Jan. 26--OLYMPIA -- Environmentalists announced a long-rumored initiative Wednesday that would require large utilities to meet 15 percent of their energy needs with electricity from environmentally friendly power stations by 2020.

If they can collect about 225,000 valid signatures from registered voters by July 7 to get the measure on the ballot and voters approve it in November, it likely would boost the construction of new wind farms.

"This is a doable initiative," said Randy Hardy, a former administrator of the Bonneville Power Administration who is supporting the effort. "Fifteen percent is not an unreasonable goal."

Supporters are planning a campaign that could cost as much as $2 million, depending on what opposition emerges.

The initiative would apply only to utilities with at least 25,000 accounts. Benton PUD has twice that and Franklin PUD may hit the 25,000 threshold this year. Richland Energy Services has somewhere near 20,000 accounts.

Utilities have fought the mandates in the Legislature for years. But private utilities in particular have become aggressive purchasers of wind power.

And the initiative contains two new provisions that are likely to soften opposition among some public utilities. For one, new efficiencies in hydroelectric operations will count toward the 15 percent goal. And the initiative is designed to relieve utilities of any unmet portion of that mandate that would require increasing their overall costs by more than 4 percent.

For now, the long-skeptical Washington PUD Association is neutral.

"I don't know we'll ever be off neutral," said Dave Warren, the organization's Olympia lobbyist. But the group wants to see the actual language of the initiative, which may not be available for another two weeks, before taking an official position.

Sara Patton, director of the green-leaning Northwest Energy Coalition, said she's certain utilities won't see their costs rise as high as the 4 percent cost cap as wind power continues to compete with more traditional forms of generation.

"We believe it will be more cost competitive in the future," she said.

Franklin PUD Manager Jean Ryckman said the hydroelectric and cost- cap provisions are improvements over previous green power mandate proposals introduced in the Legislature, but believes they are "really not necessary. We're starting to move in that direction all the time."

Just this week Franklin PUD acquired two megawatts of capacity from the Nine Canyon Wind Project south of the Tri-Cities and has expressed interest in two other proposed wind farms.