San Francisco is one step closer to adopting the largest municipal solar-incentive program in the United States.

On Tuesday afternoon, the Board of Supervisors voted 7-4 to approve a 10-year program intended to provide between $2 million and $5 million of subsidies for solar installations annually.

If the board passes the legislation in a second reading next week and is signed into law by Mayor Gavin Newsom, as expected, the program will take effect this year.

The incentive would provide $3,000 to $6,000 for residential solar installations, and up to $10,000 for commercial properties.

While San Francisco enjoys a green reputation, solar hasn't been its strong suit. In March, Greentech Media reported that the county ranked last in the Bay Area in kilowatts of solar power per capita, with only 744 out of 195,000 roofs solar-paneled.

Attempts to change the city's ranking haven't been easy.

After months of political finagling, a smaller one-year program – which would have set aside $3 million in rebates offering between $3,000 and $4,000 for residential installations and up to $10,000 for commercial installations – was set to begin in April.

But the program, intended to bring 1.5 megawatts of new solar installations to the city, was put on hold when San Francisco Supervisor Jake McGoldrick, chair of the city board's budget committee, raised concerns about spending so much money (see Solar Setback in San Francisco).

Since then, McGoldrick has been pushing an ordinance that would curb the amount of public funding that could be used to finance solar installation for privately owned residential properties. But the Board rejected McGoldrick’s proposal Tuesday.

Assessor-Recorder Phil Ting said he is “very hopeful” that the 10-year solar-incentive program will pass and added that, if it does, the program could take effect as early as next week.

"This sends a clear signal that we are tired of being part of the fossil-fuel past and we want to move on to the renewable-energy future," he said Tuesday.