In recent months, forest biomass (wood burning) power plants have received positive press for their ability to turn waste wood into electic power. However, there’s an on-going debate in the power/environmental community relative to the carbon footprint of conventional biomass power. Power plant proponents claim that these plants release no more carbon than a healthy forest ecosystem over time. Opponents are quick to remind us that this is misleading, in that, forest ecosystems release carbon over many decades, whereas power plants release carbon (as carbon dioxide) in the very near term.
One alternative that has been presented elsewhere here at Cascadia are carbon neutral (or even carbon negative) solutions for power plant projects that employ algal synthesis or “algae farms” to both 1) capture carbon dioxide emissions, and 2) produce oil and feed stocks in return. If you’re interested in reading more about this process, just click “Algae” in the post cloud on right side of this page.
Back to the question of whether or not these conventional biomass power plants are carbon neutral: Below is an excerpt from a recent article in Scientific American which details the thinking in regard to these power plants.
Environmental groups are pressing the EPA to backtrack on its plans to exempt biomass from climate regulations, arguing that such a step would spark an uptick in unregulated carbon emissions
Environmental groups yesterday pressed U.S. EPA to backtrack on its plans to exempt biomass from climate regulations for the next three years, arguing that such a step would prompt more fuel switching to biomass and spark an uptick in unregulated carbon emissions.
The Natural Resources Defense Council and Southern Environmental Law Center (SELC) opposed a proposed rule from EPA that would allow facilities burning woody waste, landfills and ethanol facilities to be exempt from carbon regulations for the next three years.
The proposal would “provide incentives to fuel switch” in order to avoid climate regulations, said Navis Bermudez, deputy legislative director for SELC. The exemption would leave these emitters unregulated, and could result in higher greenhouse gas emissions than using coal, she said at a public hearing on the rule, echoing the sentiments of several other environmental organizations that spoke.
At the heart of the matter is a controversy over carbon accounting and the length of time required to replenish carbon reservoirs.
Past federal regulations have accepted the premise that facilities fueled by woody waste are “carbon-neutral” — merely speeding up the carbon cycle that would naturally occur as plants decompose.
But a study commissioned by Massachusetts last year and conducted by the Manomet Center for Conservation Sciences indicated that burning wood for energy generally results in greater emissions of greenhouse gases per unit of energy than using fossil fuel, based on the efficiency of tapping each resource.
The study rested on a number of caveats — including geographic area, how forestlands are managed and if tree refuse or entire trees were utilized, but its results suggested that moving from coal plants to biomass could actually boost Massachusetts’ carbon emissions in the next several decades (ClimateWire, July 12, 2010).
That finding has been a touchstone for environmentalists concerned that the carbon footprint of such plants is not being addressed.
EPA contends that providing a three-year deferral on the issue will allow it to perform scientific analysis considering to what extent — if at all — these emitters should be included in regulations.
Some in industry worry about uncertainty
The agency will examine the science around biogenic carbon dioxide emissions and develop a rulemaking on how these emissions should be accounted for in future permitting requirements, it said in the proposed rule. The agency is accepting comments on the issue through May 5.
Biomass advocates including the National Alliance of Forest Owners (NAFO) and the Biomass Power Association yesterday hailed EPA’s decision to study the matter and reiterated that climate regulations that kicked into effect in January and affect large stationary sources should not apply to them.
Support for biomass as a renewable energy source would be undermined by considering it a carbon polluter, said Dave Tenny, president of NAFO.
Tenny, whose group originally asked EPA for the exemption, argued that it would be impossible to measure how woody waste would be used if it were not used in biomass facilities; thus any calculations could not fully settle questions of carbon accounting.
Meanwhile, Bob Cleaves, president and CEO of the Biomass Power Association, urged the agency to move faster than the proposed three-year timeline on its final decision to exclude biomass — in order to provide market certainty for potential biomass investors, he said. “Delays will cause regulatory uncertainty and economic harm in areas of the nation that continue to suffer from high unemployment and anemic economic growth,” he said in prepared remarks.
The hearing comes on the heels of an announcement last week from Dominion Virginia Power that it expects to convert three of its Virginia coal-fired plants to run on biomass.
Dominion would have moved forward with its fuel-switching plans regardless of whether EPA granted the three-year delay request, Dominion spokesman Jim Norvelle said in an email. The company expects its biomass plants will be online by 2013 if its plans are approved, and said the facilities would help the company meet Virginia’s voluntary renewable portfolio standard.
Richard Wiles, senior strategist at the Partnership for Policy Integrity, a group focused on applying science to public policy issues, blasted the proposed exemptions yesterday, stating that EPA does not need three years to study this matter. “The state of Massachusetts did a fine job of it in nine months,” he said, referring to the Manomet study. “Waiting three years will have serious real world effects,” he said. “As things stand now, every plant built during that time will be a permanent carbon polluter.”