-- Two out-of-state renewable energy firms have selected Ford's shuttered Wixom plant for an ambitious $725 million redevelopment project, creating what officials are calling the nation's largest renewable energy park, company officials said Thursday.

The companies, Xtreme Power of Austin, Texas, and Clairvoyant Energy of Santa Barbara, Calif., plan to retool the aging factory, which once built such icons as the Lincoln Town Car and Ford Thunderbird, to manufacture solar panels and utility-scale batteries used for generating renewable power.

Overall, the project could create more than 4,000 new jobs, with production starting in 2011. The project hinges on the companies receiving hundreds of millions of dollars in federal loans to buy the abandoned site from Ford Motor Co.

If approved, the two companies expect to start hiring next year for about 1,000 construction jobs to rehab the site.

Details of the project were revealed Thursday at an event that included Ford Executive Chairman Bill Ford Jr., Gov. Jennifer Granholm and the companies' CEOs.

"Through this effort, we're going to put this plant and our skilled workers of Michigan back to work," said Ford, who spoke amid a backdrop of darkened assembly lines at the plant, which churned out 6.6 million vehicles before its closing in 2007.

The renewable energy companies have been courting state lawmakers to win enough tax breaks to make Michigan their top choice for the project. Senate lawmakers approved a specialized $100 million tax credit Thursday for the project, with a House vote expected next week.

Granholm touted the project as a major win for Michigan, which has been banking on growth in renewable energy to diversify its automotive-heavy economy.

"This is symbolic for Michigan in what we're going to become," Granholm said.

The two companies plan to occupy about half of the 4.7-million-square-foot site and hope to attract complementary businesses, such as wind turbine suppliers.

Clairvoyant plans to make large-scale solar panels at the site, as well as locate the majority of its engineering and development staff in Wixom. It's partnered with Switzerland-based, Oerlikon Solar, a leader in thin-film solar technology, which will also establish its U.S. operations in Wixom.

Xtreme Power builds large-scale batteries for storing power generated from renewable sources, such as wind turbines and solar panels.