And the really neat part about it is that, if you're environmentally-conscious, you can sign up with Green Mountain Energy and pay a premium for your electicity -- because Green Mountain (who is also a generator) produces their electricity via environmentally-friendly windmills scattered all over West Texas.
But wait! It gets better! Green Mountain Energy is also a retailer. And they buy their electricity on the same market everybody else does. Meanwhile, their windmills just feed their juice into the grid -- not direct to their retail customers.
This inventive arrangement makes everybody happy. Green Mountain's oh-so-green customers get to pay a premium for (they think) environmentally-friendly windmill generated electricity. Green Mountain's owners (the Wyly Brothers) collect a premium price on generic electricity, while selling their windmill juice direct to the grid at wholesale prices. And the rest of us don't have to pay for crazy inefficient environmental schemes.
Are you sure the windmills sell their electricity to the grid at wholesale prices? I would assume that they would get a premium rate since customers pay a premium to opt-in to wind/solar electricity.