SolarCity has a new home in the South Bay.

The solar panel installation giant has moved from a 10,000-square-foot facility in Westchester to a warehouse in Hawthorne, where 12 installation crews will eventually be working seven days a week to keep up with demand.

“I’m on call 24/7,” said Oswaldo Acosta, the regional operations manager.

With 168,000 customers, SolarCity is the largest solar panel installer in the country. The company first arrived in the South Bay in 2007, with 25 employees working out of a location in Westchester. The company now has locations at 4884 W. 145th St. in Hawthorne, 21040 Nordhoff St. in Chatsworth and 5375 W. San Fernando Road in Atwater Village.

The Hawthorne facility, which has about 240 employees, will cover 46 cities in Southern California. About 160 of those employees are in sales.

Jim Cahill, SolarCity’s regional vice president for California and Hawaii, said the company plans to dig deeper into the communities it already serves.

“It’s kind of a numbers game,” Cahill said. “The more sales people we have in the area, the more growth we see in those areas.”

Acosta, a U.S. Army veteran who joined SolarCity in 2009, said business has doubled every year since he started working for SolarCity in 2009.

A typical, 20-panel installation in the South Bay used to take about three days. Now, it takes about four hours, thanks to snap-together panel technology, Acosta said.

The company is looking forward to the implementation of AB 2188 in January, when cities will be forced to speed up the permitting process for solar installation.

It now takes up to three months from sale date to solar panel activation, due to regulatory hurdles. The company hopes to reduce that to 30 days.

Cahill said he sees SolarCity’s explosive growth continuing because solar is still such a small fraction of the overall energy market.

One way that Cahill gauges the popularity of solar is by looking out the window when he flies in and out of Southern California.

“For the first three years I flew out of Burbank monthly, and you never saw a home with solar panels,” Cahill said. “Now, at least you can see a couple of homes in the flight path.”

For more information, about SolarCity, visit www.solarcity.com.