When Teanaway Solar Reserve announced last month a plan to build a 75-megawatt solar farm near Seattle, one of its executives said the project would cost "north of $100 million."

Turns out, it will be quite a bit more than that. The company now says the project would cost "more than $300 million" in private investments.

Teanaway is proposing to build the solar farm near the town of Cle Elum, which is about 80 miles southeast of Seattle. The company said Wednesday that it just submitted a permit application to Kittitas County.

The company would only need the county's approval to develop the power plant, which would sit in 400 acres of previously logged forest. Teanaway is leasing the land from American Forest Land. No state or federal permits would be necessary, said Howard Trott, Teanaway's managing director, during a press conference to announce the project in July.

When built, Teanaway would become the largest solar farm in the state. The biggest one now is a 500-kilowatt system belonging to the Puget Sound Energy.

Teanaway hopes that by attracting a solar panel maker to set up a factory nearby it could use panels made in Washington State.

Washington state homeowners are eligible for a more lucrative state incentive to install solar energy systems if they use equipment made in Washington.

During the press conference last month, Trott laid out an ambitious plan to complete the project. He said Teanaway should be able to secure the permits for both the power plant and the factory within six months. The company expects to complete the solar farm in 2011.

Trott declined to discuss how Teanaway would finance the project. It's unclear who else is backing the company besides Trott, who is the only executive listed on the company's website.