What are the benefits of Middlebury College using biomass?

  • 40% reduction in net emissions of carbon or 12,500 metric tons
  • eliminates 1 million gallons of Number 6 fuel oil
  • transfer to a local, renewable resource
  • education of students and the public about energy use
  • research into new fuel sources, such as willows that local farmers can grow on marginal lands
  • support for locally manufactured green technology
  • stimulation of the local and state economy
  • less dependence on foreign oil
  • used for heating and cooling campus buildings

What is biomass?
Biomass is fuel derived from plants, such as trees, grass, soybeans and corn. Middlebury College uses wood chips in its biomass plant.

How much did the biomass project cost and what is the payback?
The project cost $12 million which includes the construction costs for an 8,000 sq. ft. addition to the existing service building and alterations to other space within the existing building, the biomass gasification system (Chiptech, Inc. of Bristol and Williston, VT) and boiler and control systems, plus design and permitting costs.

At $1.50 a gallon for #6 oil and $37/ton for woodchips the internal rate of return is 8.75% and the payback period is approximately 12 years.  The switch to biomass from #6 fuel oil will save the College around $840,000 per year in fuel costs, with the expected savings increasing by 3% per year. The project will also pump $800,000 annually into the local economy through the purchase of woodchips. The expected life of the plant is 25 to 30 years.

Doesn’t burning wood cause pollution?
The biomass plant uses a highly efficient gasification process. Wood chips are super-heated in an oxygen deprived environment, where they smolder creating gasses that are ignited to heat the boiler, which produces steam. The filters in the biomass facility are rated to remove 99.7 % of the particulates from the exhaust. Most of what you can see coming out of the smoke stack is actually steam. Overall the emissions produced by the biomass plant are not greater than those that result from Number 6 fuel oil. In fact, burning wood will produce significantly less emission of sulfur compounds, which contribute to acid rain.

What happens to the ash?

Ash is collected and used by a local fertilizer company in their products.

Is biomass gasification carbon neutral?
Biomass gasification is carbon neutral because it releases the same amount of CO2 absorbed by growing plants. When burned as a fuel source, there is no net increase in the amount of CO2 in the atmoshere. This is different from burning fossil fuels, which causes a net increase of CO2 in the atmosphere.

How many wood chips will Middlebury’s biomass plant use?
The biomass gasification plant will use approximately 20,000 tons of wood chips annually, which during peak heating will mean 2-3 truckloads of chips will be delivered daily. A Biomass Fuel Assessment was prepared by Vermont Family Forests to determine the availablity of such a supply in the local area.

Where do the wood chips come from and are they sustainably harvested?
The College works with Cousineau Forest Products, broker to source wood chips within a 75-mile radius. Middlebury is working with the broker to develop a wood chip procurement policy to ensure the sustainability of logging operations.

Does Middlebury College have plans to produce its own biomass?
Middlebury, in collaboration with the SUNY School of Forestry, is 2-1/2 years into a promising 4-year research project on College lands to test fast-growing willow shrubs as a locally produced fuel source. Local farmers could grow willows on their marginal land and chip it without needing costly new equipment. The result: more income for local farmers, and less fuel used in shipping Middlebury’s fuel stock.

What percent of the college’s carbon footprint will the biomass plant reduce?
The college projects that its carbon emissions will be reduced by about 12,500 tons, which represent an estimated 40 percent of the college’s 2006 carbon emissions.

How is the 12,500 tons of CO2 calculated?
The 12,500 tons of carbon dioxide is calculated by estimating the amount of Number 6 fuel oil that will not be burned if the college were to use 20,000 tons of woodchips per year. That amount equates to about 1.078 million gallons. There are 0.01167 tons of CO2 equivalents per gallon of Number 6 fuel oil. The amount of CO2 equivalents in 1,078,000 gallons of burned fuel oil equates to 12,500 tons.

Is biomass now the only fuel source used for heating and cooling the campus?
No. Middlebury will still burn fuel oil in addition to wood chips to provide adequate heating and cooling to the campus.

What else is sustainable about the biomass plant?
The biomass plant uses the excess pressure from the steam to co-generate approximately 3-5 million kilowatt-hours of electricity per year. Also, the heat from the exhaust is used to preheat water going into the boiler.

What is the College’s long-term goal for reducing its carbon emissions?
In May 2007 the Middlebury College board of trustees approved a plan to become a carbon neutral institution by 2016. The press release on this commitment is available here.

Does the College have a plan for reducing the rest of their carbon footprint?
Yes. In 2008, a team of people from across campus developed an implementation plan entitled “Winning the Race Together: Achieving Carbon Neutrality by 2016”. This plan emphasizes the need for institutional commitments coupled with participation from individuals and departments.  Based on these recommendations, the College is pursuing pilot projects related to solar thermal, wind, and increased efficiency for campus buildings.

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