The Biomass Energy Resource Center (BERC) was a partner on the study performed for the Massachusetts Department of Energy Resources, led by the Manomet Center for Conservation Sciences (Manomet) along with other organizations and partners, including the Pinchot Institute for Conservation, the Forest Guild, and consulting forest and resource economists.
BERC’s role included the following:
- Analysis of the technology scenarios and direct carbon emissions for various biomass energy technologies and their fossil fuel equivalents (Chapter 2).
- Analysis of existing public policy at the state and federal levels (Chapter 1).
- Review of the wood supply analysis (Chapter 3), although BERC did not have a role in selecting the methodology used.
The policy actions and recommendations as expressed by the Commonwealth of Massachusetts come entirely from the Commonwealth, not the study. The study was commissioned only to provide information and analysis, not policy recommendations.
At the highest level, the study supports three important conclusions regarding the carbon and sustainable forestry implications of biomass:
- There is a carbon “debt” when biomass is burned for energy, i.e., burning carbon often releases more carbon at the time of combustion than an equivalent amount of fossil fuel and it takes a certain amount of time (specific to both the type of fuel used and the energy technology) to “recover” that debt by re-sequestering that additional carbon. Beyond this point, the continued sequestration of carbon makes the combustion of biomass carbon-beneficial as compared to fossil fuels.
- It is not accurate to simply consider biomass energy “carbon neutral.” The carbon implications and/or benefits of biomass energy depend entirely on several factors, including: where the wood comes from, applied forest management practices, how harvesting and management are distributed over the landscape and over time, and the types of technology used. The study clarifies that, when biomass is sustainably harvested and forest lands are well managed overtime, biomass can be a source of low carbon energy, especially when compared to fossil fuels.
- In using biomass, biomass for heat and cogeneration is the use that is most efficient in reducing greenhouse gas emissions over time compared to fossil fuels. Using biomass for electric generation has a slower payback period, taking longer to show carbon-emission benefits.
- The use of sustainably harvested biomass to replace oil heat would begin to yield benefits in as little as five years, with a 25 percent net benefit over oil by the year 2050. Use of biomass to make electricity takes longer—about 42 years—to begin to create a net dividend compared to coal, but with a positive carbon dividend of 19 percent by the year 2100.
IMPORTANT NOTE: The Associated Press (AP) story by Steve LeBlanc, and subsequent reporting by much of the media, stated: “A new study has found that wood-burning power plants using trees and other ‘biomass’ from New England forests release more greenhouse gases into the atmosphere than coal over time.” This statement is incorrect. The study shows that woody biomass for energy initially has higher CO2 emissions than the fossil fuel equivalent, but, as noted above, over time this carbon “debt” is recovered and becomes a carbon “dividend” in all scenarios analyzed. As noted below, the study also only looked at green woody biomass from forests. It did not look at “other biomass” as suggested by AP, much of which may add no new carbon to the equation (example: forest residues or other wood that would decompose quickly anyway). Finally, the headline associated with the AP report: “Mass. Study: Wood Power Worse Polluter than Coal” is not a conclusion that can be gleaned from this study, and is entirely inaccurate. Pollution includes other emissions of concern present in coal and absent in wood, such as mercury, arsenic, and sulfur dioxides that were not considered in this study.
As with any study of this kind, there are key assumptions that must be understood that affect how the study should be used and interpreted. For the most part, these are explicitly described in the study, but include:
- The study makes no distinction between carbon already in the atmospheric cycle and geologic carbon currently sequestered, and the study does not attempt to address the implications of loading the atmospheric system with new additive carbon from geologically sequestered sources (e.g., fossil fuels).
- The wood supply analysis is an economic and social analysis of how much wood is likely to be available in Massachusetts. It does not provide an assessment of how much wood is actually available on an ecological basis in Massachusetts, which is considerably more.
- Forest harvesting and carbon recovery rates are specific to Massachusetts’ land base and are not applicable elsewhere.
- All harvesting examples assume “business as usual (BAU)” continues, with biomass harvesting added to the BAU case, so there is no analysis about what biomass harvesting alone might look like and no change in harvesting methods for biomass relative to other harvesting. In other words, there was no attempt to optimize the harvesting of biomass and forest management relative to CO2.
- This study addresses CO2 only. Mercury, arsenic, sulfur dioxide, particulates, etc. were not evaluated.
- A key assumption in calculating the relative benefits of burning wood versus fossil fuel is that in the fossil fuel examples, forests must remain forests for the fossil fuel debt to be as low as it is. When burning fossil fuels, those forests are assumed to be there storing carbon on behalf of the fossil fuels.
Below are links to the study and other information:
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