Meet the Vermont Tech community anaerobic digester project
This exciting college project supports education for Vermont’s future, local agriculture, and sustainable renewable energy. Our farm & community anaerobic digester uses a two-stage, mixed substrate technology from Europe and will be powered by a mixture of farm manure and clean food ‘residuals’ to produce renewable electricity for Green Mountain Power, renewable heat for the college, and recycled nutrients for our farm community. Long before the legislature passed Act 148, which bans all organic materials from landfills by 2020, this AD project was driven by the goal of using food residuals to produce renewable energy and prove that diversion of organics from landfills was a worthy goal for Vermont.
Our project partner is the Vermont Sustainable Jobs Fund. The Vermont Environmental Consortium and the Central Vermont Solid Waste District played instrumental roles in earlier phases of this project. Project feasibility and capital funding comes from grants from the U.S. Department of Energy, obtained with the help of U.S. Senator Patrick Leahy, and bond funding from the Vermont State Colleges. And invaluable help and funding have been provided by many other generous organizations and individuals including: Vermont’s Clean Energy Development Fund, the Vermont Agency of Agriculture, Food and Markets, the Vermont’s Agency of Natural Resources, Vermont’s Department of Public Service, the SPEED program, the Natural Resource Conservation Service, the Kresge Foundation, the town of Randolph, and the Tri-Town Alliance.
This material is based upon work supported by the U.S. Department of Energy under Award Number DE-FG36-08GO88182.
Why anaerobic digestion?
We are all increasingly concerned with energy prices, energy security and the availability of energy. We all want to protect our agricultural heritage and see farming continue to be an important part of our working landscape and our economy. At Vermont Tech we want to be part of the solution!
We have integrated renewable energy, green building and sustainable land use practices into our curriculum, and have installed a variety of renewable energy projects on campus. This project is part of that larger process and a critical asset for practical education in agriculture, renewable energy and sustainable technology.
What is anaerobic digestion?
Anaerobic digestion (AD) is a natural biological process used by ruminant animals like cattle, goats and sheep to extract energy from food. Our AD facility will use the same natural biological process that occurs in the four stomachs of a cow. While cows use feed to produce milk, meat and more cows, our facility will use dairy manure and food ‘residuals’ to produce electricity and heat for Green Mountain Power and the campus. Like a cow, this anaerobic digestion facility will produce manure-like material that will allow us to recycle nutrients from food residuals into crop fertilizer.
In many senses, anaerobic digestion offers more environmental benefits than other renewable energy technologies because:
- AD operates 24/7, not just when the sun is shining;
- ‘Waste’ heat will be used to heat buildings;
- Digestion turns wastes, truly resources that have already been used once, into renewable energy;
- While it recycles the nutrients in those wastes and;
- Allows us to properly manage those nutrients; and
- Creates another way for farms and communities to work together for fiscal and environmental ends.
We are committed to working with our community to recycle organic wastes and create renewable energy. We are talking to nine neighboring farms about regional nutrient management planning: the college will provide NMP services, digester nutrients, and field application for farm partners. Some farms will also supply us with feedstock.
Food residual feedstock will also be sourced from the community. We’re developing partnerships with local businesses to supply cheese whey, buttermilk, brewery residuals, grease, and other food processing wastes. We are working with a local composter to begin collection of food residuals from the greater Randolph community in early fall. By spring we hope to digest community food residuals that are now being landfilled.
Costs and fiscal payback
While the state is working out the most effective means of implementing Act 148, a law passed in 2012 that bans all organics from landfills by 2020, the college is pioneering pathways to implementation. Our work will provide a model for successful implementation or cautionary data about what may not work.
Of course, while environmental and social impacts of the VTCAD are important so is the fiscal bottom line. The project began with a feasibility analysis that included fiscal costs and benefits. During construction and our first years of operation we hope to collect fiscal data and to make that available to the college and community. This data may be of interest to programs and faculty teaching business planning and fiscal modeling.