A recent decision by the United States Court of Appeals ruled that the U.S. Environmental Protection Agency did not have the authority to put a "biogenic carbon deferral" into place in 2011 that would postpone regulating the carbon emissions from biogenic sources for three years.
The temporary deferral was set to expire in 2014, when EPA is due to release a decision on the future regulations of biomass energy after the results of a 3-year study on carbon emissions associated with bioenergy sources.
The EPA has said it will regulate all carbon emissions under the standards of the Clean Air Act - from burning fossil fuels or biomass alike - if the results of the three-year study do not lead to a different decision.
The court decision does not affect any EPA regulation, nor does it say whether or not the EPA would have the authority under the Clean Air Act to permanently exclude biogenic carbon emissions from the permitting process for a biomass plant.
Dr. Mary Booth is an expert on the environmental impacts of bioenergy, and Director of the Partnership for Policy Integrity, a group that provided testimony for the case. She said because the court's decision has taken away the EPA's deferral on regulating carbon emissions from biogenic sources including biomass, it could have a significant effect on an industry she believes contributes to global warming.
"For the court to tell the EPA that they now do need to count that biogenic CO2 under the Clean Air Act is a big victory...for common sense," said Booth. "It has important implications for how this industry is viewed."
Dr. Booth said a wood-burning biomass plant can produce more carbon dioxide than a coal plant, per megawatt-hour electricity generated.
"The bottom-line is that biomass has been historically treated as a carbon neutral fuel, under the assumption that if you burn a tree it can grow back and resequester an equivalent amount of CO2 as it was released by burning, or that you're burning waste-wood that would decompose and emit CO2 anyway," said Booth. "But this really ignores the time factor and in-fact when you burn biomass for energy you emit 40 to 50 percent more CO2 than even a coal plant, and three-to-four-hundred percent the CO2 of a natural gas plant per the energy generated, per megawatt hour."
In 2012, after a study referred to as the "Manomet Study" was commissioned by the Massachusetts Department of Energy Resources on greenhouse gases emissions from biomass plants, the state removed industrial-sized wood-burning biomass plants with the purpose of power generation from its Renewable Portfolio Standard – a program that incentivizes renewable energy.
The report prepared by the Manomet Center for Conservation Sciences titled Biomass Sustainability and Carbon Policy Study refers to excess carbon dioxide produced in the generation of power as "carbon debt." Over time, after forests reclaim the emitted carbon dioxide and reduce the level of gasses to lower than what was initially produced, it's referred to as "carbon dividends."
The study was specific to Massachusetts and in part concluded that the "carbon debt" from burning woody biomass would initially amount to a higher "carbon debt" than from burning fossil fuels. Over years the gases would be reclaimed from the atmosphere as forests regrow. (Link To Full Report)
The report went on to say that the way wood was harvested for the purposes of biomass power generation also greatly affects the amount of carbon released into the atmosphere.
A press release from Manomet on the report clarified that when a biomass power plant that uses whole trees, the period of "carbon debt", or excess carbon dioxide in the atmosphere could last up to 20 to 30 years before paying "carbon dividends".
A significantly shorter period of "carbon debt' would exist if the trees burned would be used in a thermal application - including the heating of buildings.
The study did not determine the implications of using waste-wood.
Dwayne Berger, Director of Renewable Energy at the Department of Energy Resources, said that the state’s policies encourage biomass burning for high-efficiency applications, but not for electric power generation alone.
"For electricity generation that would be for using it in the form of combined heat and power where you're basically generating electricity but also utilizing the majority of the energy, which comes off as heat, utilizing that heat in some useful way," said Berger.
The revisions to Massachusetts' policies would only grant renewable energy credits to biomass plants that can reduce greenhouse gas emissions by at least 50 percent over the course of 20 years.
While Booth is hoping a decision from the EPA will require biomass plants to use better emission controls to control air pollution, Bob Cleaves, President and CEO of the Maine-based Biomass Power Association, a group that promotes burning biomass for electricity, has other expectations for the EPA's decision on how emissions are to be regulated for biomass.
Cleaves believes that the results of the EPA's scientific study will draw a distinction between burning fossil fuels and burning biomass – and hopes to bring the conversation over biomass back to Massachusetts once a final regulatory process for biogenic carbon emissions is established.
"I commend Massachusetts for asking a question that, frankly, had never really been squarely asked before - which is, 'how are we to account for biogenic emissions?' I think they asked the right question I just think they got the answer wrong, with all due respect, and I think that once EPA completes that process - which is a significant national effort - then we can have another discussion about this," said Cleaves.
NOTE: This article was edited to clarify the results of the case Center for Biological Diversity v. Environmental Protection Agency. A previous version of the article erroneously reported that the court decision would end the EPA's three-year scientific study on carbon emissions from biogenic power sources, including biomass plants. The updated article also provides more information on the results of the Manoment Stud, and also more accurately reflects the positions of the EPA and BPA on the regulation of carbon emissions. The original audio has been removed.