Green Mountain’s Green Energy
A student-led study and proposal to replace the oil heating plant with a biomass plant help the college make big gains in curbing greenhouse gas emissions.
By Karla Hignite
Green Mountain College in Poultney, Vermont, has been a leader in energy conservation since the 1990s. Significant efficiency measures continue today with window replacements in student dorms, lighting retrofits, and a thermal audit to identify additional weatherization needs of the college's 25 buildings, some of which are more than 100 years old. But Green Mountain scored its biggest gain in curbing greenhouse gas emissions with the induction of its biomass plant on Earth Day 2010.
The idea originated from a student-led study and the students' proposal in 2006 to replace the college's 60-year-old fuel oil heating plant with a combined heat and power plant that would burn locally sourced woodchips. Of primary concern: Emissions resulting from the use of "industrial strength" No. 6 fuel oil that alone accounted for more than 60 percent of the college's carbon footprint, says Joseph Manning, vice president of finance and administration. "At the time, we were at work on some major energy efficiency projects, so the proposal was temporarily set aside-though not for long," notes Manning.
In 2007, the college hired Biomass Energy Resource Center, a Vermont-based consulting firm, to validate the student proposal and conduct a wood supply study. The firm's findings gave college leaders comfort, says Manning. Students were on target regarding the carbon-reducing benefits of a biomass plant, and the proposed fuel source was in plentiful supply. The consultant's study identified 1.3 million acres of timberland within a 60-minute drive of the college that could provide well beyond the required 5,000 tons of woodchips needed by the college to offset the 260,000 gallons of fuel oil it used annually.
Another plus: The campus already had the underground network of pipes needed to move the heat to buildings throughout the campus. The fact that biomass was not a risky new technology gave other leaders confidence that what had already proven beneficial for more than 30 public school systems in Vermont—and for peer institutions Middlebury College and Bennington College—would likewise be good for Green Mountain.
Sealing the deal was the cost-effectiveness of the fuel source, notes Manning. Assuming fuel oil is running at $2.50 per gallon, the cost to burn 260,000 gallons would total $650,000 each year. Compare that to burning 5,000 tons of woodchips at $50 per ton—a total of $250,000—and it's easy to see the annual savings of $400,000 can quickly stack up, says Manning. "In fact, the cost of oil would have to be less than a dollar per gallon to have the same cost efficiency as woodchips."
When fully commissioned, the $5.8 million plant will have a projected payback period of 18 years. It already offers environmental, economic, and educational benefits, says Manning. "Previously, 60 percent of the college's carbon-related emissions were the direct result of our fuel oil. Our biomass plant will reduce that impact by 50 percent while providing 85 percent of the college's heating needs."
In addition to lower fuel costs, buying locally sourced woodchips that are derived from beneficial forest thinning allows the college to directly invest in the regional economy and support renewable energy production in the state of Vermont, adds Manning. And, the design of the plant as a learning laboratory—complete with catwalks and viewing areas—allows students and members of the public to observe and learn about the process.
With the transition to biomass, institution leaders decided against getting rid of the old fuel oil boiler system. Instead, it incorporated it as a redundant system, says Manning. "If we ever have a problem with the biomass plant, or if we need more heat, we can kick on one or both of the boilers," he explains. Once the plant is running at full capacity, the college expects to reduce its use of fuel oil—essentially used only on the coldest days of the year—from about 260,000 gallons per year to about 40,000 gallons.
In addition to supplying the majority of the college's heat, Green Mountain's biomass plant will generate 20 percent of the institution's annual 2 million kilowatt hours of electrical need using the steam heat to activate the system's turbines.
Another 1 million kilowatt hours—half of the college's electricity requirement—is methane-generated power purchased from the "Cow Power" program of Green Mountain's local utility. The college pays a premium for methane-generated power, compliments of Vermont cow waste. In turn, the premium subsidizes participating dairy farms in the state to encourage continued support of another renewable energy source.
KARLA HIGNITE, Universal City, Texas, is a contributing editor for Business Officer.