As metioned before, we invested in a wood burning stove (inserted into our exsisting fireplace) and it has already paid for itself. We had our 1000 gallon tank topped off in the 2nd week of December for $1,316.00 for 575 gallons and still have 40% left. Just time and labor in our firewood. We live on 80 acres so we are supplied for life. I'm happy!!