bat and bird impact statements are usually required as part of the
regulatory approval process for wind farms. i'll be interested in your
report and opinion of the experience up there. *the wind farm i saw in
wyoming this summer was visually appealing on the windy plains and hills
in unitas county. *while i have no doubt there are and will be bat
casualties, i doubt it will be of sufficient significance in most of the
areas wind farms will be located.

On a much smaller scale, the Dutch have done some tremendous work in
area of urban wind power. They have a helix type that mounts on
buildings and homes, generates 1.8 to 7.9 KW (depending on model) that
is quieter than a home air conditioner. I don't know anything about
the sonic levels driving bats nuts, but because of the shape, it
appears solid to birds and bats, reducing the chance of bird strike.
There are even areas in South America where they are mounting these on
cell phone towers to power the systems.
http://www.helixwind.com/en/index.php
Frank Reid
(who would dearly love one of these)