Like 28 other states across the country, Massachusetts has enacted a Renewable Portfolio Standard (RPS) to steadily increase the percentage of the state's electric power that is derived from renewable sources, in large part as a means to gradually decrease greenhouse gas emissions from the use of fossil fuels. In addition to wind and solar power projects, state government in Massachusetts has invested more than $1 million to facilitate the development of four proposed wood biomass power plants as part of the effort to reach its goal of generating 15 percent of the state's electricity from renewable sources by 2020. In late 2009, after growing concern over proposals to construct three (30-50 MW) biomass power plants in the Western half of the state, the Massachusetts Department of Energy Resources (DOER) suspended all applications for biomass-based electricity generation from being a compliance option under state's renewable portfolio standard (RPS).

Last year, the Massachusetts Executive Office of Energy and Environmental Affairs, issued an order for a comprehensive study of greenhouse gas emissions from wood biomass power plants, to determine if they can be operated consistent with the sustainable management of the state's forests and the goal for greenhouse gas emissions reductions. With the release of this study, the Massachusetts Department of Energy Resources (DOER) may issue new regulations for biomass power facilities. Revisions in forest management policies are also plausible.

Led by the Massachusetts-based Manomet Center for Conservation Sciences, the team includes the Pinchot Institute, the Biomass Energy Resource Center, Forest Guild, and several independent forest ecologists and resource economists. A four-person advisory panel was established, consisting of nationally-recognized experts who have assisted the core research team in the design of the project and the interpretation and presentation of findings.

The Biomass Sustainability and Carbon Policy Study offers a comprehensive and cutting-edge analysis of the environmental, social, and economic implications of biomass energy. Although the study was initiated to help facilitate informed policy decisions within Massachusetts, it offers a framework of analysis that has relevance to all regions of the country.

Key Questions and Findings of the Massachusetts Study:

1. How much wood is available from forests to support biomass energy development in Massachusetts?
   • At present, landowners receive between $1 and $2 per green ton of biomass. An estimated 325,000 to 500,000 green tons per year could be economically sourced from intrastate and interstate lands at this price level.
   • At $20 per green ton, an estimated 1.3 to 1.7 million tons of biomass per year could be economically sourced from intrastate and interstate sources.
   • Biomass prices are relatively low and inelastic because of the competitive dynamics of the energy sector and the transportation distances required to provide adequate feedstock for large-scale biomass electricity facilities.
   • Smaller-scale, more efficient biomass utilization technologies (i.e. thermal and combined heat and power (CHP)) require much less feedstock than large-scale electricity facilities, allowing for increased biomass market price elasticity.
2. What are the potential ecological impacts of increased biomass harvests in Massachusetts, and what if any policies are needed to ensure that these harvests are ecologically sustainable?
   • The potential ecological impacts have a high degree of variability on a stand-to-stand basis.
   • It is unclear how landowners and forest managers will alter harvest regimes in response to developing biomass markets.
   • The adoption of sustainability guidelines for biomass harvest is advisable to mitigate potential negative ecological impacts.
   • A detailed literature review of current scientific research and of existing domestic and international biomass policy was provided to aid Massachusetts policy makers in the establishment of their own sustainability guidelines. Explicit recommendations for regional sustainability standards were also provided.
3. What are the atmospheric greenhouse gas implications of shifting energy production from fossil fuel sources to forest biomass?
   • Because of its comparatively lower energy density, wood combustion emits more GHGs per unit of energy than fossil fuels, resulting in an initial "carbon debt."
   • Because forests sequester carbon through regeneration, the carbon debt of biomass combustion may be "paid off" over time and eventually yield a "carbon dividend" when biomass combustion results in lower net GHG emissions than fossil fuels.
   • The amount of time required and feasibility of attaining a "debt-then-dividend" scenario is depends on several key variables: the bioenergy technology employed, the fossil fuel technology replaced, the fossil fuel replaced, the forest management characteristics of biomass harvest areas, and the forest management characteristics during the time period following biomass harvests and biomass combustion. The study revealed that the interconnected nature of these factors has significant impacts on the GHG mitigation benefits.
   • Debt-to-dividend times ranged from as little as 5 years to over 30 years, and in some scenarios, full carbon neutrality was not attained until much later.
4. Implications of the Massachusetts Study
   • This analysis is perhaps one of the most comprehensive and critical studies of sustainable biomass energy to date and centers on key issues with high relevance for policymakers. The carbon debt-then-dividend model developed for this study offers a unique and critical framework to compare the status quo of forest management and energy production with potential biomass scenarios. While the calculated end-values are specific to Massachusetts, the framework of the study can be applied to any region.
   • Renewable energy portfolio mandates may conflict with GHG emission reduction goals, therefore an accurate GHG lifecycle accounting framework is important to inform policy and energy project proposals.
   • Current policies favor biomass electricity generation, which is typically less efficient than biomass thermal and CHP technologies. Biomass thermal and CHP technologies require less biomass than electricity only technologies and proved to be more favorable from a carbon debt-to-dividend perspective in the Massachusetts analysis.
   • Electricity and thermal technologies have different price elasticity profiles which have significant effect on feedstock availability. In addition thermal projects are typically of small-scale and draw from localized feedstock sources.
   • The "carbon-neutrality" of biomass energy is a much more complex issue than typically perceived. The GHG lifecycle accounting framework used in this study can be applied in any region of the country, although variations in forest type, rates of tree growth and mortality, forest ecosystem disturbance intervals, business-as-usual forest management circumstances, and a variety of other region-specific factors would likely alter results region to region. The degree to which a particular bioenergy system can realistically be described as "carbon-neutral" depends on the interaction of these forest system variables with a number of energy system variables.
   • Determining the sustainability of forest-based biomass energy is complex and requires evaluating a number of interlocked social, economic, and environmental values that people expect from forests. As interest and investment in forest-based biomass energy continues to increase, scientific analyses, such as those presented in the Massachusetts Biomass Sustainability and Carbon Policy Study provide a critical service to policy makers.

For several years, the Pinchot Institute for Conservation has been highly involved in the exploration of the sustainability concerns of biomass energy to support science-based decision-making in the development of biomass energy policy. For additional information on the Institute's bioenergy programs visit: www.pinchot.org/bioenergy

Conservation is the foresighted utilization, preservation and/or renewal of forests, waters, lands and minerals, for the greatest good of the greatest number for the longest time.

-Gifford Pinchot