I’d be a bit more conservative with some of those numbers. I don’t actually know how much they let the logs dry; it could be they’re usually shipped green to avoid damage to them at the site of felling. Furthermore, 1,000km might be a more typical distance for wood to be shipped in Canada, since most of the forest is way up north, far from population centers. We’ve still got comfortably an order of magnitude, though.
Cutting the logs down to size probably takes negligible energy by comparison, and is going to be electricity-based at this point anyway. I’d also have used carbon mass rather than energy, but that’s actually going to work in our favour, because petroleum gets a lot of it’s energy from the hydrogen within it as well, while wood is effectively carbon+water for plant biology reasons.
Oh yeah, it has a lot of holes! Despite the effort I put in, I should have called it what it is: back of the envelope analysis. The only reason I did it was to satisfy my curiosity regarding the initial statement, then felt compelled to share it. :)
I doubt they let the logs dry at all, but the only caloric content I could find for logs assumed air-dried to 20%. I don’t know enough to consider other methodologies like carbon content, etc.
My 100 km was intended as a rate of energy consumption, not an actual hauling distance, but I didn’t make that clear.
“They did the math”. Thanks!
I’d be a bit more conservative with some of those numbers. I don’t actually know how much they let the logs dry; it could be they’re usually shipped green to avoid damage to them at the site of felling. Furthermore, 1,000km might be a more typical distance for wood to be shipped in Canada, since most of the forest is way up north, far from population centers. We’ve still got comfortably an order of magnitude, though.
Cutting the logs down to size probably takes negligible energy by comparison, and is going to be electricity-based at this point anyway. I’d also have used carbon mass rather than energy, but that’s actually going to work in our favour, because petroleum gets a lot of it’s energy from the hydrogen within it as well, while wood is effectively carbon+water for plant biology reasons.
Oh yeah, it has a lot of holes! Despite the effort I put in, I should have called it what it is: back of the envelope analysis. The only reason I did it was to satisfy my curiosity regarding the initial statement, then felt compelled to share it. :)
I doubt they let the logs dry at all, but the only caloric content I could find for logs assumed air-dried to 20%. I don’t know enough to consider other methodologies like carbon content, etc.
My 100 km was intended as a rate of energy consumption, not an actual hauling distance, but I didn’t make that clear.