One-third of all Americans who work in solar power live in California, according to an annual survey released Tuesday.

And their numbers are growing fast.

The solar industry employed 47,223 Californians last year, up 8 percent from 2012, according to the survey from the Solar Foundation, a research and advocacy group.

Nationwide, the solar industry employed 142,698 people. And while the rate of solar job growth nationwide was faster than in California, nearly hitting 20 percent last year, the Golden State still dominates the business.

"California is, by far, the leader," said Andrea Luecke, the foundation's executive director. "It's not by accident that the solar industry is based there."

Most of California's solar jobs, however, focus on panel installation and financing versus research and development efforts to create new technologies.

Starting more than 10 years ago, California officials made a concerted push to foster the solar industry. They forced the state's utilities to buy more renewable power and offered rebates to homeowners who bolted solar panels to their roofs.

The effort appears to have worked. Most of the country's largest solar companies are based in California, particularly in the Bay Area. The foundation's survey counted 21,653 solar jobs around the bay.