A new report from the University of Copenhagen shows that the burning of wood is significantly more climate friendly than coal and slightly more climate friendly than
FACULTY OF SCIENCE – UNIVERSITY OF COPENHAGEN
ENERGY A new report from the University of Copenhagen shows that the burning of wood is significantly more climate friendly than coal and slightly more climate friendly than natural gas over the long run. For the first time, researchers quantified what the conversion of 10 Danish cogeneration plants from coal or natural gas to biomass has meant for their greenhouse gas emissions.
Heat plant
Energy production is responsible for a large part of Danish greenhouse gas emissions. In 2018, more than 20 percent of greenhouse gas emissions were released as a result of heat and electricity production (9.4 out of 48 million tonnes of CO2). Photo: Getty
A conversion to wood biomass (wood chips and pellets) by Danish district heating plants has benefited the climate and is the more climate-friendly option compared to coal and natural gas. These are the findings of a new report from the University of Copenhagen’s Department of Geosciences and Natural Resource Management.
The study is the first retrospective investigation by researchers of what a conversion to wood biomass has meant for greenhouse gas emissions at ten Danish cogeneration plants — and thereby the climate impact of replacing either coal or natural gas in favour of wood biomass.
Among other things, researchers calculated the so-called carbon payback period for each plant, i.e. how long it takes for the conversion to wood biomass to elicit a positive climate effect.
“Our results demonstrate that the transition from coal to wood biomass has had a positive effect on CO2 emissions after an average of six years. When it comes to the transition from natural gas, it has in most cases taken between 9 and 22 years, and in one case 37 years before CO2 emissions were reduced,” says Associate Professor Niclas Scott Bentsen of the Department of Geosciences and Natural Resource Management, who is one of the authors of the report.
Reduction in CO2 emissions
The researchers also looked at the total CO2 emissions from the three energy sources over a 30-year period, which is the life expectancy of a cogeneration plant.
Transitioning from coal to biomass resulted in a 15 to 71 percent reduction in CO2 emissions, while the move away from natural gas resulted in emissions reductions between -4 and 19 percent.
The fact that, in one case, emissions were -4 percent after 30 years as a result of the conversion, is partly due to the fact that, in relation to energy content, burning natural gas emits less CO2 than burning wood, and that this particular plant had notable changes in its product portfolio.
“When such large fluctuations in the figures occur, it is because the payback period and the amount of CO2 emissions saved are significantly affected by the type of fuel, where it comes from and other alternative uses of the wood,” says Associate Professor Niclas Scott Bentsen
Forestry residues are best for the climate
The 10 Danish cogeneration plants collected 32 percent of their wood biomass from Danish forests, while 41 percent was sourced from the Baltic states, seven percent from Russia and Belarus, and seven percent from the United States. The type of wood biomass used and the distance it needed to be transported factored into the carbon budget as well, according to Professor Bentsen.
“For the typical plant that was once coal-fired, but now using wood from around Denmark and only uses forestry residue that cannot be used for other products, the payback period was roughly one year. The 30-year saving was as much as 60%,” explains Niclas Scott Bentsen.
Wood has an enormous potential to displace carbon heavy construction materials such as steel and concrete and is therefore an important aspect of the green transition.
“Our study demonstrates that the extent to which wood is used for construction or other forms of production, where the long lifespan of wood can bind CO2, is even better for the climate than using it as fuel,” says Niclas Scott Bentsen.
FACTS:
The method used in the study includes an analysis of time series from individual plants that includes the pre- and post-conversion period from fossil energy sources to wood biomass. Among other things, the analysis included specific knowledge of the type of fuel used, where the fuel came from and what alternative uses the wood might have had.
Energy production is responsible for a large part of Danish greenhouse gas emissions. In 2018, more than 20 percent of greenhouse gas emissions were released as a result of heat and electricity production (9.4 out of 48 million tonnes of CO2)
Of Denmark’s total energy consumption, 16 percent of energy is generated from the burning of wood biomass. By comparison, 7 percent of energy consumption comes from wind turbines.
To reduce the carbon recovery period and atmospheric CO2 emissions, utilities should focus on using residual biomass (tree branches and crowns from logging or residuals from the wood industry that have no other use), biomass from productive forests, as well as reducing long transport distances.
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The project is funded by Danish Energy and the Danish District Heating Association. The project was followed by a follow-up group consisting of representatives from the Council for Green Conversion, the Danish Society for Nature Conservation, Concito and the Danish Energy Agency. The report is peer reviewed by internationally renowned researchers.
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What about the sulfur and hydrocarbon emissions? Wood is much worse that way than coal…
It isn’t what is said so much as how it is justified.
I’m not sure, but these folks would probably pay top dollar for some ocean front property in Arizona. Can’t be too hard to convince them that California will fall off into the ocean any day now.
RHS: Ah ha; wood floats, another good reason to build with wood. California re-imagined as a floating state. Somebody please tell AOC and Biden.
Cheers,
Glen
I may have missed it but so far, I cannot find any inclusion of the fossil fuel requirements to farm, ship, pelletize and reship wood products, nor the fossil fuel costs to dispose of the ash. Without considering the process costs, the study has no value.
Funny how that always seems to be the case – leaving out production costs…
And thereby lies the problem with wood biomass for fuel. Its a low energy density (by land area), saturated fuel, that must be transported to a central processing station, chipped, and dried before it can be burned. If not used for fuel at that point, it must be further transported to the power station. At least at that stage you aren’t carting excess water around.
Unless you are very close to a large forest area, the economics rapidly dissipate. Not to mention, that I suspect things get very marginal in terms of Energy Return on Energy Invested.
Unless, of course, you have some political reason to subsidize the whole process until the figures work out.
Another study that claims to measure CO2 emissions without actually measuring CO2 emissions.
“Our results demonstrate that the transition from coal to wood biomass has had a positive effect on CO2 emissions after an average of six years. When it comes to the transition from natural gas, it has in most cases taken between 9 and 22 years, and in one case 37 years before CO2 emissions were reduced,” says Associate Professor Niclas Scott Bentsen of the Department of Geosciences and Natural Resource Management, who is one of the authors of the report.”
Wood-Burning is NOT Renewable by a Long Shot
The logging industry claim is “wood burning is renewable” and therefore its combustion CO2 should not be counted (the EPA and IPCC are proponents of this fallacy), whereas, in fact, wood-burning is not renewable at all by a long shot.
I have written extensively on the CO2 released just after clearcutting.
This article has 5 examples of CO2 released, due to clearcutting
http://www.windtaskforce.org/profiles/blogs/co2-emissions-from-logging-clear-cutting-and-burbing
In northern climates, it takes about 35 years for the CO2 to get back to neutral
The initial CO2 release, due to belowground biomass decay, is very high, and the decay is on-going for about 80 to 100 years.
The released CO2 far exceeds any CO2 absorbed by the regrowth on the HARVESTED AREA. That negative condition continues for about 17 years.
But to offset that negative condition, and get back to neutral, regrowth on the HARVESTED AREA needs to take place for another 17 to 18 years
The decay CO2 is entirely independent from 1) combustion CO2, and 2) CO2 other than combustion. See above list and table 1.
– Combustion CO2 of year 1 would have to wait for 35 years to start being absorbed by regrowth on the HARVESTED AREA, which takes about 80 – 100 years.
– Harvesting and other CO2, due to: 1) logging, 2) chipping, 3) transport, 4) in-plant processing, and 5) plant operations other than combustion, etc., is like all other CO2.
The Real World
However, in the real world, loggers would come along, see 40 to 45-y-old trees on the HARVESTED AREA, and cut them down; veni, vidi, vici; i.e., the combustion CO2 absorption process, in effect for about 10 years, is CUT SHORT.
The logging industry continues to claim, without blushing: “Burning wood is renewable”.
Darn those loggers. What a bunch of profiteers. Bad as coal miners. We should halt all logging. If you can go out into the woods and cut trees down, then you can learn to code.
BAN THE BOARD. We can all live in mud huts, or concrete bunkers.
Those lousy loggers make more CO2, I tells ya, and it’s going to fry the Planet big time. It’s Thermageddon acomin’ — the Hotpocalypse. Why won’t anybody think about the children? We’re past the tipping point. Mud huts for everybody! Turn off the power. Huddle in the cold and dark. Grab your ankles. The End is Nigh…
Those darn loggers. Bad industry. Very bad. Ought to be shot…
So you want to shut down the “logging industry, Villy? Because of all the CO2 they make? What about the Petroleum Industry? Or the Steel Industry, the Cement Industry, the Auto Industry, the Agriculture Industry, the Cosmetics Industry, the Chop Suey Industry? Are there any industries you approve of? We’re dying to know, Villy.
You wrote a post? All by yourself? What’s your computer made of? Where did the electricity come from for all your bits and bytes? Cow farts? And to think you did it while huddling in your mud hut!
Do monocropping farmers make too much CO2? All those farm fields with a single crop growing! Must really tick you off. Better write a post about that, after dinner of course. Tax the hell out of them. Make it hurt. That’ll save the planet.
The ash leftover from the combustion of wood can be used as fertilizer. The ash leftover from the combustion of coal is toxic.
Therefore the the ash leftover from the combustion of coal is used for road foundation.
Only if you get that coal ash before it leaks: https://th.bing.com/th/id/OIP.U7HsO980EQwhlkYnfSXJkwHaFj?pid=Api&rs=1
Use of coal ash in cement and concrete improves quality, reduces depletion of natural resources that would have to used instead, reduces energy to manufacture and reduces cost.
The 10 Danish cogeneration plants collected wood biomass from:
32% Danish forests
41% Baltic states
7% Russia and Belarus
7% United States.
13% Unaccounted for
One has to read carefully. It looks like the 68% not produced in Denmark isn’t necessarily from just forestry residue.
Beyond that a pie chart for the U.S. and the world of the forest products industry that includes a slice for wood pellets for power plants would be nice.
Wood smoke has a wonderful aroma when you’re camping but a steady diet of it might not be so great, and just exactly what sort of bag house and electrostatic fly ash collectors for their wood power plants do they have in place? Natural gas doesn’t need all that extra baggage.
The fact that they have to import most of it indicates that this is NOT sustainable. And why are they even doing this if all those Danish wind farms are working so well.
RHS: Ah ha; wood floats, another good reason to build with wood. California re-imagined as a floating state. Somebody please tell AOC and Biden.
Cheers,
Glen
They will bring on a global ecological disaster. Biomass proponents paint pictures of sustainable tree farms, but the reality is it is much cheaper to clearcut virgin forest. Widespread tree farming will only come after cheaper sources are exhausted.
I suppose the silver lining is that with the elimination of the forests there will be less rain, therefore clearer skies to improve the efficiency of the solar panels that will replace the forests, and, there will be less surface friction, improving efficiency of wind power. Now that’s a pretty picture for our grandchildren.
I want to see wood towers with wind generators on top.
Somehow I must have missed the calculations that covered how much renewable land would be needed to roll over the production of wood, for what 35 years, while what you burn today is being replaced. An annual rate of acres needed would be a welcome addition so we could multiply it by 35 to see how many total acres are needed to be harvested.
How about planting a tree and burning coal instead?
“In 2019, biomass provided nearly 5 quadrillion British thermal units (Btu) and about 5% of total primary energy use in the United States.”
Stop it. We’ve been burning biomass for a long time. It’s fine. We have trees forever. It’s Okay to burn them and most of you don’t care about CO2 anyways so if you do, don’t talk about CO2. There’s a lot of bleeping jobs with this for states that only have trees and not coal, oil or natural gas. If a bunch of rednecks want to burn wood, be quiet. You can look and see where our biomass burning plants are located.
Due diligence should have required this calculation PRIOR to converting the power plants, otherwise, what was the justification to convert?
Perhaps the greentards use the ‘build it to make us feel good and damn the consequences’. They can then cherry-pick the good results and ignore the bad ones (much like they do with climate model runs)
I do not “get” this. I worked for 34 years in the forest industry, kraft pulp mill, some as a Power engineer(Boiler/Turbine operator). I come from a forestry family heritage. I have a brother with a forest Resource Management degree. All my life experience screams balderdash over this study and its conclusions.
1/ pellets are not made from forestry waste since real forestry waste (branches and tops) has low fuel value but high levels of important nutrients which need to be returned to the land as fertilizer for the next cycle.
Pellets are made from sawdust and planer shavings with as little bark as possible. These can be used to make ldf, mdf, and hdf (low, medium and high density fiberboard) from sawdust and osb (oriented strandboard) from planer shavings. They are saleable byproducts, not necessarily waste.
2/ Pellet manufacture requires energy investment in sorting, drying and pressing. The actual amount varies depending on the feedstock. This investment does not seem to appear in their accounting.
3/ Up to half of the trees biomass is underground, most of which is left in-situ, rotting and creating methane (though returning nutrients)
Yep – my understanding is that by far the greatest source of methane is the activity of termites etc recycling cellulose back to bio-available nutrients – good old mother nature doing her own thing, no humans required.
The thing that always gets me about the eco freaks is the sheer arrogance of imagining that we control much of anything at all, in the big picture.
1. Wood is renewable but over a span of hundreds of years assuming that the trees are replaced. Fossil fuels are also renewable but the span is longer, millions of years. However fossil fuels are used in the harvest and transport of the wood fuel.
2. There is no real evidence that CO2 has any effect on climate and there is plenty of scientific rationale that the climate sensitivity of CO2 is zero. We do not know what the optimum climate is let alone how to obtain it. But even if we could somehow stop the Earth’s climate from changing, extreme weather events and sea level rise would continue because they are part of the current climate. Saving the climate is rather far fetched.
3. For those who believe in the radiametric greenhouse effect, the primary greenhouse gas is H2O and not CO2. Molecule per molecule, H2O is a stronger H2O absorber than CO2 and on average there is roughly 50 times more H2O in the atmosphere than is CO2. They are doing nothing to reduce H2O emissions. Their slight reduction in CO2 emissions over a very long time span cannot possible have any effect on the overall radiant greenhouse effect if it exists and hence no effect on climate.
4. The AGW conjecture depends upon the existence of a radiant greenhouse effect in the Earth’s atmosphere caused by trace gases with LWIR absorption bands. Such a radiant greenhouse effect has not been observed in a real greenhouse, in the Earth’s atmosphere, or anywhere else in the solar system. The radiant greenhouse effect is nothing but science fiction so hence the AGW conjecture is nothing but science fiction as well. The idea that burning wood will save the Earth’s climate is also science fiction.
5. So by burning wood in Denmark, the Earth’s climate has been saved so no one need worry about climate change any more. The IPCC should hence be disbanded. Thank you Denmark.
What happens when there are no trees to cut down?
If my memory serves me well, wasn’t there a ship building problem in England because there were so few good size trees to cut down for the ships?
Which is one of the reasons why there are so few remnants of ancient forest in England.
You don’t run out of wood by building too many wooden ships.
If you lived on a small island and cut all the trees down to build ships it would take quite a long time to regrow the trees. In the meantime if your island happened to be on a latitude similar to the UK then with no trees to burn, to avoid losing your life due to hypothermia, you would need to use all but one of your ships as firewood. The final one would have to be used for your escape to another place hopefully not already occupied by people building wooden ships, or for that matter making charcoal from cut down trees for iron making. By the way Ragnaar we did lots of the last two things in the UK and just before we ran out of trees we switched to coal for heating, gas making and iron and steel making. It was a close call.
It’s more successful the further away it is from your backyard.