New study: burning trees for power worse for climate than burning coal
Posted June 11, 2010 in Moving Beyond Oil, Solving Global Warming
A study commissioned by MA Department of Energy Resources and released today reaches the conclusion that burning trees to make electricity is worse for the climate than burning coal at least through 2050. In fact, the study by the Manomet Center for Conservation Science finds that between the release of carbon when trees are burned and the slow reabsorption as the trees regrow, that this source of biopower would increase emissions by 3% compared to coal power over 40 years.
This will come as a shocker to some, but it really shouldn't. Wood contains less energy per pound of carbon, and forests — especially in the northeast — grow slowly. So when we burn a tree, we're releasing more carbon and getting less energy than we would if we burned coal and then re-absorbing that carbon very slowly.
In other words, not only is biopower from trees not carbon neutral, it's worse for global warming than the worst fossil fuel. This myth of carbon neutrality has been a big part of the biomass industry's lobbying. It came up from surprising and unfortunate corners in yesterday's Senate vote to protect EPA's ability protect our air quality. Hopefully this report will put an end to the silly idea.
But in busting the myth, we have to be careful that we not ignore some of the reports conclusions or overstate them. For instance, this AP story ignores the conclusion that using trees for combined heat and power can provide a 25% reduction in GHG emission compared to oil. Furthermore the report doesn't look at carefully sourced wastes and residues or biomass grown on fallow or degraded lands.
The right lesson for policy makers to take from this study is that we have to carefully account for the carbon associated with bioenergy. I've written about the importance of getting this accounting right before and just recently 90 scientists called on Congress to get it right in climate legislation and energy policy. Efficient uses of the right sources of biomass can provide an important supply of low carbon energy, but you don't get that if you pretend that it's all the same let alone all carbon neutral.
Comments are closed for this post.
Comments
KEITH SCHNEIDER — Jun 11 2010 09:25 PM
The Massachusetts wood biomass study said yesterday that the greenhouse gas-reducing benefits of replacing coal and natural gas with wood biomass for electrical generation are lower than previously thought.
But the study by the Manomet Center for Conservation Science also found that specific wood biomass technologies, particularly state-of-the art wood biomass plants that generate combined heat and power, produce less than half of the CO2 emissions generated by a coal-fired power plant and 19 percent less than a plant fueled by natural gas.
See a full account here: http://modeshift.org/
Peter Crownfield — Jun 12 2010 06:43 AM
I haven't read the full report, Does it consider only the emissions at the power plant? How about the emissions, environmental, public health, and moral implications of extracting coal & natural gas through mountaintop removal, fracking, and other enormously damaging extraction methods?
pkc
Russ Finley — Jun 13 2010 06:13 PM
Kieth,
You are comparing apples to oranges; a state of the art power plant utilizing CHP and wood to a conventional one using coal.
That just means that a state of the art coal power plant that utilizes combined heat and power would still produce less carbon than a wood power plant.
R Brooke Coleman — Jun 15 2010 12:25 PM
Nathanael,
The environmental movement's response to this report, including yours, is incredibly frustrating. No matter what side you are on with regard to biomass, please be precise about what the report says and does not say.
The report looked at one subset of the biomass world -- what it calls "biomass from natural forests." It does not address residuals. It does not address waste. It does not address non-forest biomass. It treats all forest products as primary commodities, which is news to the biomass industry. In California, for example, something like 10-15% of biomass resource comes from in-forest.
You say people need to be careful not to overstate, then you say, "not only is biopower from trees not carbon neutral, it's worse for global warming than the worst fossil fuel." Not true in general, not what the report says, and incredibly imprecise in terms of analysis.
Let's drill down on what this report actually says. This post just feeds the spin cycle.
Tom Blakeslee — Jun 19 2010 10:51 PM
I wasn't surprised when the denialist newspapers ran the alarmist headline that misstated the findings to apparently recommend coal burning over biomass based on looking at a worse-case situation which is hardly ever done. As a former contributor to NRDC I am shocked and disgusted to see you running that same headline. Yes we shouldn't chop down forests to keep the lights on but lying headlines like yours only help the "Clean Coal" industry to keep their evil business alive.
Nathanael Greene — Jun 20 2010 11:37 AM
Thanks, Brooke and Tom, for highlighting a point I obviously should have stated in a big clear way: the conclusions from the Manomet and EWG report emphatically are not that we should continue to burn coal. Saying something is worse than evil in no excuse for being evil. But the fact that some will willfully misinterpret these studies to support burning coal and that there are sources of biomass and approaches to using that are positively good for the climate, does drive home what I take to be your point on the need to be clearer that coal in not the answer. (Sadly, a whole blog is probably needed to drive this point home.)
And I think we would all agree that not only must we slash our dependence on coal but that the good news is that we have the technologies to do so between efficiency, other renewables and careful use of sustainable bioenergy.
The one point I would challenge you and others on is the question of how extreme the idea of burning whole trees for power is. While I don't agree with all the assumptions in the EWG report, the point it makes about the scale of demand for biomass that will be driven by the biomass loophole and the RES must not be ignored.
Brooke Coleman — Jun 24 2010 11:04 AM
It goes farther than that. The studies authors themselves have released statements running away from the headlines MA DOER and NRDC created. As to your last point, the study treats something that is complicated very simplistically. Harvesting forests (in whatever form) is constrained by realities. And one of them is "whole trees" are going to fetch far higher prices as timber than power. So there is this overlap with whole trees, waste and residuals that is muddied by simplistic conclusions that whole trees are just commodities. But this is a distraction -- the real issue is fear mongering at NRDC.
John — Jun 24 2010 11:55 AM
Nathanael,
You are quite right that the carbon emissions associated with biomass can no longer be ignored. But the Manomet study is being badly misconstrued and misapplied, on this blog, too. The findings cannot be globally or nationally applied. They are strictly limited to Massachussets, as Manomet asserted three days ago: http://www.manomet.org/sites/manomet.org/files/Manomet%20Statement%20062110b.pdf
On the other hand, the Manomet study *methodologies* CAN be applied elsewhere. And they should be replicated, far and wide, so that we can discern which kinds of biomass energy are truly climate friendly, in different regions.
More on the importance of location, here: http://bit.ly/SACEonManomet
What do you think of the proposals put forward to track biomass carbon based on forest-inventory data? If, despite biomass utilization, a state or region has net growth of forested acres, do you think we could thusly fix the accounting error?
With appropriate estimation of the carbon in standing timber, sampling and modeling of soil carbon, and subtracting for emissions from harvest and transport, I am seeing a system that might be practical.
Other than this, I have yet to hear of a bioenergy-carbon-accounting system that would not be overly burdensome. Given the emerging scientific consensus that there are some forms of bioenergy that are clearly climate-friendly (http://bit.ly/biomass_consensus, and CHP and thermal), and the urgent need to displace coal in the short term, we've got to get this right.
Thanks for blogging.
Meg Sheehan — Jun 24 2010 08:56 PM
Nathanael and all,
This discussion is all too Orwellian. The real question is, why are we subsidizing burning anything and calling it "clean energy"? It's purely absurd. With all due respect to the Manomet scientists, the state asked them to answer the wrong question: the question isn't "how many trees, residues or otherwise, do we have to burn and how much CO2 does it emit" but "why burn trees at all?"
Here in Massachusetts, like the rest of the nation, we already get 50% of our "clean" energy from biomass incinerators that burn whole trees, residues and anything else that looks like "wood." We don't need any more of this primitive technology. The five new proposed plants will add only 1% more electricity to our power supply, but increase greenhouse gas emissions 11%. Where is the sense in that? Who cares whether they are burning residues, mill waste or whole trees (like at McNiel). It's just plain dumb.
This tempest in a teapot about the "real meaning" of the Manomet study is a red herring. The real question is how burning trees under the rubric of increasing our "energy independence" is turning the whole notion of a "clean energy economy" on its head. These plants are being assailed by the medical community from coast to coast and cancer causing, asthma-triggering nightmares.
Our forests have been assaulted, slashed, burned, diced and sliced for 300 years. It's time to leave them alone and implement conservation and efficiency to save that 1% the the five new plants will produce, then look for truly innovative sources of power. Here in the land of the Pilgrims, we really don't need to incinerate our forests again, even if its for "combined heat and power." Enough already.
The Biomass Accountability Project, Inc.
Cambridge MA