The California Public Utilities Commission (CPUC) plans to consider two proposals to increase allowable working gas capacity at the Aliso Canyon natural gas storage facility in Los Angeles County.

The proposals are meant to ensure sufficient supplies this winter for gas and electric customers in the Los Angeles Basin, CPUC said last week. The currently allowed maximum capacity is 34 Bcf, less than half the 86 Bcf limit in place prior to a massive 2015 methane leak at the site.

“As we transition to a clean energy economy, we need to ensure energy reliability,” said CPUC commissioner Martha Guzman Aceves. “We must do so in a manner that does not detract from our mandate to ultimately reduce our reliance on natural gas infrastructure like Aliso Canyon.”

An administrative law judge has proposed authorizing Aliso’s owner/operator, Southern California Gas Co., to increase working gas storage capacity to 68.6 Bcf. This is the maximum amount allowable to ensure safe operations, according to the California Geologic Energy Management Division.

Guzman Aceves, meanwhile, is proposing a more modest increase to 41 Bcf.

“The 41 Bcf limit is safe and reliable, and it will allow us to get through this winter while we continue our progress toward planning how to reduce or eliminate our use of Aliso Canyon by 2027 or 2035, or anytime in between,” she said.

Why Would Aliso Close?

CPUC is scheduled to vote on which proposal to approve at a meeting set for Nov. 4.

The proposals are part of a larger proceeding underway to determine the feasibility of closing Aliso to meet the state’s climate change goals. Officials are evaluating the most effective ways to maintain energy reliability if it were to be closed. 

In late September, Gov. Gavin Newsom signed into law a bill to accelerate deployment of clean zero-carbon electricity resources to ensure grid reliability on the path toward decarbonization.

However, California’s energy system has been strained by extraordinarily hot and dry conditions, limiting hydroelectric output and putting infrastructure at risk of damage by wildfires.

The U.S. Department of Energy recently approved a request by the California Independent System Operator (CAISO) to dispatch additional natural gas-fired generation capacity beyond permitted levels to make up for potential shortfalls.

CPUC has engaged FTI Consulting Inc. to model different scenarios to guide potential paths to replace Aliso, the commission said. FTI plans to present its findings at a public workshop on Nov. 3 and issue a report by year’s end, CPUC added.

CPUC, CAISO and the California Energy Commission also are developing the 20-Year Transmission Outlook, which would review how the transmission system will need to change to meet the goal of a 100% carbon-free power sector by 2045. The study is to examine scenarios that include the unavailability of Aliso, CPUC said.