Colby's biomass heating plant, completed in 2012, substantially cut the College’s emissions.
Colby’s biomass heating plant, completed in 2012, substantially cut the College’s emissions.

When it comes to carbon-neutral campuses, 668 colleges and universities have signed the pledge. On April 4 Colby became the first among NESCAC, Ivy, and comparable colleges to achieve net zero carbon emissions.


Colby is the fourth in the nation and the largest institution to reach the goal to date, according to David Hales, president of the nonprofit Second Nature, which supports the American College and University Presidents’ Climate Commitment and its 668 signatories.

The achievement was a decade in the making, as Colby worked to calculate, reduce, and prevent greenhouse gas emissions.

A tradition of Yankee thrift has made energy efficiency projects a priority at Colby for many years. Cogeneration of electricity at the steam plant started in the late 1990s, and energy improvements have been part of renovations since the Arab oil crisis 40 years ago.

Having switched to sustainably generated electricity contracts 10 years ago, the College came within striking distance of net-zero carbon emissions after its new biomass fueled heating plant became operational last year. Though the plant wasn’t running at full capacity as systems were tested and adjusted, Colby purchased 700,000 fewer gallons of oil in 2012 than in previous years, according to Director of Physical Plant Patricia Whitney.

While there is some disagreement whether sustainably harvested biomass is “carbon neutral” or “carbon lean,” Colby used national standards established by the nonprofit Clean Air-Cool Planet for calculating carbon emissions and then hired an independent firm to check and confirm methodology and calculations.

Both the College’s analysis and that of Competitive Energy Services of Portland agreed that after all the measures to reduce emissions, the College still produces about 8 million tons of carbon dioxide a year. The biggest source is transportation—both employee and student commuting and business travel by employees. 

The final piece of achieving carbon neutrality was purchasing carbon offsets—investing in greenhouse gas reduction projects elsewhere in Maine and the United States that countervail Colby’s remaining emissions. Those offsets, which invest in projects including preventing methane from going into the atmosphere at the Presque Isle landfill for example, cost $50,000. That amount is more than covered by fuel cost savings of biomass and is expected to decline as Colby continues to reduce emissions.

Vice President for Administration Doug Terp ’84 said shifting from oil to biomass saved Colby $1.2 million in the first year. And, he told employees in April, “instead of spending a couple million dollars that goes out of the state of Maine, and much of it out of the United States, the bulk of our fuel purchases now, on the heating side, are going back into the woods of Maine, which is supporting the local economy.”

For additional information on Colby’s carbon neutrality, including answers to frequently asked questions, see