On March 13, 2012, fifteen students, faculty and staff joined the Clean Energy Fund for a tour of the McNeil Generating Plant in Burlington’s Intervale. Undergraduate representatives from the Clean Energy Fund committee were in attendance, as well as students from disciplines as diverse as Engineering and Plant and Soil Science. Plant Manager John Irving—who originally worked for the Boston company contracted to build the plant, which went into operation in June, 1984—took us on an hour and a half long tour of the plant, from the huge wood-fired boilers housed in the plant itself to the massive piles of material in the waste yard behind it which fuel the generating station.
McNeil currently supplies over 1/3 of Burlington’s electricity, although it operates at only about 1/3 of its generating capacity, usually to accommodate peak winter and summer electricity loads. Operating at its full capacity of 50 MW, McNeil can, in a pinch, supply Burlington with most of its electricity needs on a short-term basis; and indeed, Burlington went relatively unscathed in the massive 2003 Northeast blackout. To put McNeil’s power generation into perspective, Vermont Yankee nuclear power plant has a capacity of 620 MW, 80% of Vermont’s total electricity generation.
McNeil was born out of the energy crisis of the 1970s, when oil and natural gas prices were at an all-time high and energy independence was a priority. By and large, Burlington residents welcomed the idea of a woody biomass electric generating station, and over 70% of residents voted in favor of building McNeil back in 1978; however, the potential impact of the nearly continuous line of trucks to supply the plant was a major concern, especially to the citizens of Winooski, who would bear the brunt of the traffic while Burlingtonians got the electricity. So now McNeil is obligated to receive ¾ of its wood fuel by rail, which presents some logistical difficulties for the plant and its workers.
Transportation remains a significant cost in plant operation. Environmental justice advocates point out that McNeil is located in Burlington’s diverse, low-income Old North End, mirroring a trend that sites hazardous and polluting infrastructure in our poorest communities. In addition to pollution, dust and noise were concerns, and wood chip storage presented an initial challenge when the huge piles occasionally spontaneously combusted. Irving pointed out a poster from the early 1980s that proclaimed, “The Wood Chip Plant is Coming!” amidst the stumps of a clear-cut forest.
McNeil was retrofitted to accommodate natural gas burning in 1989—now, natural gas prices are so low that it would be cheaper to run the plant on natural gas. Rock-bottom natural gas prices unfortunately present a significant market barrier to alternative energy development, an issue that John Irving discussed with UVM energy experts after the tour . McNeil still burns wood—and lots of it. While McNeil rarely runs at full load, if it does, it can generate 50 MW of electricity and consume 76 tons of material per hour (that’s about 30 cords of wood). Most of the wood chips that McNeil consumes are derived from low-quality wood and harvest residues. Addtionally, the wood ash byproduct from burning, rich in potassium, is removed by a private contractor, and sold as a soil conditioner for Vermont agricultural fields. Gritty bottom ash is recycled into roads or topsoil additives.
The bulk of McNeil’s wood supply comes from Upstate NY, but Vermont’s forests also supply a significant amount of the fuel. McNeil doesn’t own any forestland, but it does employ four full-time foresters who monitor harvesting activities for environmental compliance. If forests are properly managed, electricity from biomass has a comparatively good carbon profile: McNeil displaces the use of 350,000 barrels of oil equivalent yearly. Particulate emissions are reduced 1/10 of the legally permissible level in Vermont by a series of air-quality control mechanisms. Although biomass is considered a renewable energy source because forests do grow back over time, the short and long-term impacts of woody biomass as fuel are fiercely debated, both in academia and in the public sphere.
Irving patiently explained the regional electricity market, and how RECs (Renewable Energy Certificates) work. In Vermont, woody biomass is considered a renewable fuel, and so its “RECs” may be sold on the market, in addition to its electricity. Many states require a certain amount of renewable power production, which can be offset by purchasing RECs. In a complicated twist, McNeil sells its RECs, but the Burlington Electric Department purchases other RECs, maintaining its claims to renewability at nearly 50% of the total fuel mix.
A visit to McNeil, just a 20 minute walk from campus, is well worth it; not only is the plant an integral part of Burlington’s electricity supply infrastructure, but it gives visitors a close-up view of how electricity production works, as well as an idea of the potential—and the drawbacks—of woody biomass electricity production as we weigh the costs and benefits of fossil fuel alternatives.
Many thanks to Office of Sustainability Performance Tracking Fellow Anna Mika for providing the artful photographs featured here!
For more information about the Burlington Electric Department (the city’s municipally-owned utility, which owns 50% of McNeil), visit: https://www.burlingtonelectric.com/page.php?pid=128&name=BED%27s%20Power%20Supply.
For more information on UVM’s Clean Energy Fund, a student-supported initiative which supports renewable energy projects on campus, visit: http://www.uvm.edu/sustain/cef