Equation

Gathering cutting and chopping. There is a lot of work in getting the firewood to the stove. Some of the wood never makes it to the stack, stacking is just an extra chore, so we carry armfuls straight down to wait outside the window for its turn to enter the mystic portal.
The gas powered chainsaws do take a lot of the burden off of our shoulders with preparing the wood as does the truck. A while ago I began to think about how much fossilised material there is in each drop of gasoline I burn. Fortunately, somebody far more mathematical than me had done some calculations on this. All in gallons and whatnot, so I did have a few little sums to do in order to translate the numbers into a form I could grasp. The figures I found suggest that something in the region of 25 metric tons of prehistoric plant matter is distilled into each litre of gas. I think we burn about ten tons of green wood in a winter with a smattering of dry wood included, so if the equation were to balance out I should be able to heat my home for the winter on about half a litre of gas. That would be a neat trick.
I presume that the reason it doesn't balance is that a lot of the energy has been lost in the refining process. I wonder how much bigger the sun was all those millions of years ago when the plants used the energy from the light it gave them to pull gases from the air and form the bodies that have been liquified for our convenience. No doubt an Internet search could find me an answer to that wonderment too.