A closed landfill in American Canyon could become Napa County’s biggest solar farm.

A Vallejo-based company has proposed constructing 50,000 solar panels on the top of the 100-acre landfill just northwest of the city.

The solar array could produce up to 6.7 megawatts — about six times the amount of power produced at Napa Valley College’s solar facility.

On Thursday, the Napa-Vallejo Waste Management Authority, which owns the landfill, voted 3-0 to negotiate an agreement with Green Tech Power Group, a Mare Island-based firm that would lease the land from the authority and sell power to PG&E.

Larry Asera, the company president, said Thursday’s agreement will boost his company’s chances to obtain federal stimulus funds set aside for green companies under the American Recovery and Reinvestment Act. The stimulus funds will pay up to 30 percent of the project, which Asera said might cost between $30 million and $50 million in total.

The project could provide up to 75 temporary jobs during construction and up to 30 permanent jobs thereafter.

The landfill is already producing energy in the form of methane gas, which is being captured as it seeps out of the former garbage dump.

Green Tech will prepare studies and plans to build the solar facility on the flat area of the landfill without disturbing the methane gas collecting system., Asera said.

Once built, Green Tech’s solar facility would sell electricity to PG&E and supply power to the Napa-Vallejo Authority.

American Canyon Mayor Leon Garcia and Napa City Councilman Peter Mott serve as board members with the Napa-Vallejo Waste Management Authority. Both met with Asera to discuss his plans for the former dump.

“We think it’s a great opportunity,” Mott said Friday.

On Thursday, Mott and Garcia, along with Tom Bartee, a Vallejo city councilman and the authority’s board chairman, voted to give Asera’s company the exclusive right to negotiate a deal.

Asera, who has built solar panels for the past two decades in the United States and in the Philippines, found American Canyon’s landfill, at the edge of the Napa River and with views of San Pablo Bay, impressive. “What a beautiful site,” he said.

Thursday’s agreement does not guarantee that the authority will approve the project. The proposal will also have to receive the green light from the Napa County Planning Commission because the land is in unincorporated Napa County.

Garcia, who supports opening the service road that loops around the foot of the landfill as a recreational trail, worried about the visual impacts on the city, particularly on houses along Wetlands Edge Road.

“That was a big concern,” he said.

But the solar panels will face south — away from the city — and be placed behind landscaping, Garcia said.

The project’s visual impacts “should not be a problem at all,” he said.

Napa-Vallejo Waste Management Authority General Manager Trent Cave said he could not predict how much money the authority would receive from the new venture. “It’s too early to say how much the authority might realize in addition revenue or savings,” he said.

The Napa-Vallejo Waste Management Authority’s main business is the Devlin Road Transfer Station, which collects waste from Napa, American Canyon, Vallejo and unincorporated Napa County.

The authority also receives revenues in methane gas royalties from the landfill site. A private company that extracts methane gas from the American Canyon’s closed landfill to produce power and sell it to PG&E paid $85,000 in gas royalties over the fiscal year that ended June 30.

The authority has tried — but so far failed — to engineer a system to supply American Canyon’s nearby wastewater treatment plant with methane-based electricity, a project Mott called “disappointing.”