[ToddF]

First of all, how long would it take a natural gas furnace to "break even"? It never will and, since peak gas production is a thing of the past, you cannot even predict what it will cost to run. I'll predict for you: more and more every year...

I installed 120 square feet of solar hot water heat on the front of my house for about $5500 last fall. It heats virtually all of my hot water and I use the extra heat in the cold weater to warm the ground floor of my 2 1/2 story house (it was always cold and I would havd to crank the heat way up to change that).

While solar electricity requires more sacrifice solar hot water works in most places with 5-15 year ROI. Cash flow with good financing is within a couple of years. Read more at greenfreaksolar.com.