In the early 2000s, after market deregulation and Enron’s notorious manipulation of gas supplies led to blackouts and financial instability among the power companies, state officials decided to lessen reliance on natural gas by encouraging the development of wind and solar.

Under Mr. Schwarzenegger, who was governor until 2011, officials pushed through a raft of overlapping regulations that created a boom in renewables, especially solar. But that upended the traditional patterns of supply and demand, making the overall energy system technically and economically difficult to manage.

Batteries were the logical solution. But the technology wasn’t fully developed and was still too expensive. In order for companies to make the necessary investments, they needed a signal that there would be a big enough market for their products.

So in 2010, the state approved one of the first energy-storage mandates, ultimately requiring utilities to install some form of storage equipment in their territories. That set off a flurry of new investment and innovation and, after the sudden closure of the San Onofre nuclear plant on the coast in northwest San Diego County in 2012 when a steam generator tube sprung a leak, new contracts for battery installations.

But the Aliso Canyon accident, which began on Oct. 23, 2015, when the Southern California Gas Company first detected the leak, put that process on fast-forward. The noxious-smelling gas and intermittent oily mist that spewed forth over almost four months traveled into the surrounding neighborhoods on the strong winds that sweep down from the Santa Susana Mountains. At the same time, it forced the battery strategy into its most high-profile test yet.

Now it’s showtime, and the pressure to succeed is high all around. For AES, it could signify an important step for a long-troubled conventional-energy relic that is seeking to revitalize itself as a powerhouse in battery storage and other advanced technologies.

For clean-energy advocates — including residents of the Porter Ranch section of Los Angeles, so picture-perfect that Steven Spielberg chose it as the setting for the 1982 movie “E.T.,” but where many still complain of the rashes, headaches and other debilitating symptoms that drove thousands from their homes during the leak — it could be a powerful weapon in the fight to keep the gas depot closed.