By the way, since I mentioned natural gas I had to post the following chart...
80% of our electricity in the US is natural gas powered.
Graphs like this make paying $40,000 to place solar panels on your roof seem cheap.
Well, I actually did that. I used to pay $1,000/month here in south Texas for electricity. That's $12,000/year. With power costs rising down here at 15-20%+ a year I will be paid off in less than 3 years and in year 4 will save $20,000 (assuming 20% increases for the next few years).