The public debate over the relative benefits of wood vs. coal as a source of energy has intensified since the release of the Manomet Center's report on the subject, which was released in June 2010. The latest contribution to the debate comes from Dr. William Strauss of FutureMetrics, who recently released a piece of research he conducted with his colleague Laurenz Schmidt entitled, "A Look at the Details of CO² Emissions from Burning Wood vs. Coal."
In previous posts here (see list at the bottom of this post), I have written extensively on the Manomet Center report and subsequent reports by Strauss and others, who have found fault with the Center's logic. This most recent report, which was peer reviewed by Daniel Parrent, the Biomass and Forest Stewardship Coordinator with the USDA Forest Service, takes a closer look at the Manomet Center's data, and the Center's finding that combusting wood releases 34.6% more CO² into the atmosphere than combusting coal.
The findings in the report include :
- Coal, like wood, does not have a moisture content of zero. Like different types of trees, types of coal have different moisture contents: the moisture content (MC) of anthracite coal is 2.8%-16.3% by weight, the MC of bituminous coal is 2.2%- 15.9%, and the MC of lignite coal is 39% or more.
- On a dry basis (factoring in the energy it takes to evaporate the water in either wood or coal), "coal and wood yield very similar results in terms of CO² produced."
- According to the data outlined in the FutureMetrics report, the Manomet Center's finding that wood at a 45% moisture content produced 34.6% more CO² than coal is off by roughly 25%. "At 45% MC, the combustion of wood yields about 9.0% more CO² per unit of useful energy than an average of the coal grades' outputs."
- "Dried wood at MC's below 20% have the same or less CO² emissions per MMBTU as most coal."
The report also points out that no single assumption about the relative emissions savings of any one project is possible. "Each location will have different outcomes. Coal grades, wood species, moisture contents of both coal and wood, and boiler efficiency will yield unique metrics," says Strauss. All things being equal, however, wood and coal have roughly equivalent CO² emissions.
To read the full report and evaluate the data for yourself, you can download the report by clicking on the report in the right hand column of the FutureMetrics website here.
Other Market Watch reports on this issue include :
Comments
Joe Patton
02-20-2012
Suz-Anne thanks for the correction article. A lot of people reading this would still think that coal is better for the environment. I think it is always important to include that coal is stored underground and has been there for millions of years. When we burn coal we are releasing carbon that has and would be sequestered away from our atmosphere. Trees however are renewable and as trees grow they are Carbon Sponges. As long as we grow more than we cut we will always have a negative carbon footprint by using wood biomass.
Joe Patton
Suz-Anne Kinney
Forest2Market: July 14, 2023
