How Much Wood is Need to Run a Wood-Burning Truck?


| 8/22/2012 11:04:00 PM


Tags: wood gas, Wayne Keith, Kentucky, Chris Saenz,

So... How much wood could a wood-truck chuck if a wood-truck could chuck wood? Let's find out.

Wood chunks 

Quoting Wayne Keith:

"Most people want to know, how much wood does it burn? In controlled studies we did at Auburn University, my Dodge Dakota got about 1.25 miles per pound of dry wood. It turns out that the truck is 37% more efficient on woodgas than gasoline, so it works out to 16 lbs per gallon equivalent."

"Sometimes people jokingly ask how many miles I get per log. When I tell them that my truck goes 5,200 miles per cord they stop laughing. Firewood in most rural areas sells for around $50 per cord. So if I were to buy wood, I could travel for less than a penny per mile. However I have never had to buy firewood or cut a live tree to feed my trucks. I get all the scrap wood I can use from my homemade sawmill. Wood gas is a great fit for me since I have scrap wood laying right in my way."

(Read more about Wayne's wood gas trucks in this feature article: Wood Gas Wizard! - MOTHER EARTH NEWS)

chris saenz
8/28/2012 1:21:13 PM

Check out this Mother Earth article on growing 5-10 cords of hybrid poplar per acre! http://www.motherearthnews.com/renewable-energy/hybrid-poplars-zmaz80jazraw.aspx Granted that's half the BTUs of hardwoods. On a weight basis, they claim to produce 36 dry tons per acre every 4 years. At 9 tons/acre annually, a 3 acre woodlot could keep 5 drivers supplied with fuel. Now the ethanol farmland could fuel up to 55 million drivers, versus the 16 million it does now.


chris saenz
8/28/2012 12:40:01 PM

Hi T brandt, I know it's conservative, that's the idea. I can't find any studies showing average yields per acre in different management systems. National forests won't be managed for yields, but for maximum forest health. Also don't forget the energy used to harvest the wood and process it. I feel confident there's at least a cord per acre left over. For the farms I think the number is really conservative, I bet a determined farmer could have yields of 2-3 cords per acre easily, far surpassing the fuel output of the cornfields. Should be less work overall and soil enhanced instead of depleted.


chromie1
8/28/2012 12:35:38 PM

Hi T brandt, I know it's conservative, that's the idea. I can't find any studies showing average yields per acre in different management systems. National forests won't be managed for yields, but for maximum forest health. Also don't forget the energy used to harvest the wood and process it. I feel confident there's at least a cord per acre left over. For the farms I think the number is really conservative, I bet a determined farmer could have yields of 2-3 cords per acre easily, far surpassing the fuel output of the cornfields. Should be less work overall and soil enhanced instead of depleted.


t brandt
8/26/2012 9:47:32 PM

I love the way you've worked thru the math, but you're being really conservative in the estimates of yield per acre. A cord is 128 cu ft, and a 2 ft diameter tree, 30 feet high is 378 cu ft ( I know, a trunk is tapered, but we're not even counting the branches and small scrap). Let's say it takes 48 yrs for a tree to grow to that size, so harvest one, plant one. Spaced at a sparse 30 ft between trees, there' be 48 per acre. You'd never notice one being taken from an acre each year. When the last "old growth tree is harvested, the first of the new plantings is ready for harvest. Very sustainable....Even at $200/cord, you're still getting 25 miles per dollar of fuel.


mara lambert
8/25/2012 4:38:57 PM

$59 a cord? Where? Here in rural western Oregon, softwood goes for $170 to over $200 a cord and hard wood $180 to over $225. Green wood is cheaper in the spring, but it has to dry over the summer to be useable in fall and winter.The National Forests have been logged out and the wood is coming from private lands.





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