# Wood Chip electricity generation



## sugarbush (Jul 15, 2007)

It is a popular electricity generation fuel in the north east and I haven't seen any chip burners anywhere else in the country. We have all this talk on solar, wind, nuclear, "clean coal" (sorry, I have to quote that one) gulf stream power generation....Why is nobody talking about chip burners??

Last year the city of lexington gave away over 200 k tons of wood chips that the city collects from the curb and taking down trees around town.... This is only a city of 65,000 people. If we can generate that many chips in one year imagine what all cities are generating combined. Also god only knows how many millions of tons of slash is left on the forest floor after a harvest in this country every year...This could be a valuable step towards energy independance and for the most part it is being over looked.

http://www.cleantech.com/news/968/laidlaw-to-build-50-mw-woodchip-power-p


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## EDDIE BUCK (Jul 17, 2005)

Yes,around here the pulp mills and big logging crews are suppling chips to a plant producing electricity. They leave no tops or large stumps in the woods. After the chips are burned, farmers can get the ash for their land.


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## MELOC (Sep 26, 2005)

i like the idea of using such a renewable source, but i think it would be easy for folks to get carried away with it. we need to leave something in the forest to break down and replentish the soil. if we don't, we will eventually turn the forests into rocky, treeless hills. we need to think long term about forest management. i have no issues with using waste that would normally be tossed in a landfill or burned.


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## Argono (Apr 8, 2008)

Northwest Missouri State University burned wood chips for heat, and I believe, electricity, as well in the late 80s to early 90s. Haven't been back in a while so I don't know if they still do, but it was a selling point 20 years ago.


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## EDDIE BUCK (Jul 17, 2005)

MELOC said:


> i like the idea of using such a renewable source, but i think it would be easy for folks to get carried away with it. we need to leave something in the forest to break down and replentish the soil. if we don't, we will eventually turn the forests into rocky, treeless hills. we need to think long term about forest management. i have no issues with using waste that would normally be tossed in a landfill or burned.


 Most if not all logged forest around here is replanted as soon as possible after logging.


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## MELOC (Sep 26, 2005)

you are missing the point. how much can you farm land without replentishing it? maybe it would take a long time to deplete the forests, but they do benefit from decaying vegetation. if you strip them bare and leave nothing, eventually they will become barren. if we become addicted to scrub brush harvesting, and it has been proposed, eventually we will be left with barren hills of rock.

don't get me wrong...i am a fan of renewable energy sources, but we musn't get carried away with it.


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## sugarbush (Jul 15, 2007)

I think most small cities and towns generate enough bio-waste that they could probably at least offset a good chunk of their energy needs. Their are even towns in the Pacific Northwest that are taking all the solid waste from surounding towns and generating electricity with it.

Meloc: You have a good point about the depletion of our forests. We know that is possible because we have done it in the past. We also know that they do hrow back and we have all kinds of managment methods now days that should not be overlooked. Here in KY our electricity comes from coal fired plants. The coal comes out of the eastern mountians through mountian top removal mining practices..... What is worse; having to re-plant and fertilize a forest floor or removing the entire mountian so the trees do not even grow there anymore?

I will say that the mountian top removal has made some great habitat for elk. Had to make a drastic change in topography, but the elk are here.....


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## stanb999 (Jan 30, 2005)

MELOC said:


> you are missing the point. how much can you farm land without replentishing it? maybe it would take a long time to deplete the forests, but they do benefit from decaying vegetation. if you strip them bare and leave nothing, eventually they will become barren. if we become addicted to scrub brush harvesting, and it has been proposed, eventually we will be left with barren hills of rock.
> 
> don't get me wrong...i am a fan of renewable energy sources, but we musn't get carried away with it.


I think it also depends on what is being used.
For instance here in our state they are using the strippens to grow fast growth trees. They are then being harvested for electrical energy. They improve/provide soil and can be harvested. 

One has to look past the virgin forest argument. We have almost none. We do however have a lot of areas that would benefit from such industries.


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## MELOC (Sep 26, 2005)

it has nothing to do with "virgin forests". i didn't even get into other arguments like erosion and such. my point is that as a suppliment, it has merit, but we cannot rely on that resource and get carried away. i support the use of woodchips/slash etc. for power generation, i just don't want it to get out of hand.

as far as trusting studies by foresters and forestry schools and the forestry industry...you need to consider the source. they will find in favor of themselves time and again because it supports their industry. the example that comes to mind is the debate over logging vs. virgin forests for the sake of fire prevention. one side claims that too much fuel leads to fire potential. the other side claims that destroying the canopy results in the fuel that will always be present in the understory will dry out incredibly when the canopy is removed and create fire prone areas. just like bankers running the banking industry, foresters will tend to decide such debatable issues on the side favoring business. they need to keep themselves employed.

MELOC <======= not anti-logging by any stretch of the imagination, but likes to keep an open mind.


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## stanb999 (Jan 30, 2005)

MELOC said:


> it has nothing to do with "virgin forests". i didn't even get into other arguments like erosion and such. my point is that as a suppliment, it has merit, but we cannot rely on that resource and get carried away. i support the use of woodchips/slash etc. for power generation, i just don't want it to get out of hand.
> 
> as far as trusting studies by foresters and forestry schools and the forestry industry...you need to consider the source. they will find in favor of themselves time and again because it supports their industry. the example that comes to mind is the debate over logging vs. virgin forests for the sake of fire prevention. one side claims that too much fuel leads to fire potential. the other side claims that destroying the canopy results in the fuel that will always be present in the understory will dry out incredibly when the canopy is removed and create fire prone areas. just like bankers running the banking industry, foresters will tend to decide such debatable issues on the side favoring business. they need to keep themselves employed.
> 
> MELOC <======= not anti-logging by any stretch of the imagination, but likes to keep an open mind.


I figure we are agreeing more than disagreeing. 

I just wish that agroforestry would be boosted . So we could use the marginal lands for a "productive" use rather than cutting potentially valuable timber lands for slash. 

True forest land has more "value" than the single timber one. On this I think we both can agree.


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## sugarbush (Jul 15, 2007)

Virgin forests are not even part of any forestry debate. We have no virgin forests....we do have some virgin trees, but no forests....

Yes the forestry programs are going to advocate the best research in forestry managment, The research of one program will differ from another. The program at the University of Kentucky has a 14000 acre research forest and they practice clearcutting on... They cut everything because they believe that if you leave the small undesirable trees that the future trees in that area will be undesirable for lumber production. They drop everything and run it all over to compact it into the soil to prevent erosion. I believe that if we had bio-chip power plants in this area they would be hauling at least a percentage of that slash out, but we don't, so they don't...


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## fishhead (Jul 19, 2006)

Meloc is right. We cannot harvest trees without replacing the nutrients those trees removed from the soil. Eventually the soil will run out of nutrients just like a farm field that gets harvested but not replenished and tree and other plant growth will slow. If they would return the ash to the forest that would help.


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## fishhead (Jul 19, 2006)

Back to the topic at hand. There are lots of tree service businesses around here and I believe they look for places to dump the chips. What does a house sized chip furnace cost?

It would take some kind of solar kiln drier for the chips but that could be simple and relatively cheap.


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## fishhead (Jul 19, 2006)

http://www.sredmond.com/vthr_index.htm

I guess I was wrong. Chips don't need to be dried to work well.


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## sugarbush (Jul 15, 2007)

fishhead said:


> What does a house sized chip furnace cost?


I am not sure there are any... They are a steam generator so building our own would probably be frowned on.


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## fishhead (Jul 19, 2006)

I got off on a tangent and was thinking of home heating instead of electric generation. It sounds like it might be doable and like I said we've got lots of tree service companies in the area. After a storm they pull huge box trailers full of chips past my house.

I know when I used to heat with wood I would sweep up the bark and throw it in the stove. It made one of the hottest fires and lasted quite a while.


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## sugarbush (Jul 15, 2007)

fishhead said:


> I got off on a tangent and was* thinking of home heating* instead of electric generation.


This same idea as been spinning in my head for a while. The tree truck around here have signs on them that say free wood chips.... They have to pay to dump them at the landfill and the garden centers can only handle so much..

I have been thinking of a drum type stove that had a auger feed system... I would get the fire going good with dry wood and then feed woodchips in on timed intervals.


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## fishhead (Jul 19, 2006)

That article said that augers had problems with chips but I suppose you could always oversize.

I just skimmed the article but it seems to be a batch furnace with the heat stored in water and then pumped into the house just like an outdoor furnace. I've never understood why outdoor furnaces don't do that. My friends was the stinkiest smolder pot I've ever seen and it gobbled up wood like crazy. It makes much more sense to me to make so you can let'r rip and store the heat in a large volume of insulated water.


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## sugarbush (Jul 15, 2007)

I got two loads of chips dumped in my yard today.... I am going to experiment this winter...If it don't work out I will have plenty of mulch in the spring


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## Al. Countryboy (Oct 2, 2004)

Some years we have had 30 loads of chips from tree surgeons that clean limbs around power lines and dump on our land which I use as mulch. I also have burned it from time to time in our wood burning heater which actually does pretty good. The only problem I have using these chips as fuel is that these chips when piled up green over a few inches go into a heat and break down very fast and hold alot of moisture inside. They could be spread out a few inches thick during sunny dry weather and stored dry under a shed, but I never had enough room to store enough dry chips to last very long. I also have to turn the draft up on the heater because the chips lay close together so that they just smolder without producting alot of heat. I am sure that a pellet tpye wood burner would do much better than mine does with these chips and someone has probably figured out ways that solves the problems that I had using these chips. Guess I will for the time being be happy with the results from using these chips around our flower and vegetables.


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## coup (Feb 28, 2007)

i say that leaves do most of the maintaining in the forest system.


MELOC said:


> it has nothing to do with "virgin forests". i didn't even get into other arguments like erosion and such. my point is that as a suppliment, it has merit, but we cannot rely on that resource and get carried away. i support the use of woodchips/slash etc. for power generation, i just don't want it to get out of hand.
> 
> as far as trusting studies by foresters and forestry schools and the forestry industry...you need to consider the source. they will find in favor of themselves time and again because it supports their industry. the example that comes to mind is the debate over logging vs. virgin forests for the sake of fire prevention. one side claims that too much fuel leads to fire potential. the other side claims that destroying the canopy results in the fuel that will always be present in the understory will dry out incredibly when the canopy is removed and create fire prone areas. just like bankers running the banking industry, foresters will tend to decide such debatable issues on the side favoring business. they need to keep themselves employed.
> 
> MELOC <======= not anti-logging by any stretch of the imagination, but likes to keep an open mind.


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## fishhead (Jul 19, 2006)

Al. Countryboy said:


> Some years we have had 30 loads of chips from tree surgeons that clean limbs around power lines and dump on our land which I use as mulch. I also have burned it from time to time in our wood burning heater which actually does pretty good. The only problem I have using these chips as fuel is that these chips when piled up green over a few inches go into a heat and break down very fast and hold alot of moisture inside. They could be spread out a few inches thick during sunny dry weather and stored dry under a shed, but I never had enough room to store enough dry chips to last very long. I also have to turn the draft up on the heater because the chips lay close together so that they just smolder without producting alot of heat. I am sure that a pellet tpye wood burner would do much better than mine does with these chips and someone has probably figured out ways that solves the problems that I had using these chips. Guess I will for the time being be happy with the results from using these chips around our flower and vegetables.


I would think a person could set up a simple plastic greenhouse shelter over the chip pile to pull off the moisture. Spread it out a few inches deep to dry and then repile and cover it until winter. The chips should burn as well as the bark I used to sweep up each spring to burn. That burned really hot for a surprisingly long time.


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## SouthernLiving (Sep 16, 2008)

Many of the paper mills in our area use wood chips to generate their own electricity and steam. Efficient conversion takes much more than just dumping the chips into a burner and letting her rip. There are chemical treatments, cooking processes, lime kilns, ect, ect...don't let the fact that the primary fuel is wood lead you to believe its a "green" alternative.

That being said, there is obviously a financial advantage to doing so on a large scale considering how many large paper corporations like Weyerhaeuser and IP are producing their own power with wood.


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## sugarbush (Jul 15, 2007)

Bio-mass boilers that are consumer size are available and quite popular in Europe. They are not approved for use in the US yet. There are people who have built their own and do generate steam power with them as well as heat houses. The chips don't need to be dried or even kept dry. The boilers work like a blast furnace. Another fuel is used to get the internal temp up so the chips will combust and then that fuel is shut off and the woodchips fed in.


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## fishhead (Jul 19, 2006)

A person could probably rig up a way to use the hot exhaust gas to dry the chips too. That might be a way to capture some of the particulates so they could be fed back into the combustion chamber for a more complete burn.


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## bloogrssgrl (Jan 20, 2008)

Apologizing in advance for a thread drift.

fishhead, regarding the house sized chip furnaces, they aren't really out there as far as the US market goes just yet. DH and I have been looking into these for a few years now and it came down to importing one (for many $$$), having one custom built (again, for many $$$), or building one on our own. We weren't necessarily looking to generate electricity with it so we didn't have to be concerned about steam. We were mainly looking to tie into a hydronic heating system. Anyway, you might want to check out the design of the Goliath furnace by New Horizon for some ideas if you want to tinker on your own.

DH has now started tinkering with a rocket stove design. Not sure how or if this will work out for us. Here is a cool link to check out. http://drtv.dancingrabbit.org/2008/04/30/rocket-stoves-video-superefficient-wood-fired-heaters/


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