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At a Minnesota dairy, Holsteins are in the energy business

A project that uses manure to make electricity reignites interest in an unusual renewable. Call it 'cow power.'

By Tim KingSpecial to The Christian Science Monitor / November 21, 2002


Each Holstein on Dennis Haubenschild's dairy farm chomps down 90 pounds of feed, yields eight gallons of milk, and produces 220 pounds of manure (including the shredded newspaper bedding) - daily. It's a pretty standard operation in the dairy industry.

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But his 750 cows are also in another business with a different product line: Every one of the half-ton beasts generates 4 kilowatt hours of electricity a day.

Locals call it "cow power," and it keeps the lights burning and supper warm in 75 rural Minnesota homes north of Minneapolis.

The cow-to-electricity operation on Mr. Haubenschild's farm is part of a born-again interest in putting to good use a problematic farm-waste product - that is, gigantic loads of manure. While overall investment in such "waste-to-energy" efforts is small, in the range of $20 million, interest is higher today than at any point since the 1980s, say enthusiasts.

For Haubenschild, the benefits are numerous. The manure is contained in a covered pit, so his downwind neighbors can smell the daisies instead of nose-stinging cow excrement. The pit is cement-lined, so the waste won't seep into the groundwater or run off into rivers and streams. The methane gas that is produced as the manure decomposes is channeled into use as a renewable energy source, rather than dispersing into the atmosphere, where it would contribute to global warming. What's more, his cows generated $81,000 worth of electricity last year, helping to keep the farm in the black during times of low milk prices.

If it's such a brilliant solution, what took so long?

The answer, as is often the case in localized energy projects, is money. Dairy farms already operate close to the margin, and finding the dollars for the initial investment is no easy matter. Methane-fired electricity generators don't come cheap, and they need to be individually designed (bring on the engineering consultants) to fit the circumstances of each farm.

A harmonic convergence

Haubenschild, who has been interested in this renewable technology since the 1970s, finally saw his opportunity in the late 1990s - and seized it. The US Environmental Protection Agency was increasingly concerned about methane gas (a greenhouse gas 21 times as potent as carbon dioxide), and Minnesota agriculture officials, meanwhile, were fretting over declining farm incomes. With a patchwork of state and federal grants, and with help from the University of Minnesota and a nonprofit group called the Minnesota Project, Haubenschild was able to build a $350,000 electricity-generating plant on his 1,000-acre farm. His idea was that the plant would demonstrate that his dream of electricity from manure was feasible.

He was right.

"I had no doubt that it would work," Haubenschild says. "It just took quite a few years to tie everything together."

When Haubenschild's system was completed in 1999, his was one of only 31 electricity-generating methane harvesters on US farms. But its success exceeded even the engineers' expectations, and published reports about its merits are reviving interest in the technology.

"As of spring 2002, there were over 40 digester systems in operation at livestock farms in the United States, with dozens more in the planning stage," the Minnesota Project wrote in its August report on Haubenschild's generator.

One man who was not surprised by the results is Dick Waybright of Mason Dixon Farms, near Gettysburg, Pa. He has used a similar system for more than two decades.

It is an "important part of our profit picture. We get 30 percent or better annual return on our investment," says Mr. Waybright, who milks 2,150 cows with his sons.