I think I'm on my fifth year with my Tarm solo 30, unpressurized storage system. I haven't bought more than a pittance of oil since I started, so I'd say its a success. My wood has ranged a bit in quality, but this year has to be the lowest of the low, but with a low enough moisture content to burn. Last winter I had a couple of large pine trees cut down, and I cut and split the tops and branches, and it added up to quite a bit of wood. I also, on the advice of a forester, cut down a fair bit of poplar last year, but I wasn;t able to get back to it until it was pretty dozey - complete with the purple mushrooms. And this mess along with a small amount of beech mixed in has kept us warm and in hot water so far this year. I know there are some parts of the country where evergreens are all they have and so that's the fuel, but in this part of the country good hardwood rules and folks would be incredulous to hear about heating a house on pine - let alone having smokeless fires to boot!