The California Public Utilities Commission on Aug. 27 unanimously signed off on Pacific Gas and Electric Co. and Southern California Edison Co. entering into contracts for 1,106 MW of battery storage facilities in order to maintain resource adequacy.

CPUC Energy Division Director Edward Randolph said the commission approved Pacific Gas and Electric's, or PG&E's, contracts for 423 MW of battery energy storage from five projects and SCE's contracts for 683 MW of battery energy storage from seven projects. Both sets of projects must achieve commercial operation on or before Aug. 1, 2021.

Just before the commissioners approved the energy storage contracts, Randolph said the agency will extensively examine the causes of the Aug. 14 and Aug. 15 power shortages that caused rolling blackouts for hundreds of thousands of customers in California with little or no notice. "Based on our planning process, there should have been enough available supply to meet demand," he said. "So energy agencies need to make changes to prevent that."

The contracts were signed in keeping with the commission's late 2019 order mandating that load-serving entities procure 3,300 MW of new capacity to meet a shortfall of resources, Randolph said. The commission directed the state's investor-owned utilities to conduct all-source solicitations that would consider existing as well as new resources, demand-side resources, combined heat and power, and storage.

The lists of selected projects and their developers were outlined in the commission's resolution approving PG&E's contracts and a separate resolution approving SCE's contracts.

PG&E is a subsidiary of PG&E Corp. and SCE is a subsidiary of Edison International.