A proposal for what is thought to be the largest solar farm in the nation was disclosed Tuesday by developers who want to construct the complex in eastern Alameda County.

The Mountain House Solar Farm, if built, would produce enough electricity for 250,000 homes and generate 400 megawatts of electricity, executives with Pegasus Energy Partners said.

"We're doing conventional photovoltaic solar, which is tried and true technology," said Michael Clevenger, president of Pleasanton-based Pegasus Energy Partners.

At 400 megawatts, the Mountain House solar complex could produce more electricity than the 370-megawatt plant that Oakland-based BrightSource Energy aims to construct in the Mojave Desert near the Ivanpah settlement.

The Mountain House solar facility would employ photovoltaic solar, a technology that uses panels to convert solar energy directly into electricity. The BrightSource complex uses solar thermal technology that employs a field of mirrors to reflect the sun's rays to a tower where water would be boiled to operate a turbine.

The 2,000-acre East Bay solar farm, planned for open land north of Interstate 580 and west of the Mountain House community in Alameda County, could begin construction during the first few months of 2013.

The first phase of the Mountain House Solar Farm could come on line -- and begin producing electricity -- in 2014.

"This could provide a lot of electricity for a lot of homes," Clevenger said. PG&E, which has substations a few miles from the proposed solar farm, would be among the potential customers for the electricity.

The project also could generate hundreds of jobs as well as electricity.

The solar farm would create 350 to 400 construction jobs over a two- to three-year period. Once built, the energy complex would have 40 to 60 permanent jobs, Clevenger estimated.

Pegasus Energy has applied to the California Independent System Operator for a connection to the statewide electricity grid.

In a few weeks, Pegasus intends to file an application with Alameda County planners for a conditional-use permit for the proposed solar farm, Clevenger said.

"Many of these solar energy projects will succeed, and many will not," said Shayle Kann, an analyst with GTM Research, which tracks the green energy sector. "There are numerous barriers for these projects."

In addition to getting necessary local permits and connection approvals, solar farm developers also must land financing and entice the interest of electric utilities.

"Somebody has to buy the power," Kann said. "Somebody has to be interested in buying the power. Right now, there are more proposed solar projects out there than there are contracts from utilities."

State and federal agencies have attempted to nurture the birth of a robust solar industry in California and around the country.

"The state and federal government are using various initiatives to try to create more green jobs," said Mignon Marks, acting executive director with the California Solar Energy Industries Association.

On Tuesday, Gov. Jerry Brown signed a bill that obliges private utilities to produce 33 percent of their energy from renewable sources by 2020.

"Companies want to undertake more solar development in California," Mark said.

Kann thinks the Mountain House Solar Farm has a decent shot at getting off the ground. "Photovoltaic is proven, and it has been proven that banks are willing to finance these projects."

To bolster the project's financing, Pegasus executives hope to tap into Section 1603 federal cash that provides outright grants rather than tax credits for renewable energy projects.

"It's entirely possible that this project could go forward," Kann said.

Contact George Avalos at 925-977-8477.