Environment & Science

Fallout from Porter Ranch gas leak could trigger up to 32 days of blackouts, energy officials say

The sun shines over towers carrying electrical lines.
The sun shines over towers carrying electrical lines.
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Los Angeles and surrounding counties could see power outages during as many 32 days over the coming year as a result of the troubled natural gas storage facility at Aliso Canyon, now mostly offline in the wake of a four-month gas leak. Fourteen of those days could fall during the hottest days of summer.

Those predictions came Tuesday from the heads of three state energy agencies and officials with the L.A. Department of Water and Power.

“The limited current operations of the facility create the distinct possibility of electricity service interruptions in the coming summer months,” said Mark Rothleder, vice president of the California Independent System Operator (Cal-ISO), which coordinates power distribution among various utilities.

"The question for this summer is what is the weather," said Robert Weisenmiller, chairman of the California Energy Commission. "If we have hotter-than-anticipated weather, that will put more stress on the system.”

As many as 18 power plants in the region rely on natural gas to fire turbines and generate electricity. Much of that gas comes from the Aliso Canyon storage facility, which has been idled while investigators test the safety of more than 100 gas wells.

In October, a well at the facility ruptured and spewed an estimated 100,000 metric tons of natural gas into the air. It took four months to seal and has raised questions among regulators about the safety of other wells.

As spring transitions to summer, energy officials are worried that heat-driven spikes in electricity demand could trigger blackouts because there won't be enough gas in the system to meet the demand. The region's grid of gas supply lines only holds about three-to-four days worth of natural gas during times of peak demand.

“Natural gas pipelines  that bring gas into the L.A. Basin cannot meet the peak energy demands without Aliso Canyon gas storage," Rothleder said. "These pipelines also cannot transport gas fast enough to meet the hour-by-hour or changing demands of power plants during the summer when electric demand peaks."

Rothleder added, "Without any gas supply from Aliso Canyon, there are up to 14 days this coming summer during which gas curtailments could be high enough to cause electricity service interruptions to potentially millions of utility customers."

The California Energy Commission's Weisenmiller said the outages probably wouldn't be rolling blackouts but "scheduled outages" that could give limited advance warning.

The root of the  problem is that much of Southern California's peak-demand energy supply is generated using gas-fired power plants, and gas may be in short supply because the main place it is stored underground is mostly out of commission. The uncontrolled leak of a gas well near Porter Ranch from October through mid-February led Gov. Jerry Brown and state regulators to order its use minimized.

The Aliso Canyon storage facility, operated by Southern California Gas Company, is being kept at 15 billion cubic feet of gas. That is less than one-fifth of its normal capacity. The plan is for it to remain at that low level while the wells are being inspected.

In a statement, So Cal Gas said Tuesday's announcement underscored the importance of natural gas to the region's power supply.

“The action plan recognizes the crucial role Aliso Canyon plays in providing reliable energy service to Southern California, and we appreciate that the agencies responsible for developing the plan understand that steps need to be taken to deal with our inability to rely on Aliso in the near term," the statement said.  

With a state moratorium barring injections of gas, the region's supply of natural gas is extremely limited.

A draft plan for avoiding or minimizing power outages in L.A. and surrounding regions during expected gas shortages was released Tuesday. It's a joint effort by the California Energy Commission, the CPUC, Cal-ISO and the L.A. Department of Water and Power. It contains measures to conserve gas and electricity in hopes of avoiding outages.

Many of the measures are expected to add to the cost of the gas and electricity. CPUC chairman Michael Picker said privately-owned utilities regulated by the CPUC would not be permitted to raise their rates without explicit permission from the agency. He added that utilities should keep track of added expenses and seek reimbursement from SoCal Gas's billion dollars worth of insurance policies.

“For the costs that we currently see and have been reported to us, they are well within SoCal Gas’ insurance limits and they will probably be picked up by their insurance company,” Picker said.

Among the consumer-facing measures the agencies are proposing:

For its part, the LADWP plans to shore up its power supplies by not selling electricity to others.
It will also turn to alternate, more expensive forms of generating power when the gas supply is scarce.

Power companies will be asked to carefully estimate the amount of gas they need each day to avoid shortages. If they mistakenly order less than they need, or if there is a sudden heat wave, then less gas would be in the system than generators want. That means the entire system could run short of gas.

The draft report calls for prudent use of the remaining gas stored in the Aliso Canyon underground reservoir.