(Bloomberg) -- One of the rare beneficiaries of an unprecedented blackout that may plunge more than 3 million Californians into darkness this week: the backup power business.

Suppliers of backup, diesel-fired generators, solar panels, batteries and fuel cells alike see a sales opportunity in the massive power shutoffs rolling out across the San Francisco Bay Area. Home solar provider Sunrun Inc. said hundreds of customers were spared from recent planned shutoffs because of their solar panels and batteries -- and it expects that to number to be in the thousands after this week’s blackout.

“With solar and storage, your monthly expenses go down and you get more reliable power 365 days of the year,” Ed Fenster, chairman of the San Francisco-based solar installer, said.

The widespread shutoffs that bankrupt utility giant PG&E Corp. has been orchestrating to keep its power lines from igniting more devastating -- and costly -- wildfires are shining a light on the need for more on-site power, known as distributed generation. Environmentalists took advantage of the outages on Wednesday to promote more local wind, solar and battery resources.

“Turning out the lights for weeks at a time will become the new normal for California residents unless the state takes action to build a more sustainable energy system,” said Alexandra Nagy, state director of the environmental group Food & Water Action.

Fuel cell manufacturer Bloom Energy Corp., which is based in San Jose, California, said it has also seen sales leads double in the past two months, in part because of the power dilemma.

“We deal primarily with commercial and industrial customers, and they are beginning to see this as the new normal,” Asim Hussain, Bloom’s vice president of commercial strategy and customer experience, said in an interview. “With one days notice they could be faced with a multiple-days outage situation.”

Aaron Jagdfeld, chief executive officer of backup generator supplier Generac Holdings Inc., said the widespread shutoffs that PG&E was carrying out this week will “create a huge influx in demand” for the company’s products. The Waukesha, Wisconsin-based generator supplier surged 9.1% to a record as PG&E started cutting service to as many as 800,000 customers Wednesday.

Michael Halloran, an analyst at Robert W. Baird & Co., called the blackouts “critical to Generac’s ability to penetrate” the home standby generators market.

--With assistance from Mark Chediak.

To contact the reporters on this story: Christopher Martin in New York at cmartin11@bloomberg.net;Nic Querolo in New York at jquerolo1@bloomberg.net

To contact the editors responsible for this story: Lynn Doan at ldoan6@bloomberg.net, Dan Reichl

©2019 Bloomberg L.P.