“We’ve always been very good about conserving energy at the college, but to meet the goals of our sustainability plan, we knew we had to take it up a notch and begin looking at alternative energy sources so we could remove part of the campus’ drain on the energy grid,” he says.
Lizotte explains how the biodigester works: “We’re basically taking composting and moving it indoors. We’re then capturing the burnable gas the composting emits and then using that to power the generators,” he says. “The facility will have air filters so any adverse smells are removed. You will be able to walk right by it and not know it’s there. We went to see one of these at work in the middle of Munich and odor isn’t an issue at all. You don’t even know it’s there.”
Unlike wet biodigesters that are being used on some farms to deal with manure, the dry biodigester will not produce wastewater that will need to be treated or disposed.
To work, the biodigester will need 6,000 tons of organic biowaste annually to provide the 400 kilowatt output. Lizotte says the college is already planning to collect yard waste and food waste to power the biodigester, but more will be needed. Right now, the college is looking to partner with agricultural producers and perhaps the City of Oshkosh to collect food waste to use in the biodigester.
“Twenty-five percent of what goes into landfills is food waste. Just as we have pulled yard waste out of the landfill, I think food waste is next,” Lizotte says. “It’s already happening in Europe and I think it will happen here, too. For example, we can partner with a plant that cans peas and collect all the pea pods they aren’t using and put them in the biodigester. It will keep those pods out of a landfill some place and it will create energy.”
Close proximity to agriculture by-products makes Wisconsin a potential leader in using biomass to create energy, says Lizotte, adding that the college also looked at solar and wind energy options before deciding on the biodigester.
To help fund the $2.3 million construction of the biodigester, the college is receiving a $500,000 grant from the federal government and a $232,587 grant from Wisconsin Focus on Energy. The UW-Oshkosh Foundation purchased the land where the plant will be built. The goal is to have the biodigester up and running by this fall to take advantage of agriculture waste created during the harvest season.
Tom Sonnleitner, vice chancellor for administrative services at UW-Oshkosh, says the biodigester fits in well with the college’s educational mission.
“In addition to conserving energy, we’re trying to provide a living laboratory for our faculty, students and staff members regarding renewable energy and its infrastructure,” he says. “This is something we’re really excited about at UW-Oshkosh and proud to be the first place in the nation to have this technology.”
The fully-enclosed system will not produce waste products that will need to be remediated, Sonnleitner says. For example, with “wet” biodigesters, stormwater is created and then needs to be treated.
“There are no residual effects from using this technology and at the same time, we are conserving energy,” he says. “It’s a win-win.”
Lizotte says once the dry biodigester is up and running the college will offer tours and share information on how it’s working.
“We’re an educational facility and plan to use it as a learning tool,” he says. “We will be collecting data on it and will be very transparent so everyone can see how much energy we’re creating from the biomass collected,” he says.