I have some figures on efficiency for the Stetson and Mars Hill "wind farms" for the second quarter of 2010: Stetson produced 17 % of its rated capacity; for the same period, Mars Hill produced 28% of its rated capacity. Mars Hill, in Aroostook county, is higher and more exposed than the Stetson I & II site,which is about 50 miles to the south in Washington County.
Both of these industrial wind installations were promoted and built by First Wind. Some information on generators' sales to the grid can be gleaned from the quarterly power sale summaries posted on the Federal Energy Regulation commission's website. FERC refers to Stetson as "Evergreen Wind Power V, LLC", and to Mars Hill as "Evergreen Wind Power LLC".
Stetson, with its 55 turbines, each rated at 1.5 MW, produced 32,000 MWH in April, May, and June of 2010. This is 17.5% of capacity.
Harrison Roper Houlton/Danforth