How Green Is Our Valley?
Talkin' 'bout Cogeneration
"People don’t want to think about how the light and heat get into a classroom, they just want to flip a switch and have them work,” notes Energy Manager Todd Holland. Once Amherst’s new cogeneration plant comes on line, though, it might be a good idea to start treating engineers like rock stars.
Cogeneration is the cutting edge of power plant technology. Anyone who’s ever set foot in a power plant knows that these buildings tend to be warm. That’s not a good thing; the ambient heat you feel is wasted energy. Physics professor Larry Hunter notes that even the best electrical plants are only about 40 percent efficient: “Most of the energy is simply thrown into the environment as waste heat,” he says. What if, somehow, that heat could be harnessed? That’s precisely the idea behind cogeneration plants, the “co” referring to a facility that produces heat (or cooling) and electricity at the same time. In Hunter’s words, “The concept of cogeneration is simply to use this waste energy to heat buildings and hot water.”
Cogeneration plants, also called CHP for “combined heat and power,” are perfect for campus settings like hospitals and colleges, as they are most efficient when generators are located near to the buildings they service. (Unlike electrical wires, heat and air conditioning move through large ducts; the further they travel, the more energy is lost.) Hunter notes that the University of Colorado’s CHP facility increased electrical efficiency from 34 percent to 70 percent. Facilities Planning Director Jim Brassord predicts a similar result for Amherst College.
When the new plant comes online, Professor Richard Fink’s students will be there to measure the results. Analyzing the workings of the college steam plant is a standard feature of his “Energy and Entropy” course. He believes that with cogeneration students will measure a more efficient use of energy with less direct degradation, the entropy side of things embedded in the second law of thermodynamics.
The study phase for the new plant has been completed. Holland and Brassord are currently consulting with designers and hope to have a plant operational by mid-2007. Holland is also consulting with Mount Holyoke and Smith on similar projects. If all goes according to plan, these three new facilities, plus a larger one being phased in at the University of Massachusetts, will drastically reduce CO2 emissions and place area schools at the fore of energy conservation efforts. There are currently just six similar facilities in all of Massachusetts and fewer than 150 among all the colleges in the U.S. and Canada.
The Amherst College plant is budgeted at $5 million, but will pay for itself in less than five years. This prompts a question: If CHP plants are such a good idea, why aren’t they ubiquitous? They probably will be now that energy costs have soared. Brassord explains, “One has to consider the core business of any enterprise. For a college it’s teaching and research. Until recently a non-core issue like a power plant took 12 to 15 years to see a return on its investment. The payback time has now dropped dramatically, and energy investment now serves the mission of the college.”
Both Holland and Brassord caution, however, that cogeneration isn’t a panacea. It must be part of a comprehensive and enduring effort to stay ahead of the rising energy curve. Until the CHP plant is operational Holland grades Amherst’s current efforts a gentleman’s B-. “The college has the ability to go the head of the class,” he says, “but the priority to be energy smart hasn’t been there until finances began to drive it, and the rest of the campus needs to catch up.” Brassord agrees that Amherst’s challenge is to continue to improve. “Sustainability is never fully achieved. By nature, as a college we consume resources, so we must constantly be on the lookout for energy conservation opportunities and new technologies. Environmental stewardship is a core belief of the college and must remain so.”
Meaghan Kemp-Gee ’07 applauds efforts like the cogeneration plant and is bullish about the path Amherst has taken: “Change won’t start with politicians, but with institutions like Amherst showing the way,” she says. “Amherst College is grooming the future leaders of the global community, but we’re uniquely poised to lead now. Amherst has the best and brightest people and the resources to make a difference.”
The author is a freelance writer and historian based in Northampton, Mass.
Photos: Samuel Masinter '04