Vermont’s Killington Resort, the largest ski and snowboard resort in Eastern North America, announced last week that it will power its K-1 Express Gondola during the 2012-13 season with electricity generated directly from cows on Vermont dairy farms. The initiative was made possible through Killington’s enrollment in Green Mountain Power’s Cow Power program, which enables GMP customers to purchase all or part of their electricity at a premium and support Vermont’s dairy farms as well as the development of new cow power projects across the state.
The GMP Cow Power process involves farms collecting cow manure throughout the day, mixing it with wash water from the milking equipment which is then pumped into an anaerobic digester. The slurry flows through a digester for about three weeks at 100 degrees Fahrenheit allowing bacteria to convert the manure into biogas, about 60% methane gas and 40% carbon dioxide. The biogas is then delivered to a modified natural gas engine, which drives an electric generator to create electricity. Finally, the energy generated is fed onto the GMP electrical system which ultimately powers the K-1 Express Gondola.
The left over manure in the digester does not go to waste; it is separated into solid and liquid portions. The liquid portion is used as enhanced fertilizer and the solids, consisting of plant fibers including grass, corn stalk fibers, grain hulls, etc. can replace sawdust as bedding for the cows.
Currently, 13 Vermont farms, with roughly 10,000 total dairy cows producing 300,000 gallons of manure per day, participate in the GMP Cow Power program and are compensated for their electric generation and the related environmental benefits. The energy is used locally and the program continues to grow annually with new farms and new customers joining regularly.