we use oil, which was very expensive this past summer. luckily we only needed a bit over 100 gals. to top off our tank. since installing a woodstove, we've only needed the furnace to run maybe twice in the early mornings. wood is free, some cost for gas to run the logsplitter, and a lot of physical work....but we are loving it. it's warmer than we've ever been. however, it works well for us because our house is small, open floor plan (like an A-frame interior), and the stove is central. (I'm sure most homes it would only heat the room it was in) had the pricey cost of the woodstove this year, but soon as oil climbs again (and it will) it will pay for itself in no time. I like the look of the woodstove, too. glass doors so we still have the fire to enjoy. most important to us is we never have to worry about being warm if the power goes out.