Biomass electricity generation is being touted as renewable energy with benefits for the state economy, but a comparison between a proposed wood-burning plant in Mancelona and a recently permitted coal-fired plant near Bay City shows that wood-burning plants can emit more of some harmful pollutants.

The 36 megawatt wood-fired power plant proposed by Mancelona Renewable Resources — a subsidiary of the natural gas and oil company Jordan Exploration — would be a much smaller operation than the 830 megawatt Consumers Energy coal plant.

(Creative Commons photo by _Asea via Flickr)

(Creative Commons photo by _Asea via Flickr)

However, because both plants would generate power through combustion, Paul Schleusener, senior permit engineer with the Department of Natural Resources and Environment’s Air Quality Division explained, it is possible to compare their emissions on a pounds per million BTU basis.

The projected emissions of the Mancelona biomass plant and the permitted emissions of the Consemers Energy coal plant are both available through the DNRE.

Particulate emissions for the coal and biomass plants are similar.

“For example, the particulate matter limit for the coal plant permit as issued is .011 lbs per million BTU input,” Schleusener said, “the corresponding number for the Mancelona plant is .012 lbs.”

For PM10 (particulate matter less than ten microns in diameter) the coal plant is expected to release .024lbs. while the wood-burning plant would release .025lbs.

The wood-burning plant would release greater amounts of NOX and VOC, two pollutants that react with sunshine and heat to form smog. The production of those two gasses would be two and five times higher for the wood plant than the coal plant. The Mancelona plant would produce .1lbs. NOX while the coal plant would generate .05. The biomass plant would release 0.017 lbs. of VOCs while the coal plant released 0.0030 lbs.

This comes at a time when the federal government is cracking down on the production of these ozone-producing chemicals. Citing the high public health costs of elevated ground level ozone this month the U.S. Environmental Protection Agency announced a new rule that would reduce the allowable amount of ozone in the air. If put into effect as many as 21 Michigan counties could be required to reduce their levels of ozone-forming pollutants.

Wood burning does produce significantly less acid rain-causing sulfur dioxide (S02) than coal power — .025 lbs vs. .06lbs.

Coal plants have to deal with the sulfur in the coal, said Schleusener, “even with a scrubber it is difficult to get down lower.”

The proposed biomass plant would also produce more carbon monoxide (CO) than the planned coal plant — 0.17 lbs. vs. 0.125 lbs.

Keith Breuker of rural Benzie County said that he is concerned about Traverse City’s plan to build multiple wood burning biomass plants to power the town.

Breuker suffered heart failure in 2004, and though in good health now, he said that he is concerned that particulate pollution is associated with elevated rates of cardiopulmonary disease.

“Air quality monitoring will be needed if we have a plant,” he said outside a crowded public forum on proposed biomass plants in Traverse City.

He added that harvesting and transportation of the wood — which are not reflected in the emissions described by the permit — emit a great deal of CO2.

Everybody is ignoring the public health issue, Breuker said, but “global warming becomes relatively less important if you are dead.”

Despite the air pollution concerns with biomass, environmental groups have been so focused on opposing coal, they seem to be giving less scrutiny to other alternatives.

During a recent conference call about the permit approval for the Consumers Energy coal plant, the Michigan Chapter of the Sierra Club, Natural Resources Defense Council and Citizens Exploring Clean Energy, called for Michigan to turn away from coal and pursue alternatives including biomass.

Michigan Sierra Club director Anne Woiwode acknowledged that her group had not reviewed or commented upon the biomass plant proposed for Mancelona.

Because of their well known environmental impacts coal plants are subject to enhanced scrutiny in Michigan, they must be evaluated by the Michigan Pubic Service Commission and the DNRE for feasibility and prudence. Biomass plants need not meet that criteria, and state law is actively promoting biomass. The 2008 renewable portfolio standard adopted by Michigan names biomass and specifically wood-based power as among the renewable energy sources that will qualify for renewable energy credits. Utilities are required to get ten percent of their energy from such renewable sources by 2015.

There are some signs that health considerations may enter the public debate over new biomass plants, in Traverse city if not in Mancelona.

At a recent public hearing about biomass in Traverse City, Light and Power board member Ralph Soffredini — the former city police chief — emphasized that building new biomass plants was not a done deal and that there would be more study.

“I want to learn more about those particulates,” he said.