Assembly Committee Holds Oversight Hearing on California’s August Electricity Outages

Tuesday, October 13, 2020

Sacramento (CA) – The California State Assembly Committee on Utilities and Energy, chaired by Assemblymember Chris Holden, held an oversight hearing to discuss the August 14th and 15th electricity outages and the Preliminary Root Cause Analysis prepared by the California Independent System Operator (CAISO), California Public Utilities Commission (CPUC), and the California Energy Commission (CEC).

“A reliable power system underpins our economy and quality of life,” said Assemblymember Chris Holden.  “The outages that occurred in August breached our confidence in the California Public Utilities Commission, California Independent System Operator and the California Energy Commission’s ability to carry out their responsibilities to ensure that residences and businesses have reliable electric services.”

Presenters of the Preliminary Root Cause Analysis Report included Marybel Batjer, President of CPUC; David Hochschild, Chair of CEC; Steven Berberich, former President and CEO of CAISO; and Elliott Mainzer, current President and CEO of CAISO. The presentation slides can be found here.

“The energy principals have rightfully assumed responsibility for the hardship that many in this state endured when the broad scale rotating outages occurred in mid-August.  We hold them accountable for not just identifying the shortcomings, but, most importantly, to promptly and systematically take actions to mitigate the outstanding issues,” said Holden.

The full hearing can be viewed at

In mid-August, for the first time in 20 years, the California Independent System Operator directed utilities to trigger rotating outages. The event was due to confluence of events and regulatory shortcomings that led to a shortfall in available supply to meet demand.

The broad scale de-energization took place with little to no public warning. On those dates, there was a rare West-wide heat storm, which affected both the demand and supply of generation. The multi-day heat storm meant that there was limited overnight cooling, so air conditioners continued to run well into the evening and the next day. The heat storm occurred as fires raged throughout the state and in the midst of a global pandemic.

In an August 17, 2020, letter to the energy organizations CEC, CPUC, CAISO, Governor Gavin Newsom called upon those entities to conduct a root-cause analysis into the rotating outages.

On October 6, 2020, the energy organization released a preliminary root-cause analysis. The analysis identified several factors that, in combination, led to the need for the CAISO to direct utilities in the CAISO footprint to trigger rotating outages. There was no single root cause of the outages. 

The contributing factors identified in the energy organizations preliminary root-cause analysis include:

The climate change-induced extreme heat storm across the western United States resulted in the demand for electricity exceeding the existing electricity resource planning targets. The existing resource planning processes are not designed to fully address an extreme heat storm like the one experienced in mid-Augus
In transitioning to a reliable, clean, and affordable resource mix, resource planning targets have not kept pace to lead to sufficient resources that can be relied upon to meet demand in the early evening hours. This makes balancing demand and supply more challenging. These challenges were amplified by the extreme heat storm.
Some practices in the day-ahead energy market exacerbated the supply challenges under highly stressed conditions.
“I am putting the energy organizations on notice that this Committee is seeking regular updates and progress reports on the implementation of actions addressing the deficiencies identified in the preliminary root-cause analysis and the final report.   Further, we will at a minimum, hold a hearing prior to next summer into summer readiness,” continued Holden.