The BPA, which operates the regional transmission grid and sells power generated by federal dams on the Columbia River system, says the “Environmental Redispatch” measure will only be in place until 30 March 2012.

BPA administrator Steve Wright calls it “an extremely difficult decision” with “no good choice”.

Implementation of the policy brought renewed protest from renewable energy advocates.

“While we are sympathetic to the impact of Mother Nature’s generous snowpack this year, we believe that unilaterally curtailing wind projects with no compensation is an unfair and discriminatory solution to the excess generation issue,” says Rachel Shimshak, executive director of the Renewable Northwest Project.

“It