California's beleaguered and largest underground natural gas storage field sat unused in recent days as Southern California battled its first heat wave of the summer in which triple-digit temperatures prevailed in the inland valley and desert regions.

While dealing with heat-related outages that affected nearly 50,000 of its 1.5 million electricity customers, the Los Angeles Department of Water and Power (LADWP) did not tap any of the available, albeit limited, natural gas supplies in the 3,200-acre Aliso storage facility, an LADWP spokesperson told NGI on Tuesday. LADWP set daily record power sendouts on two days between Friday and Tuesday. 

In total, LADWP relied on 15 of its gas-fired power generation units, which produced more than 3,200 MW of electricity to meet loads that exceeded 5,000 MW. "These units generated more than 165,000 MWh of power over the four-day period,” the spokesperson said.

As of Sunday, LADWP said it had restored power to 57,000 customers. But the circuit overloading slowed the restoration progress and led to recurring outages in some neighborhoods, the spokesperson said.

Aliso owner Southern California Gas Co. (SoCalGas) issued a four-day systemwide gas curtailment watch for its territory and that of sister Sempra Energy utility, San Diego Gas and Electric Co.

"Although locally stored natural gas can help support the system during such an event, current rules require SoCalGas to curtail electric generators prior to using gas stored at the Aliso Canyon facility," a SoCalGas spokesperson told NGI on Tuesday regarding state rules. "Electric generators were not curtailed over the past four days of heat."

Under the existing protocols, noncore customers would have been required to reduce gas use if a curtailment had been issued. If that had happened, Aliso would have been used to support energy reliability before other noncore customers were directed to curtail their gas use, according to the spokesperson.

Earlier this month, California regulators ordered SoCalGas to increase the range of working gas volumes to 34 Bcf at the Aliso Canyon facility. The California Public Utilities Commission in its summer supplemental report cited the current "unprecedented level of outages" on the SoCalGas pipeline system as contributing to the need to increase Aliso volumes, which have been restricted for the past three years since the storage well leak that lasted four months.

Separately, California also recently finalized regulations for underground gas storage aimed at public health and safety nearly three years after the methane leak at Aliso. The regulations, which are set to take effect Oct. 1, would replace emergency rules that took effect in early 2016.