Over 4,500 solar panels, slightly tilted, are now attached to 48 hanger roof tops at the San Rafael Airport.
Paul Brunner is with Synapse Electric, the company that built and installed the panels.
"Actually, it's an ideal location; you have existing roofs, so you are not building new structures," Brunner said.
This installation will create enough energy to power more than 700 homes, even more in the summer. It is the biggest renewable energy project in Marin County.
Bob Herbst manages the airport, which has been running on solar power since 2004. He says the project is in line with the county's energy self-sufficiency plans.
"Clean up our environment and reduce and hopefully one day end our dependency on foreign oil," Herbst said.
The airport will now sell the power to a non-profit called Marin Clean Energy. Fifty percent of its power is renewable.
"A good way of thinking about renewable power is that it comes from a source that is not going to run out -- sunlight, wind..." Marin Clean Energy spokesperson Dawn Weisz said.
Marin Clean Energy was set up by the county as a green utility company competing with PG&E. As a result about 80,000 Marin County residents were automatically switched over, without any kind of input.
Marin Clean Energy says the decision was not made by them, but by the California Public Utilities Commission.
"Their intention there was to make sure that the program could be viable because it's very difficult for a new market entrant to enter into a monopoly territory and be able to gain enough customers," Weisz said.
Customers had until July 1 to opt out. According to Marin Clean Energy, only 20 percent of residents did.
San Rafael resident Jason Fong was one of them.
"I have been so used to PG&E my whole life and now this other company is coming in," he said. "What's going to happen?"
The new agency will buy the power but PG&E will continue to distribute it.
Marin Clean Energy says because it is a non-profit, people's electricity bill will be slightly lower and any revenue that comes in goes back into the company, another way, they say, to ensure rates are kept low.