CLARIFICATION: An earlier version of this story incorrectly stated that the program hasn't fared well. After the story was published, Mayor Gavin Newsom's office said the incentive program actually has led to an increase insolarinstallations. Newsom's remark was meant to indicate high expectations, not an unsuccessful program, his office explained.

San Francisco's much-heralded solar incentive program hasn't fared as well as expected, Mayor Gavin Newsom said Tuesday.

"It's going all right, not as well as we hoped," said Newsom, who summoned reporters to announce new steps the city is making to boost solar power installations.

Newsom declined to explain why the incentive program is not meeting expectations. The city plans to release information about the program's progress Wednesday.

To help improve the performance, the mayor is launching a new measure to encourage more businesses to install solar power.

San Francisco will soon send letters to up to 1,600 businesses to offer them free energy-efficiency audits and solar-installation estimates in hopes of doubling the city's solar power generation by next year, Newsom said.

The offer is an expansion of the city's groundbreaking solar-incentive program enacted in July, which provides rebates of $3,000 to $6,000 for residential solar installations and up to $10,000 for commercial installations (see San Francisco Solar Incentive Becomes Official, San Francisco Offers Solar Subsidies, San Francisco Solar Subsidy Steps Closer and Solar Setback in San Francisco).

Newsom said his office is mulling a citywide solar financing program that could share similar features as the one passed by the city of Berkeley, Calif. earlier this month. The Berkeley program allows homeowners and businesses to take out loans to install solar panels and pay them back through property taxes (See Berkeley to Launch Solar Financing).

"We like it – we don't love it," said Newsom about the Berkeley program.

Wade Crowfoot, the mayor's director of the climate protection initiative, noted that Berkeley had to create a special tax district for its solar program, something that wouldn't be easy to in San Francisco. But San Francisco wants to launch a pilot program that would provide loans to residents and businesses to install systems to generate solar and other types of renewable power, Crowfoot added.

In the meantime, the city will focus on encouraging businesses to install more solar power systems.

The idea behind the so-called "Mayor's Solar Founders' Circle" is to use mapping data to identify businesses that are "perfect candidates for solar" and offer them the free audits and estimates through a $200,000 U.S. Department of Energy Grant, Newsom said.

"We're now sending a letter to 1,600 businesses and knocking on everyone's doors," Newsom said. "We'll do all the work, is the idea."

Installing solar panels on the roofs of all 1,600 businesses could boost the city's solar power capacity from about 5 megawatts today to more than 170 megawatts, he said.

Of course, the city couldn't afford to pay incentives to all of the identified businesses at once, given that it has set aside only between $2 million and $5 million per year for its 10-year solar incentive program, Newsom said.

Still, Newsom hopes the new program could entice enough businesses to double the city's current solar generation capacity to 10 megawatts by September 2009.

At the press event, Newsom also discussed the city's plan to install electrical car charging stations. His office released a list of 19 companies that have submitted plans to set up the charging-station network San Francisco after asking for proposals in July (see San Francisco to Boost Small Wind).

The list of responders included well-known names such as Better Place and Coulomb Technologies, as well as other companies, nonprofit groups and individuals.

While Newsom wouldn't offer any specifics on the individual proposals, he did say that the city intended to pick companies to ask for more detailed proposals by October 15. The companies would be responsible for financing the charging-station projects.

"However, all of them require the city to be participants" in various ways, such as offering city light poles or parking meters to be used as charging stations for plug-in hybrid or electric vehicles, he said.

Few plug-in hybrid or electric cars are commercially available, but consumers can expect to see more of them in showrooms in the next two years. Toyota and General Motors have announced plans to bring plug-in hybrid cars to the market by 2010, and startup manufacturers such as Tesla Motors are building electric cars today.