I think energy will need to get more expensive yet, or alternative energy cheaper. There are so many things that I see that I could do to save on energy costs - but they all cost more than the energy, would wear out, probably break, reduce the resale value of the house, etc, etc...
Now, if you built a house from the ground up with excellent insulation, properly designed air exchange units, and as much passive solar heating/cooling as possible (properly sized overhangs, windows in the correct orientation), it might work for you. I just don't think we are there yet.
-ERD50