Policies should address market failures (which are causes) and not distorted outcomes (which are symptoms). Having too few wind turbines is an outcome (symptom) and a government wind-mill policy is not appropriate.
The main market failures:
This one is easy. The proper fix for a low price on carbon emissions is to raise the price. Price carbon. Unfortunately, there is a tendency to try to subsidize everything non-carbon. A bit of this can be excused when carbon pricing is politically impossible, but there is no excuse for pricing carbon with cap-and-trade and then subsidizing your favorite technologies on top of that.
National Policy >