When Middlebury College students saw clouds in the future of their climate, they put together a plan to reduce carbon emissions on campus.
“We had a class that was asked to come up with a goal of how this could be achieved [in 2006],” says Jack Byrne, Director of the Office of Sustainability Integration at Middlebury College. “They came up with a portfolio of projects on how to achieve this. They had a good report of recommendations on how to heat campus and power electricity.”
One year and $12 million later, Middlebury College started its biomass boiler project.
Byrne says the biomass boiler ignites a gasification system, which runs on 20 to 30 thousand tons of wood chips. This system, which ultimately emits water vapor through an existing smoke stack, heats campus and provides electricity.
Middlebury College Explains
How the Biomass Boiler Works
-Wood chips are superheated in
a low oxygen chamber where
they smolder and emit wood
-Oxygen is then introduced
on the backside of the boiler
causing the gas to ignite,
producing heat (at temps
over 1100° F) to make steam
thatis distributed throughout
campusfor heating, cooling,
hot water and cooking.
-Exhaust from this process
circulates through a cyclone
separator, forcing larger
particles to drop out.
-The exhaust then enters the
bag house where it passes
through a series of filters to
remove fine particulate matter.
The filtration system in Middle-
bury’s biomass plant is rated
to remove 99.7 percent of
particulates, so most of what
one sees coming from the
smoke stack is water vapor.
Click through Middlebury
College’s campus to see which
buildings run on the biomass
“The plant itself is on an existing central system,” he says. “We have steam distribution center that fuels campus. Once the wood is gasified, it makes steam, becomes pressurized, and goes through electric turbines to power 15 to 20 percent of campus electricity.
“Then, the steam [circulates] around campus, provides heat, and comes back again as water.”
Prior to going with gasification, Byrne says Middlebury heavily relied on fossil fuels to keep campus powered up.
“We were using 20 million gallons of oil per year [before the boiler],” he says. “Since then, we’ve displaced half of that, using only 1.3 million gallons of oil.”
Byrne also says that the front wall of the boiler room is glass, so it can be viewed by visitors by day, and its glowing wires can be seen at night.
“We made this visible so people can see it and ask about it,” he says. “We’re reminded we made this change in how we got our energy and we can impress on everyone that we still pan to be conservative and energy efficient.
“Other colleges are looking to make this switch, and we are a valuable resources to others.”
With the biomass boiler, Byrne says that Middlebury College aims to be carbon neutral by 2016.
“We’re paying attention to how much we need to address our own renewable energy needs,” he says.
Across New England, Stonehill College is also paying attention to its “green” needs.
Early this year, Stonehill completed its 15 acre solar farm, which is located across from its campus at the David Ames Clock Farm.
Prior to going solar, Stonehill used 15,974,455 kilowatts per hour in electricity back in FY13. As a result, the college paid $2,002,551 for electricity alone.
However, the solar field is expected to save Stonehill over $185,000 per year, and up to $3.2 million over the course of 15 years. And, with 9,152 solar panels, the solar farm provides up to 20 percent of the campus’s electricity.
Craig Binney, the associate vice president for finance and operation at Stonehill says that up until ten years ago, the prospect of a solar farm was just talk.