities Commission (CPUC), and the California Energy Commission (CEC) sent a letter to California Governor Gavin Newsom regarding the power outages of August 14 and 15 that were triggered due to insufficient resources.[1] According to the letter, CAISO anticipated high loads and temperatures beginning on August 14, so it issued an order restricting maintenance operations on August 12, an alert identifying a possible system reserve deficiency on August 13, and a Flex Alert[2] for August 14. However, on the afternoon of August 14, the situation deteriorated due to a developing, historic west-wide heatwave. The imbalance in supply and demand forced utilities to turn off power to their customers during the evening of August 14. On August 15, CAISO experienced similar conditions which led to further shutoffs. In the near term, CAISO expects that energy demand will remain high as the heatwave persists.

CAISO recognized that although the specific situation could not have been predicted, better communications and advance warnings should have been implemented. In their letter, the regulators pointed to capacity shortfalls and California's heavy reliance on importing resources to meet its energy demand in the summer as key factors in the blackouts. The regulators stated that they will need to perform a deep dive into the issue to make sure reliability resources can be available to address unexpected grid conditions.

[1]https://www.cpuc.ca.gov/uploadedFiles/CPUCWebsite/Content/News_Room/NewsUpdates/2020/Joint%20Response%20to%20Governor%20Newsom%20Letter%20August192020.pdf

[2] A Flex Alert is a call for consumers to voluntarily conserve electricity when there is a predicted shortage of energy supply