Gundersen Health System will check off another project on its bucket list toward energy independence today when it marks the completion of its joint cow power project near Middleton, Wis.
The $14 million GL Dairy Biogas Farm, a joint venture with Dane County, has been producing methane and electricity from cow manure since late last year, said Corey Zarecki, director of Envision, a Gundersen subsidiary that cultivates environmental and sustainability programs.
After being tweaked for several months, the plant was ready for its unveiling ceremony this morning.
The plant collects manure from more than 2,000 cows on three area dairy farms that is sent to digesters to create methane to run engines and a generator to produce electricity, Zarecki said.
Dane County contributed $3.3 million toward the project, which also received a $2.2 million federal grant, and the rest came from Gundersen, which expects a six-year payback, he said.
Gundersen owns the plant and sells the electricity — enough to power about 2,500 homes — to Madison Gas and Electric Co., with byproducts such as compost, bedding, liquid fertilizer and other materials also being sold for a total revenue of about $2 million a year, he said.
That is equivalent to about 14 percent of the health system’s annual energy costs in its quest to be energy independent this year.
“We’re pushing for that. We’ll have a good indication of that by the end of this month or November,” Zarecki said.
Added benefits are that the process reduces algae-producing phosphorus in runoff from the liquid manure used on farm fields and decreases the amount of fossil fuels burned, he said.
In remarks prepared for the ceremony, Dane County Executive Joe Parisi said, “The cow power project paves the way for home-grown renewable energy, cleaner lakes and keeping our dairy farm families milking cows for generations to come.
“Dane County is the 23rd-largest dairy-producing county in the nation, and we are turning all that milk into green energy to power our homes and businesses,” Parisi said.
The digesters also will reduce greenhouse gas emissions by 22,000 tons a year, which the Wisconsin Department of Natural Resources says is equivalent to carbon dioxide emissions from more than 4,000 cars.
The dairy biogas project is similar to Gundersen’s partnership with La Crosse County in an award-winning project that taps the county landfill for methane to produce electricity. Gundersen sells the electricity to Xcel Energy and also uses it for power and heat for the health system’s Onalaska campus.
La Crosse County also benefits financially from the partnership with payments from Gundersen for the methane.
Through August, the county had received $112,000, said Hank Koch, solid waste director and landfill manager. It received $216,000 last year, and $178,000 in 2012, which was for only part of the system’s inaugural year, Koch said.
That project “saves on taxes and reduces the cost of health care,” Zarecki said.
The Onalaska campus has been energy independent since 2012, saving about $500,000 a year, Zarecki said.
Biogas “is a great renewable energy source,” he said.
“We’re hoping to kick-start it, and eventually hope to make it more pervasive and allow individual farmers to use it,” he said.