Along with the state of Maine, Colby is a participant in the Governor’s Carbon Challenge, pledging to reduce campus emissions to 1990 levels by 2010 and to 80 percent below 2003 levels in the long term. The college is in its fourth year of purchasing 100 percent renewable energy for the main campus. Colby purchases a combination of hydroelectric, biomass, and wind power. Conservation initiatives include energy-efficient washing machines, fluorescent lighting, a cogeneration turbine, and HVAC upgrades.