Biomass study shows growing opposition

The use of sustainably harvested forest biomass to replace oil heat would likely begin to yield benefits in greenhouse gas emissions reduction in as little as five years, but electricity from biomass compares unfavorably with fossil fuels, including coal, according to a Biomass Sustainability and Carbon Policy Study commissioned by the Department of Energy Resources (DOER).

The six month study of issues associated with biomass sustainability and carbon policy conducted by a team of scientists and policy experts led by the Manomet Center for Conservation Sciences shows that the use of biomass for heating and combined heat and power (CHP) facilities would result in a 25 percent reduction in greenhouse gas emissions in 2050 relative to oil, but biomass-fired electricity would result in a 3 percent increase in emissions over coal-fired electricity in 2050. Coal has the highest greenhouse gas emissions per kilowatt-hour of energy produced of any fossil fuel.

Under the Global Warming Solutions Act, Massachusetts is required to reduce greenhouse gas emissions across the economy 80 percent by 2050.

“These findings have broad implications for clean energy and the environment in Massachusetts and beyond,” said Secretary of Energy and Environmental Affairs Ian Bowles. “Biomass energy can be renewable over the long term and it has benefits in independence from imported fossil fuels. But now that we know that electricity from biomass harvested from New England forests is not ‘carbon neutral’ in a timeframe that makes sense given our legal mandate to cut greenhouse gas emissions, we need to re-evaluate our incentives for biomass.”

Biomass technology for generating electricity has qualified for incentives under the Massachusetts Renewable Portfolio Standard (RPS) since the RPS was created in 2002 under the Electricity Restructuring Act of 1997. The RPS provides financial incentives for eligible renewable energy facilities by requiring utility companies and other electricity suppliers to deliver a minimum percentage of RPS-qualified renewable energy to their customers. The Green Communities Act of 2008 accelerated the rate of increase of this percentage (currently 5 percent) from 0.5 to 1 percent annually.

Shortly after the passage of the Global Warming Solutions Act of 2008, an interagency team from the Department of Energy Resources, the Department of Environmental Protection and the Department of Conservation and Recreation began exploring the potential greenhouse gas implications and forest sustainability impacts of biomass incentives. In December 2009, DOER suspended qualification of any new biomass facility for RPS pending the Manomet Center study and development of sustainability criteria addressing biomass supply and greenhouse gas impacts.

“Unlike wind and solar, biomass is a form of renewable energy that emits carbon,” said Department of Energy Resources commissioner Phil Giudice. “With the scientific information provided by the Manomet team, we can begin the process of refining our renewable energy regulations to provide incentives only for biomass energy that truly reduces our greenhouse gas emissions and protects our forests.”

As explained in the Manomet Center report, forest biomass generally emits more greenhouse gases per unit of energy produced than fossil fuels. The report terms these excess emissions, biomass’s “carbon debt.” For biomass electricity, that initial carbon debt is 31 percent compared with electricity from coal. Over time, however, re-growth of the harvested forest removes this carbon from the atmosphere, reducing the carbon debt associated with the initial combustion of biomass for energy. After the point at which the debt is paid off, biomass begins yielding “carbon dividends” in the form of reduced greenhouse gas levels in the atmosphere compared with fossil fuels for producing the same amount of energy.