|Seen on a sign near the
Woodstock (Connecticut) Fair 9/7/98:
$110 a cord
with fossil fuels
|White Oak is one of the best firewoods,
containing about 31 billion joules per cord ( Table
). Therefore one dollar buys you about 280 million joules.
A high-quality woodstove puts about 60% of that, about 170
MJ into the house.
(A cord is an eight-foot long four-foot high stack of four-foot logs, making 128 cubic feet of wood and air space.)
Gasoline contains about 140 million joules per gallon ( Table, fuel oil a bit more, perhaps 150 MJ per gallon. An oil-burning furnace puts about 80% of that, 120 MJ into the house. The fuel oil presently costs about 80 cents per gallon. Therefore, one dollar delivers about 150 MJ into the house, versus 170 MJ from firewood.