When it comes to developing renewable energy sources, Washington is among the fastest growing states in the U.S. It ranks No. 3 this year, trailing only North Dakota and Montana, according to the latest figures from the U.S. Department of Energy.

Most of the growth comes from the major wind farms springing up along the Columbia River Gorge, in Kittitas County surrounding Ellensburg and in eastern Washington near the Tri-Cities and Walla Walla.

But the state’s utilities are also looking at tidal, wave, solar, geothermal and biomass as they try to figure out how to meet the requirements of a voter-approved initiative requiring 15 percent of their power be green by 2020.

State agencies are working on developing regulations as the state’s utilities scout out potential renewable energy sources.

Even so, the utilities have a long way to go. And just as they are getting started, the cost of constructing a wind farm has, by some estimates, tripled over the past five years. That is due to everything from a two-year waiting list for the turbines to a shortage of copper and steel because of competition from India and China. The weakening of the dollar overseas hasn’t helped either.

“There is a shortage of just about anything to do with wind power,” said Jeff King, a senior resources analyst with the Northwest Power and Conservation Council. “If the cost of power was the only factor, there would be a rapid loss of interest in wind power. But with the resource portfolio standards and concerns about greenhouse gases, it is still in demand.”

King said there are plans for wind farms capable of producing a total of more than 9,000 megawatts of electricity in the region, enough to power about 900,000 homes. But realistically, King said, only about two-thirds will actually be built.

The Energy Department reported a 34 percent increase in renewable energy sources in Washington state during the first six months of this year. Oregon ranked sixth among all states with nearly a 21 percent increase in renewable resources.

“I’m not surprised,” said Dave Danner, executive director of the Washington state Utilities and Transportation Commission, which regulates the state’s privately owned utilities. “Historically, we’ve been in the forefront. But we have a long ways to go.”

While the commission is writing the regulations implementing I-937 for private utilities, energy policy analysts in the state Department of Community, Trade and Economic Development are working on the rules for the state’s public utilities.

I-937 includes three deadlines. By 2012, 3 percent of the electricity obtained by the state’s larger utilities must come from renewable resources. By 2016, 9 percent of a utility’s energy must be green, and by 2020 it reaches 15 percent.

Only a few of the utilities in Washington meet the 3 percent target, said Liz Klump, a state energy analyst. “I think the utilities will eventually meet the deadlines,” she said.

The state’s public utilities have bristled a bit at new state regulations. Traditionally public utilities have been run locally with little state or federal interference.

“We think it has become more proscriptive than we anticipated,” said Jim Sanders, general manager of the Benton County Public Utility District in central Washington.

Despite the state regulations, Sanders said he didn’t expect his utility to have any problem meeting the deadlines. A group of public utilities is considering banding together to develop renewable resources.

There is one downside to green power – it can be more expensive, Sanders said.

“Eventually it will start showing up in people’s electric bill,” Sanders said. For years the Northwest’s electric rates have been among the cheapest in the nation because of an abundance of low-cost hydropower in the region.

Puget Sound Energy, the state’s largest utility with more than 1 million customers in an area stretching from the Canadian border to Olympia, already exceeds the initiative’s first requirement. Five percent of Puget’s power comes from renewables, mostly two large wind farms, said Kimberly Harris, PSE’s executive vice president and chief resource officer.

PSE is also developing the state’s largest solar project, a pilot project located at one of its wind farms that will help demonstrate whether commercial sized solar projects in the Northwest are feasible.

“Our strategy is to have a diverse portfolio of resources,” Harris said.

Elsewhere, Tacoma Power is considering a number of renewable possibilities, including wind, tidal and a co-generation biomass plant with a local pulp mill that could produce enough electricity to supply 40,000 to 50,000 homes.

“We have not made hard decisions on a renewable energy resource plan,” said Bill Gaines, the utility’s superintendent.

The state’s utilities aren’t the only ones going green. The city of Bellingham is 100 percent green, becoming the largest local government in the country to take such a step.

For now, there are six major wind farms in the state and six small solar projects, according to the Renewable Energy Project, a Portland-based group that tracks renewable developments.

But Rachel Shimshak, the group’s director, said geothermal, biomass and even tidal and wave all show promise.

“There is a generous endowment of renewable resources to be tapped,” she said. “There will need to be investments in things like transmission. But you have to make those investments whether it is wind or coal. Utilities are engaged and participating. You are seeing an evolution.”

Les Blumenthal: 202-383-0008

lblumenthal@mcclatchydc.com