The head of Sonoma County's startup public power agency Tuesday shared a stage for the first time with an official from PG&E as the electricity providers vie for customers ahead of Sonoma Clean Power's May launch.

In a town hall forum in front of a full Congregation Shomrei Torah in Santa Rosa, Geof Syphers, Sonoma Clean Power CEO, hammered the agency's selling points of energy that is cleaner and cheaper than the competition.

"We're not replacing PG&E," he said. "What we do is we buy from cleaner sources of power and then we fill PG&E's wires that they still maintain, and they help get that power to you. So what we're doing is choosing cleaner sources."

Tom Bottorff, PG&E senior vice president, countered that the company has decades of experience reliably providing power to the northern two-thirds of California.

"Geof mentioned that he's the new agency, well I'm the old corporation," he said. "We've been around for a long time ... We will continue to provide all the services that we do today."

For at least the first wave of Sonoma Clean Power customers starting in May, the savings are expected to equal a 2 to 3 percent reduction on the overall electrical bill for businesses and homes. Most of the initial accounts will be commercial customers, with the bulk of residential customers joining next year and in 2016.

"We're not bettering PG&E by a lot, but it's a competitive rate," Syphers said.

The first wave of customers includes 14,000 commercial customers and 6,000 randomly selected residential accounts in the participating jurisdictions, now limited to the cities of Santa Rosa, Sebastopol, Cotati, Sonoma, Windsor and the unincorporated county.

The agency will provide power to an additional 60,000 residential customers in each of the next two years. Altogether, the venture aims to serve about 220,000 accounts, or about 80 percent of PG&E's electricity customers in the county.

Sonoma Clean Power customers will have the option to opt out and return to PG&E for no charge up to two months after joining. After that, customers can opt out for a $5 fee.

Sonoma Clean Power's "CleanStart" package would be made up of sources that are 70 percent carbon-free, with a 33 percent mix coming from sources that qualify as renewable in California.

By comparison, PG&E's carbon-free power amounts to 51 percent of its supply. About 22 percent of the utility's supply will come from state-qualifying renewable sources, including solar, wind, geothermal, biomass and small hydroelectric projects.

Bottorff said PG&E's power mix will match Sonoma Clean Power's 33percent renewables by 2020. "It is going to grow considerably," he said. "We want to see renewables built."

Comparisons between Sonoma Clean Power and PG&E have drawn criticism because some of the agency's renewable portfolio will come from purchaseable energy credits that critics say are a form of "greenwashing."

According to PG&E, less than 1 percent of the company's portfolio comes from such credits.

PG&E is expected to introduce this year its own version of a 100 percent renewable energy portfolio to compete with Sonoma Clean Power's premium "EverGreen" plan, which does not use energy credits and which the agency is promoting for customers willing to pay extra to have a greater impact on greenhouse gas reductions and renewable energy development.

Those future climate-conscious customers, plus activists and business interests, continue to be vocal in pushing for a rapid rollout of side programs and incentives they say would help spur local energy development, create jobs and meet climate goals.

The two energy officials fielded questions from audience members on everything from SmartMeters to how the power providers sort out the clean power from that generated by fossil fuels.

Tuesday's forum marked the first time PG&E directly engaged Sonoma Clean Power and its potential customers.

Sonoma Clean Power is set to become just the second program of its kind to launch in California. The first so-called community-choice aggregation program was formed in Marin County.

Under state law, PG&E is prevented from directly marketing against the ventures, a limit put in place after the utility poured $46million into an unsuccessful 2010 ballot measure that would have limited such public programs, requiring their approval by two-thirds of voters.

You can reach Staff Writer Matt Brown at 521-5206 or matt.brown@pressdemocrat.com.