biomass pellets
The way the EU Emission Trading (ETS) has been set up, means that replacement of coal or gas with biomass will lead to higher greenhouse gas emissions, writes Rauli Partanen, freelance author and analyst. And in combination with the renewable energy targets all EU member states have, this is exactly what our policies encourage us to do.
There has been a lively public and academic debate over the actual emissions of bioenergy – to what extent it is carbon-neutral and on what timescale. Supporters argue that even though burning of biomass will lead to carbon emissions, trees that have been cut will grow back, and will eventually sequester the released carbon back from the atmosphere. Opponents argue that even if this is true – and this also depends on the type of biomass involved – it might take decades – and all that time the released carbon dioxide is warming our atmosphere.
When coal is replaced with biomass, the total amount of emissions allowances in the ETS does not change, but on top of that, we also get the emissions from the biomass
Some academics have remarked that bioenergy can only reduce emissions if it is used to replace fossil fuels. Replacing wind, solar, hydro or nuclear energy with bioenergy will always lead to more emissions.
However, what most people fail to understand is that, in the EU, when coal or other fossil fuels in energy production are replaced with biomass, this will also lead to an increase in total emissions. Yes, you read that right: energy production with biomass increases total emissions in Europe – not just when it replaces renewables or nuclear, but also when it replaces coal or gas.
Quite catastrophic
Our climate and energy policies are actually encouraging an increase of emissions. We have adopted a number of individual, seemingly beneficial policies that together create a quite catastrophic situation. Here is how it works.
First, all bioenergy is counted as zero-carbon inside the Emissions Trading System (ETS), which includes all large-scale energy production in Europe (heat and power). But burning of biomass always releases carbon dioxide, which always causes warming. Depending on the type of biomass and the observed timescale, the climate forcing can be smaller or larger. Burning sawdust causes a small impact while chopping up and burning roundwood has a larger impact. In some rare cases the impact might be negative – for example if we burn waste that would otherwise rot and cause methane release (methane is a much more potent greenhouse gas than CO2), but most of the time, it is positive.
Secondly, the ETS has a certain fixed amount of emission rights. If someone does not use their right to emit, it can be sold for someone else to use. So when coal is replaced with biomass, the total amount of emissions allowances in the ETS does not change, but on top of that, we also get the emissions from the biomass (which is counted as zero-carbon).
Until this policy framework is overhauled, the academic discussion on the carbon footprint of bioenergy is just that – academic
The ETS puts a ceiling on emissions from the energy sector, but it also puts a floor underneath them. Whether any member states takes a national political decision to phase out coal has no effect on the total amount of emissions rights on the ETS. Of course it is possible to agree to cut the total amount of emissions at the EU level, and we should, but that is a separate issue. It needs to be noted that cheap and plentiful emissions rights do make it somewhat more likely that we could agree on cutting total emissions.
Third, our current energy and climate policies actively encourage countries to replace coal and gas with biomass. European countries all have targets to increase the share of renewable energy in their energy mix. Over 60% (in 2014) of renewable energy in Europe is bioenergy or waste, which is needed to support the intermittent, non-dispatchable wind and solar. Many countries pay direct and indirect subsidies for bioenergy in order to meet their renewable energy goals.
Academic discussion
And lastly, these subsidies encourage the use of biomass in the power and heating sector, which reduces its availability for other uses, outside the ETS. For example, biomass can be used to replace petroleum-based plastics and other materials, or refined into transportation fuels to replace oil, or used as a feedstock in the chemical industry. In all these applications, biomass would replace fossil fuels.
Until this policy framework is overhauled, the academic discussion on the carbon footprint of bioenergy is just that – academic. It has no relevance in the real world. The current European climate and energy policies are set in a way that ensure all bioenergy used in heat and power production (which fall under the ETS) adds to our total emissions. And so do the various goals to increase renewable energy shares in our energy production, as some of this renewable energy is bound to be biomass.
It is hard to imagine this was the intent of these policies, and it is clear that they need to be fixed as soon as possible.
Editor’s Note
Rauli Partanen (@Kaikenhuippu) is an independent writer and energy analyst who lives in Finland. In addition to his four energy-related books published in Finnish, his internationally published books include The World After Cheap Oil (2014) and Climate Gamble – Is Anti-Nuclear Activism Endangering our Future? (2015).
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The carbon in biofuels was already above the Earth’s surface and part of the carbon cycle. No new carbon is added, unlike when we burn coal, oil or natural gas.
Given that people are unwilling to give up heat and electricity using biofuel is, at least, not increasing our carbon problem by adding more.
Best that we put more emphasis on wind, solar, geothermal, hydro, tidal and other very low carbon footprint energy sources. Use biofuel on a temporary basis, scaling back as we have low carbon replacements.
I agree that using this “fast-cycle” carbon instead of adding fossil carbon to the atmosphere is a good point.
But.
The volume on which we use this biomass-based carbon defines how much of it will be warming the atmosphere at any given time. In this sense, bioenergy is only carbon neutral some 100 years _after_ we stop using it (when it has mostly been taken up by the plants again).
And also, like I say in the piece, currently the amount of fossil carbon released from the EU ETS is set as the amount of emissions credits we can use by a certain date. Using bioenergy will not make this amount any less – and that precisely is the problem. Bioenergy is not replacing any fossil fuels – only adding its own carbon in the atmosphere on top of the fossil carbon we have agreed to release (not to mention the local damages to ecosystems from energy-cropping).
“Bioenergy is not replacing any fossil fuels ”
Where I live it is. We have plants that burn wood waste from timber/lumber operations and turn that energy into electricity. That electricity would otherwise be created by burning fossil fuels.
Additionally, if we didn’t burn the waste in electricity plants we would have to truck the waste out of the area to a landfill and bury it. The carbon released by trucks and excavators (CO2 from fossil fuels) exceeds the wood-CO2 released.
In this case using biofuel is a good thing x 2.
That may not be the case in all biofuel cases. It might be that burning wood pellets from the US in European plants might require the use of large amount of fossil fuel for transportation.
Best we address individual problems in the use of biofuels and not paint all with the same brush.
Bob, I presume you’re American? You’re missing the point of the EU ETS. Within the ETS, there is a fixed amount of emissions that the power and industrial sectors have been allotted. If you have a coal fired power station with a certain amount of credits, and it switches to biomass, it can sell the credits to other generators. That’s how I understand the author at any rate.
Californian. At the moment I am not willing to identify as American. Ask me that question after our next election.
I wasn’t commenting on the EU regs but on the attitude that “biofuels are as bad as fossil fuels”.
That said –
“Some academics have remarked that bioenergy can only reduce emissions if it is used to replace fossil fuels. Replacing wind, solar, hydro or nuclear energy with bioenergy will always lead to more emissions.”
Well, duh. If the EU has written bad regs then it needs to change the regs.
Bad regulation/policies, yes. That was basically the whole point of the article 🙂 (because, as you said: duh. Currently many people think the policies are good)
Bad regulation makes biofuels (in ETS sector) currently basically worse than fossil fuels, as FF’s at least need to be accounted for in the emissions trading system.
Discussion on the good and bad and ugly sides of biofuels is another discussion – and until we fix those policies I mentioned in the article, it remains an academic discussion with little relevance to real life.
I was responding, as I said, to what I viewed as misunderstanding of biofuels, fossil fuels and carbon.
The EU policy appears to need work. But that is separate from whether it is better to burn coal or wood in terms of the amount of carbon in our above-surface carbon overload.
“bioenergy is only carbon neutral some 100 years _after_ we stop using it”
If the biomass we use is regrown as fast as we’re using it then after the first year the bioenergy is carbon neutral.
Imagine a biofuel built on a perennial grass such as switchgrass. Year one we harvest and turn into fuel (ethanol).
Between that harvest and the next the plant regrows, replacing the mass we removed. During growth the plant pulls back CO2 from the atmosphere. Year two we are releasing CO2 that has been recycled.
Do that for 100 years. We have added one year’s worth of plant stored CO2. And have avoided 100 years of fossil fuel CO2.
Wood pellets? The same. Do not consume faster than we regrow. Don’t use slow growing trees that can take decades to grow, use fast growing species which can be harvested and re-harvested on a ~4 year cycle.
“If the biomass we use is regrown as fast as we’re using it then after the first year the bioenergy is carbon neutral.”
Not if we then burn a similar amount again. The important thing is that part of the biomass-carbon will stay in the atmosphere, until we stop burning bioenergy.
Lets say we burn bioenergy after it is harvested. The carbon goes into the atmosphere (causing a climate forcing) for the time it takes to grow again. For perennials this is part of the year (until next growing season finishes), for forest, it depends on the cutting (thinning means the rest of the trees start growing faster, final logging means it will takes a decade or two until any serious carbon sucking starts with the new trees – provided that they are planted like we have to do in Finland by law).
We could use fast growing trees, then again they often dont make sense if one wants to build buildings with them. The average times are what matters, not the fastest crop/tree available, nor the slowest one.
The volume of annual bioenergy use decides the volume of this “recycled” carbon we have in the atmosphere on average each year, which will cause a climate forcing there. This stays so until we stop using bioenergy.
““If the biomass we use is regrown as fast as we’re using it then after the first year the bioenergy is carbon neutral.”
Not if we then burn a similar amount again.”
No, Rauli. All the carbon in the second generation of fuel will have been pulled out of the atmosphere by the second generation plants as they grew.
Plants grow, die, decompose. They take in carbon when they grow, give that carbon back to the atmosphere when they decay.
The first “generation” of biofuel speeds up the decay period, at least for more decay resistant plant material like tree trunks. That is the total addition to the atmospheric carbon cycle.
A first generation speed up.
Gen 1. We harvest a quick growing tree plantation, ship the wood to a converted coal plant, and replant the forest. Or use a species that regenerates from the stump.
Those trees would have died some years later and put their carbon into the atmosphere. We’ve sped up that process.
Gen 2. The carbon released by Gen 1 gets captured by Gen 2 trees and held out of the atmosphere until they are harvested.
Gen 3, 4, … X. Same as Gen 2.
There’s some extra carbon put up by Gen 1 being “decayed” faster, but after that the process is carbon neutral.
Here’s the alternative:
Gen 1. We burn coal.
Gen 2. We burn coal.
Gen 3, 4, …X. We burn coal.
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I’m overlooking the carbon that future generations of plants will sequester in their root systems. Many plants have as much mass below ground as above ground.
If we replanted quick growing trees and let the old set of roots decay below ground we might find biomass to be carbon negative.
—
Leave the building stuff out this. It’s an irrelevant distraction.
Bob, we seems to be misunderstanding each other a bit.
Further, there are two levels on this discussion here: the one is if and at what timescale is biomass carbon neutral (this depends on what kind of biomass is in question) and second, how EU ETS affects this situation.
My article was about the second topic. I suggest we stick to discussing that.
To use the example you gave, if we
– burn coal,
– burn coal,
– burn coal etc,
then that is exactly my point: this coal burning will happen _anyway_ because how the ETS works: the amount of carbon emission rights on the market stay the same when we replace fossil fuels with bioenergy, so someone else will buy those (now cheaper) emissions rights and use them to burn more coal or natural gas as they will be cheaper to burn and more competitive relatively.
And any bio we burn will be added on top of that.
Yes, there are two (or more) discussions underway. That’s what happens when someone puts up text and allows people to comment. Discussions can emerge over which the author has little to no control.
Now as for the EU ETS issue, I’ve said roughly nothing about that. What I’ve responded to is your apparent lack of fully understanding biofuel.
If the ETS is badly designed then it needs to be fixed.
The atmosphere doesn’t care whether the carbon is from a biofuel or fossil fuel. If CO2 has been absorbed into a tree 50 years ago and we burn it now, we will increase the amount of CO2 in the atmosphere right now.
The amount of forests has been decreasing globally (mostly in Africa and South America http://www.earth-policy.org/indicators/C56/forests_2012 ), which means that more forest carbon is released into the atmosphere than is absorbed into new trees.
That’s true, CO2 in the atmosphere is CO2 regardless of the source.
But we need to care about the source of the carbon. We have no effective or affordable way to stuff the carbon we extract when we mine coal or pump oil/gas from below the Earth’s surface. Each spoonful of fossil fuel we extract adds more carbon to our above the surface carbon problem.
Our climate change problem is almost totally driven by the fossil fuels we extract. We need to stop extracting as quickly as we can.
If we’re going to need fuels for some time longer then it makes sense to me to use fuels which don’t add to our above surface carbon load.
Don’t burn 50+ year old trees for fuel. Use waste, crops that can be grown in a single year, or quick growing trees. (Some trees put on amazingly large amount of mass in five years.)
The fixing is done by not letting all that CO2 generated from bioenergy production go up into the air again, either through a CCS type approach or redesigning the plant to produce biochar in the process. I don’t think the situation is as bad as described, but we should really be discussing life cycle analysis numbers in a discussion of this type.
CO2 capture and sequestering is not cheap and uses energy (more fuel ends up being burned).
We have no proven safe way to store very large amounts of CO2 for hundreds of years.
I suspect the smart strategy would be to increase our rates of wind and solar installation. Use biofuels instead of fossil fuels for now. But work at reducing our use of biofuels as rapidly as possible.
If we could get the energy we needed from gas produced in the pyrolysis and put the biochar deeply enough into the soil so that it stayed out of the carbon cycle for many years then we might help our situation. But the economics of a biochar approach are not clear.
I admit the best thing to do is widespread installation of solar and wind, but that is not the whole story! They need to be complemented with something dispatchable, be it batteries or biomass. Batteries are expensive. Burning biomass without some form of CCS seems cheap, but is a detriment rather than a help. CCS is not cheap, but supercritical injection is not the only option for sequestration e.g. cement sequestration. I think we should keep all our options open, but let’s not forget our end goal.
” let’s not forget our end goal”
We are better off taking some stored carbon from an above the surface source and using it than taking carbon stored far below the surface and adding to our above-surface carbon load.
When we use biomass we are recycling carbon that is already above-surface.
Biomass should not be part of our final solution (or no more than a tiny portion). We need to move to all low carbon electricity generation but we’ll only get there in steps. It will take 20+ years to install the wind, solar, geothermal, tidal, etc. generation we need in order to leave fossil fuels behind. If we can lower the rate of fossil fuel extraction now by using biofuels then we make our overall jobs easier.
We have found no way to economically stuff carbon back down in the Earth.
Both of you seem to totally miss the point of the article, which is as much about the EU ETS as about bioenergy. Read the part under the subheading “Quite catastrophic”.
As to biomass being by definition carbon-neutral, things are a bit more complex than that, see e.g. John DeCicco’s article on Energy Post: https://energypost.eu/biofuels-turn-climate-mistake/
Which doesn’t mean that bioenergy is always bad.
An interesting article in which Rauli Partanen makes some valuable points about the anomalies in the ETS. It may not be fit for purpose, but can we at least take some comfort from the fact that although ETS allowances awarded to old coal plants are transferred to other emitters, (not cancelled, which the author would seem to prefer) by no means all of these allowances are actually used. Hence the >2bn surplus of allowances that the Commission is struggling to address.
A better approach would be a straightforward carbon tax on fossil-fired generation, similar to that already imposed in the UK. Admittedly the ETS still applies alongside the tax in the UK At least it does at the moment; let’s see what Brexit brings.
I would take issue with the point in the article which suggests that the “use of biomass in the power and heating sector… reduces its availability for other uses” such as plastics and transport fuels. This implies that the supply of biomass is already under pressure. This is far from true, certainly if you take a medium/long term view. We are no where near “peak biomass”. Bio-plastics and bio-fuels are coming, more slowly than some people had hoped, admittedly, but they are not being held back by an absence of feedstock. When they do come the market, they will have a biomass paying capability far greater than that of biomass electricity generators.
I’m copying this from a comment on another site. There’s no link but it comes from “LCA of pellet burning technologies” by Thomas Willem de Haan.
“Pellets as a heating fuel in domestic appliances can be considered as a low carbon fuel, relative to the alternative fossil fuels. The emissions of a pellet heating system can be as low as 6,04 g CO2/MJ whereas its least polluting fossil counterpart emits 62,8 g CO2/MJ. If the pellets are being transported overseas, the CO2 emission would amount to 27,7 g CO2/MJ. This is still less than half the figure for the lowest fossil heating fuel but the most optimal use of pellets is for application on a local scale.
The most influential parameters are the management of the forest the used wood is taken from and the transportation of the pellets. All the calculations are based on the premise that the harvested wood is regrown. As long as the wood is being harvested in a sustainable way, the low net CO2 emission as determined in this paper can be achieved. It should be emphasized, however, that sustainable harvesting is absolutely necessary to maintain the delicate balance.
Another conclusion to be drawn from this study is that the transportation of sawdust pellets over long distances has considerable impacts. Nevertheless, even transatlantic transported pellets have a lower net CO2 emission than heating with fossil fuels.”
The authour misses an imporant point. Any deployment of renewables will only lead to reduced emissions if the amount of EU ETS permits were reduced and there is no mechanism for it.
Biomass is no different from solar and wind in that respect.
Yeah, (and that includes nuclear), that is another subject that did not get any space in this article (I did not attempt to cover the whole european climate/ETS/energy policy in this one column 🙂 ). The thing is, ETS is in place so that we wont need other policies in the ETS sector. Now we have additional policies that encourage bioenergy, which then adds to emissions total.
And we also have policies that encourage some solutions over other, when ETS was supposed to be market-based solution. All of these policies (RE targets, tariffs, subsidies) only make ETS work worse, meaning our attempts to cut emissions will be more expensive and ineffective.
Forged news. No renewable energy has been installed due to the ETS. Actually no carbon reduction measures has ever happened because of ETS. Biomass is being installed because of the RES directive or because of the EE directive, both with strong sustainability criteria. So the hypothetical case the author denounced never happen and has no risk to happen. Either you have a working policy for the development of biomass with sustainability criteria or you have no development of biomass at all.
The author cites the standpoint that “trees that have been cut will grow back, and will eventually sequester the released carbon back from the atmosphere.” The implied ultimate return of all carbon releases to future terrestrial vegetation does not account for some of the CO2 – anywhere between 27% up to nearly one-third depending on the reference cited – being absorbed beforehand by increasingly acidifying oceans. A forest thus cannot grow back with a full portion of the original carbon. Instead, CO2 from other sources makes up for the relinquishment of particular molecules to ocean absorption. Hypothetically substituting all fossil fuel deployment by biomass combustion would consequently not inhibit aquatic pH declines that are occurring irreversibly in step with increasing carbon dioxide concentrations in the Earth’s atmosphere.
This consideration helps explain why biomass utilization cannot be classified (or mistaken) as carbon-neutral in the manner of solar and wind energy. Maintaining the same level of bioenergy usage while losing more than one-fourth of carbon releases to ocean absorption necessitates introducing an equivalent amount of CO2 from other sources into new growing biomass. It therefore seems erroneous to imagine carbon cycles as contiguous closed loops. Instead, some portions are lost, requiring new segments to be added from alternative sources to restore the entire quantity of carbon.
Particular forestry studies in Germany have suggested that up to two centuries could be needed for plant life to sequester all the carbon emitted at any moment.
A very interesting point Jeffrey, thanks.
There are quite a few of these “indirect effects” that can have both positive and negative effects on the final climate forcing that bioenergy causes. I have to admit that this is the first time I read (and thought) of the ocean acidifying point. I would value much if you had some links to papers / studies on this subject.
And I do admit that I was simplifying in the beginning, where I tried to bring most of the mainstream arguments for and against of expanded bioenergy use into view in a short manner, to give a bit of a background for the actual argument in the article.
In my CCS study published in Sweden, ocean acidification was treated in Section 1.1 ahead of climate change (1.2) because of its cumulative effects, some of which could endure for many thousands of years: http://www.volksmeter.de/Abhandlungen/APC-28-lost-hopes-ccs.pdf
I am not aware of any climate engineering technique that could simultaneously reverse the decline of ocean pH levels. Many proposals might instead become a license to emit even more CO2, which would commensurately aggravate acidification effects.
The following report contains a table with threshold values that relate atmospheric carbon dioxide concentrations to resultant seawater pH levels: http://www.volksmeter.de/Abhandlungen/Michel-EPAPlan&OceanAcidification2014.pdf
This German presentation contains a number of diagrams and illustrations substantiating the progress of acidification and ocean warming: http://www.volksmeter.de/Abhandlungen/Michel-Ozeanversauerung10052013.pdf
” A forest thus cannot grow back with a full portion of the original carbon. ”
Then what is the new biology that allows plants to grow using far less carbon?
I suspect you’ve mislead yourself. Certainly oceans are taking up a lot of the carbon we emit by burning fossil fuels. But plants continually grow, absorbing carbon and then die/decay releasing that carbon back into the atmosphere. What we seem to be observing at the moment is additional plant growth due to increased atmospheric CO2 levels.
“Hypothetically substituting all fossil fuel deployment by biomass combustion would consequently not inhibit aquatic pH declines that are occurring irreversibly in step with increasing carbon dioxide concentrations in the Earth’s atmosphere.”
Plants do not increase the overall amount of carbon in the carbon cycle. That comes from extracting and burning fossil fuels.
Had we been using biofuels rather than fossil fuels since 1880 we wouldn’t be seeing these increased atmospheric and oceanic increases in carbon. The amount of carbon in the carbon cycle would not have increased.
“Particular forestry studies in Germany have suggested that up to two centuries could be needed for plant life to sequester all the carbon emitted at any moment.”
Those are more of the studies which tell us that we cannot grow plants fast enough to suck up the carbon we now release when we burn fossil fuels. We can’t plant our way out of this problem, we have to stop burning fossil fuels.
An original carbon dioxide molecule from tree combustion that is later absorbed by the ocean and converted to carbonic acid will be unavailable for subsequent photosynthesis. The remaining CO2 molecules may be sequestered in a new tree, but additional carbon from other sources such as fossil fuels would be required to enable growth to the original height and girth.
In the early 1800’s, far more biomass was being burned worldwide than coal. Railroad and steamship transportation reversed that relationship after mid-century by distributing coal to distant locations. However, CO2 concentrations in the Earth’s atmosphere had already begun rising a century before, with ocean pH levels descending from the pre-industrial value of 8.179 (Wikipedia). Before coal was widely available, Europe’s forests were being systematically cleared for heating and industrial energy production using wood and charcoal. Many woodlands were later restored after the introduction of coal and lignite.
The oceanographic institute of the University of Kiel recently issued a diagram showing 27% of the CO2 emitted from both biomass and fossil fuel combustion being dissolved in the oceans. Obviously, those carbon molecules can’t reach the trees:
https://www.ndr.de/nachrichten/schleswig-holstein/Meeresatlas-aus-Kiel-soll-alarmieren,meeresatlas100.html
“An original carbon dioxide molecule from tree combustion that is later absorbed by the ocean and converted to carbonic acid will be unavailable for subsequent photosynthesis. The remaining CO2 molecules may be sequestered in a new tree, but additional carbon from other sources such as fossil fuels would be required to enable growth to the original height and girth.”
The reason why we’re seeing an increase in ocean acification is due to excess carbon in the atmosphere.
The new tree will use some of the CO2 in the atmosphere. If we were ever to grow enough trees to start bringing down the level of atmospheric CO2 then the ocean would give some carbon back. *
Human caused atmospheric CO2 levels began to rise hundreds, thousands, of years ago when humans began growing rice. The amount of CO2 did not become significant enough to start problematic climate change until we had a few decades of extensive fossil fuel use behind us.
* And the oceans have stored up about 90% of the extra heat we’ve “created”. As we eventually thin out our greenhouse blanket and let the atmosphere cool off the ocean will give up stored heat. For a long, long time after we might restore the pre-Industrial Revolution atmospheric CO2 levels the plant will continue to be abnormally hot.