WAUNAKEE - Sure, the cows on the farm run by Chuck Ripp and his brothers near here generate a lot of manure — about 7 million gallons a year.
But now they also generate electricity.
Call it cow power.
Thursday, Dane County officials were joined by farmers and utility officials and others to flip a ceremonial switch and power up the state's first cooperative manure digester. Spearheaded by Dane County Executive Kathleen Falk, the $12 million project has been more than six years in the making.
When it is in full operation, the digester plant with its three huge tanks will process manure from three adjacent farms and a total of 2,500 cows. It will remove about 60 percent of weed-growing phosphorus from the manure. The digester will produce methane and that methane will be used to power generators that will churn out $2 million a year in electricity, enough to allow Alliant Energy to power 2,500 homes.
And, according to Dick Pieper, with Clear Horizons, the company that will run the plant, the entire operation can be run with an iPod.
"The efficiency of this plant is exceptional," said Pieper. "It's world class."
Falk said the plant represents an important milestone in green energy production and in manure management in Wisconsin. Many digesters don't remove phosphorus, which clogs lakes with weeds and toxic blue-green algae during warm months. But the Dane County plant was designed specifically to remove the nutrient.
"Because of this first-of-its kind digester, we will have bluer lakes and 2,500 cows producing both milk and valuable electricity to power our homes and businesses," Falk said. "We're turning millions of gallons of manure into millions of dollars worth of clean, home-grown, green energy."
Falk also praised the three farms involved in the project — the Ripps, the White Gold Dairy, and the Richard Endres dairy.
"They're the real heroes," said Falk. "When you're first at something, there are always difficulties. We spent a lot of time in their milking parlors. They stepped forward and said we know we can both manage our dairy herds and keep our lakes clean."
The manure from all three farms is pumped to the plant in underground pipes. The digester removes phosphorus and leaves liquid manure plus a solid material that can be sold for bedding for barns or for fertilizer on gardens. The liquid manure is then piped back to the farms where it is spread on fields, minus a large percentage of the weed-growing phosphorus.
A second digester plant, this one involving four dairy farms in the town of Springfield just outside of Middleton, is in the planning stages. Those farms include the Ziegler Dairy Farm, Wagner Dairy, Blue Star Dairy and the Hensen Brothers Farm.
Falk said the digester plants should serve as models for the rest of the state. "It is really important that we replicate these across Dane County and across the state," she said.