Windpower does look promising, tho the stocks are not performing yet it seems.  25 yrs ago, I think a watt of solar cost 20 time what coal could produce it.  a yr ago, it was less than twice coal price.  Just think of the tipping point when it is equal or less!  Solar sure did sell off.  I bought SPWR in the spring for 50, again in the summer for 77, sold in the fall for about 130, it is in the 60-75 range again!  ASTI has great tech, but a startup, it has made me good $.  Many co's are  looking to make roofing and siding with solar panels incorporated, big potential.