Prize winning anaerobic digester generates interest in biogas
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| Haubenschild Farms is one of 13 AgStar farms in the United States, and is home to Minnesota's only fully operational anaerobic digester. |
Dennis Haubenschild didn't set out to win awards or become an unofficial spokesperson for renewable energy when he built Minnesota's first anaerobic digester on his 1,000-acre dairy farm in 1999, but he accepts those things as a byproduct of success.
The Princeton, Minn., resident converted his old manure lagoon into a methane plant to dispose of cattle waste in a way that would benefit his business and community. "In farming, you have to work with Mother Nature," Haubenschild said. "If you are not an environmentalist, you are not going to be successful."
Honors, revenue take second place to dream of sustainability
Successful is an apt description for Haubenschild's anaerobic digester, which produces enough methane from 1,000 cows to power the farm's dairy operations and 78 homes as well. "We agreed to purchase whatever excess power the digester produced, but it certainly exceeded our expectations," said Henry Fischer, business and community development manager for East Central Energy, Minnesota's oldest electric cooperative. "It's been a win-win project for all of us."
Haubenschild Farms has won its share of attention for anaerobic digestion, receiving the 2001 Governor's Excellence Award, the 2002 Minnesota Environmental Initiative Award for Energy Efficiency and Renewable Energy and a Rural Conservation and Development Award from the U.S. Department of Agriculture. But even the monthly checks from East Central Energy for the 100,000 kWh the electric cooperative purchases from his system are just "icing on the cake," Haubenschild said.
The real reward was putting into practice a renewable energy technology that had intrigued him for 25 years. "I first learned about anaerobic digestion while doing a history project in college," the dairy farmer recalled. "Germany used anaerobically produced methane to produce electricity during World War II."
Financing grows with interest in renewable energy
Haubenschild continued to research the idea of using cattle manure, an abundant renewable resource on a dairy farm, to make the family business energy self-sufficient. Banks, however, were skittish about making loans for such "experimental" projects.
Then, in 1999, the Haubenschild operation was chosen as one of 13 charter farms of AgSTAR, a joint program of the U.S. Environmental Protection Agency, U.S. Department of Energy and USDA. AgSTAR provided Haubenschild with $40,000 in technical assistance.
Minnesota's own agricultural energy program started to gather steam at that time, and the Haubenschilds were able to secure a $150,000 no-interest loan from the Minnesota Department of Agriculture and an $87,500 construction grant from the state Department of Commerce and Office of Environmental Assistance. The family contributed $77,500 to the total project cost of $355,000.
Digester pays itself off in short time
The cost of setting up the anaerobic digester did not daunt Haubenschild, who expects to pay off the digester in only five years. The methane-generated electricity covers what would be a $2,000 monthly power bill for the dairy, and the farm makes another $4,000 a month selling surplus electricity to their electric cooperative. Haubenschild's wife Marsha said, "It's nice to receive a check from the utility rather than having to write them one."
East Central Energy remarkets the power they purchase from the Haubenschilds to their green power customers. The customers can choose between biogas power or wind power the co-op buys through its generation and transmission cooperative, Great River Energy for the same price.
Great River Energy has been impressed enough by the 98-percent reliability rate of the Haubenschild Farms power, and its environmental benefits, to create a grant program to encourage the development of biomass energy. Member cooperatives Lake Region and BENCO received the first two $100,000 grants. "In a state that has as much agriculture as Minnesota does, we can't afford to ignore that opportunity," explained Gary Connett, Great River's manager of demand-side management and member services.
Benefits to agricultural industry make technology more attractive
The fringe benefits of anaerobic digestion are perhaps its strongest selling points in dairy country. In addition to alternative energy, the digester process greatly reduces greenhouse gas emissions, pathogens, and most noticeably, the smell associated with 24 gallons of manure per cow per day. Before the farm began using the digester in 1999, the smell of freshly mixed and spread manure would drift 2 or 3 miles and last four days. Now, a much milder smell from the digested effluent disappears overnight after spreading.
Also, by spreading the leftover nitrogen-rich digestate on the fields, the farm has reduced its use of petroleum-based fertilizer and saves the 34 gallons of propane or natural gas per acre needed to make anhydrous ammonia.
Haubenschild and others believe that plants more easily absorb nutrients from digested manure than from conventional dung or commercial fertilizer. That theory, along with weed seed destruction and economic feasibility of the digester are subjects of a three-year study by University of Minnesota researchers, now in its second year.
Haubenschild expects to use the study results when he speaks to groups touring his farm, makes presentations to environmental organizations or testifies before government agencies about the project as he did to the Minnesota State Senate in 2001.
Because, for Haubenschild, the most important product of his anaerobic digester is the interest it has created in a common-sense approach to sustainable agriculture. "It's a simple process that works with nature, and it doesn't interfere with the dairy operation," he asserts. "It should be part of everybody's manure management plan."
