The traditional 3-blade wind turbines there have been shown to be very lethal to raptors, including the federally protected golden eagle, because they fly over the hills hunting ground squirrels and don't see the turbine blades spinning until it is too late. In the Altamont Pass, 4700 birds are killed annually. This makes this wind farm an ideal spot to test a new wind turbine design to reduce bird deaths.
The current wind turbines at Altamont Pass. "Wind energy converter5" by P0lyglut - English Wikipedia, original upload 1 December 2004 by P0lyglut. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Wind_energy_converter5.jpg#mediaviewer/File:Wind_energy_converter5.jpg
The new shrouded wind turbines. Photo by Ogin, Inc.