Personally I find windfarms useful as navigation points
In Scotland at the moment, the number of wind farms has doubled, if not tripled since the last map edition was out. As such, half the wind farms you see aren't on the map thus making them useless, or even add to confusion if you expect a wind farm on one side, and one which isn't on the map is on the other.
When the next map comes out in June I think some people will be shocked at how many wind farms there are now. Ultimately Scotland could become one giant wind farm...