green energy
8:01 am
Wed April 13, 2011

Wind power battling hydro for transmission lines

When the wind is blowing and the rivers are running high, there's not enough capacity in power lines to handle all the electricity that's generated.

And that could mean that wind-farms have to shutdown for brief periods when there's too much power.

That's the gist of Hal Bernton's story in The Seattle Times, which explains the conflict between the Bonneville Power Adminstration and wind-power producers.  The BPA manages the giant transmission lines that carry surplus power from the northwest to California.

The matter is coming to a head this year because of a huge snowpack in the mountains. When that melts, it fills the rivers where hydroelectric dams sit. BPA officials say shutting down wind farms would be a last resort.

The wind companies, which include Puget Sound Energy, tell Bernton they want compensation if they need to shut down.

"Turbine owners bristle at the BPA proposal, which they say would result in a big financial hit during the blustery spring and early summer months, peak season for wind generation.

"There has been a strong united [wind industry] voice saying 'this is not reasonable,' " says Roby Roberts, a vice president of Horizon Wind Energy, which has built wind farms in Oregon and the Kittitas Valley in Washington."

The cost of any compensation would be passed on to many of the Northwest's public utilities.

The problem is compounded by the need to protect migrating salmon, as Peter Behr reported for ClimateWire and The New York Times in February, when the BPA released its proposal:

BPA says in those circumstances, it would have to curtail wind generation or increase water flows over hydro dam spillways, bypassing dam generators. But excessive flows over spillways can raise nitrogen levels in the water below the dams, violating federal regulations that protect salmon and other fish species.

The bottleneck, so to speak, is the transmission system, which hasn't kept pace with the sudden increase in demand for "green power."

Between two-thirds and three-quarters of the wind generation in the Columbia River Valley is purchased to satisfy California's renewable energy mandate, but congested transmission lines limit the amount of wind power that is actually transmitted out of state.

Power sales to California are also critical to keeping power rates low in the Northwest.