Middlebury

Willow biomass experiment, now in year two, looks promising

July 14, 2008

MIDDLEBURY, Vt. - With spiking oil prices making businesses and homeowners wonder how they'll budget for winter heating, the prospect of growing renewable fuel in nearby farm fields is ever more tantalizing. This hope for a local, renewable fuel source is what prompted Middlebury College to develop a test site on the outskirts of campus to explore the feasibility of fast-growing willow shrubs as biomass. The college will open a new biomass plant on campus in December, 2008, replacing half of its more than 2 million gallons of fuel oil with regionally-grown wood chips.

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Now in year two of a four-year test - conducted by the State University of New York (SUNY) College of Environmental Science and Forestry - the college still faces many questions about whether willow can be part of the fuel solution, but the plants are growing vigorously, so far resistant to wet, drought and pests. The nine-acre test plot holds 30 different varieties of willow shrubs, creating a colorful patchwork of shape and texture.

The shrubs reach maturity at three years, and if the willows appear to be a viable source for chips at the end of the test period, the college will contract locally to plant 400 acres per year for three years. This would allow a 400-acre annual harvest, helping the college through the peak winter months when the local supply of wood chips is leanest. At that rate, the locally grown willows would supply a quarter of the college's heating fuel supply, in effect replacing 500,000 gallons of heating fuel.

Director of Business Services Tom Corbin, who spearheaded the willow experiment, says there are many questions still to be answered during the test period before going forward with a large-scale planting. He recalls, for example, that the planting machine had a difficult time with the heavy clay soils for which Addison County is famous. He also needs to identify which area farmers are interested in raising a new crop like willow.

And, of course, there is the harvesting question. Willow harvesting is done with a traditional corn harvester outfitted with a special head for chopping the woody willow stocks. Such harvesters are in short supply at this point, so the college would need to borrow or buy the specialized equipment. A potential benefit to farmers, however, is that the crop would be harvested at a time of year long after traditional crops have been brought in.

Still, despite the many questions, the prospect of producing renewable fuel so close to home is exciting, and the idea that it could infuse some money into the local farming economy makes it even more attractive. "One of our main goals is to retain control over sustainability practices during
the growing and harvesting process," says Corbin. "If this works, we could ensure that all the chips we produce are 'green' and that we're not trading one environmental problem for another."

Middlebury College Forester Steve Weber, who has worked with the SUNY team to get the research project going, says there's a long way to go, but he likes the idea. "It will be a big challenge to see this actually on the scale that we need, but it would be great to actually see it come to fruition."

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