Puget Sound Energy plans to spend up to $300 million to buy a wind farm near Ellensburg, the first wind-power resource the Bellevue-based utility would own.

PSE says it will announce the deal today for the Wild Horse Wind Power Project in Kittitas County. The project is owned by Zilkha Renewable Energy, a Houston-based company that develops wind farms.

The project is under review by the Washington Energy Facility Site Evaluation Council. If approved, it could be completed in early 2006, said Eric Markell, senior vice president of energy resources at PSE.

Because wind power has become more affordable, utilities find it more attractive. PSE estimates wind energy will be 25 percent cheaper than natural-gas-fired power and 5 percent cheaper than coal-fired power.

Zilkha would be responsible for the permitting process, and PSE would pick up other responsibilities, including some financing and some construction, according to the terms of the deal.

Markell said the company would raise the capital through a combination of debt and equity. He said PSE would not need permission from the Washington Utilities and Transportation Commission to buy the site but would have to ask for a rate increase to recover its costs.

The final price of the wind farm would depend on the size of the project, which is to have 100 to 133 turbines.

The windmills, which are around 200 feet tall with 100-foot-long rotating blades, will be able to generate 150 to 220 megawatts of energy at full capacity.

One megawatt of wind power is enough to supply 330 homes for a year, so Wild Horse could produce enough to supply nearly 73,000 homes a year.

The Wild Horse Project is the first wind project PSE plans to buy, but the utility is looking at others, Markell said.

In May, PSE said it had narrowed its search for new resources from 50 projects to seven, including three wind projects.

Other than Wild Horse, the list includes a Kittitas County wind farm being developed by enXco of Palm Springs, Calif., and a Columbia County wind farm being developed by RES North America of Portland.

PSE estimates that by 2008, it will need power sources that can generate 350 megawatts more power to serve its growing number of users.

In October, it bought a minority stake in a power plant 15 miles from Tacoma that can generate 137 megawatts at full capacity.

Tricia Duryee: 206-464-3283 or tduryee@seattletimes.com

Information in this article, originally published September 21, was corrected September 24. A previous version of this story about Puget Sound Energy buying a proposed Kittitas County wind farm misspelled the name of the farm's developer. Zilkha Renewable Energy of Houston, Texas, is developing the farm.