Southern California Edison said Monday it has signed a 20-year contract with DCE, an affiliate of Caithness Energy, to provide up to 909 megawatts of wind power.

Once completed, the Caithness Shepherd’s Flat project will be one of the world’s largest fully permitted wind farms, according to SoCal Edison, a division of Rosemead-based Edison International. Financial terms were not disclosed.

The project involves installation of 303 wind turbines across 30 square miles in north-central Oregon in 2011 and 2012. It’s expected to generate 2 billion kilowatt-hours per year of renewable energy. The project requires no additional or upgraded transmission lines, Edison said, which will significantly lessen the time it takes for the power plant to come on line.

Stuart Hemphill, the utility’s vice president for renewable and alternative power, called the contract “a crown jewel in our renewable energy portfolio.”

“The project is attractive to SCE because of its size, near-term delivery and its competitive price,” said Hemphill in a statement.

Caithness Energy, based in New York City, is privately held independent power producer which focuses on renewable geothermal, wind and solar power projects, but also has some coal plants it terms environmentally friendly.