A Long-Time Dream Fulfilled

Dennis and Marsha Haubenschild run their family dairy farm in Princeton, Minnesota. For years they toyed with the idea of turning manure waste into a useful energy source but, until recently, they rejected the idea because they associated it with high risks and costs.

However, when their sons, Tom and Bryan, joined the dairy farm in 1997, they increased their farm’s capacity to accommodate 1000 dairy Holsteins. The larger herd prompted the Haubenschild’s to reconsider their waste management system and fulfill their long-time dream of turning waste into energy. The dream was no small idea, however, since there were only 27 manure digesters operating on livestock farms across the country and less than half of those were on dairy farms.

Economical Energy Source

Since 1999, the Haubenschild’s have been operating an anaerobic methane digester, which:

* controls odor,
* creates energy and
* provides important soil nutrients

for the feed crops grown on their land. In the winter, the Haubenschild farm produces enough methane from their dairy cows to power their entire farm facility and several nearby homes.

“We didn’t use any propane all winter,” Dennis says. He also stated that he saved 35 tons of coal and 1,200 gallons of propane in the month of January alone.

While experts initially thought the system might have a 10-year payback, they are now expecting it to be less than 5 years. Responding to the success of the digester, Dennis remarked, “I had no doubt that it would work; it just took quite a few years to tie everything together.”

Financing their Dream

Initial financing, for example, proved difficult as many traditional lenders rejected their loan requests. They began seeking assistance from nontraditional sources. Their first success was in qualifying for a $150,000 zero-interest loan program that the Minnesota Department of Agriculture developed in 1998. Other state and federal agencies chimed in over $120,000 to supplement the project. The family paid $77,500 in remaining expenses.

How it Works

A manure collection and blending pit is under the engine room where 20,000 gallons of manure, along with recycled newspaper bedding, moves underground to the blending pit every day. Onceblended, it is sent to the heated straight flow plug digester. The digester is heated to approximately 100 degrees encouraging the production of anaerobic bacteria which produces methane. The manure plug is designed to cycle a day’s manure through the pit in 20 days.

“The plant is now producing more gas than we expected,” says engineer Mark Mosser. The reason may be that newspaper bedding is high in cellulose. Cellulose is highly digestible for anaerobic bacteria. Straw bedding, on the other hand, is high in lignin and not very digestible.

Cooperative Efforts

“We use a 1000 pounds a day,” say Bryan Haubenschild. “We get it free from a local publisher. All we have to do is pick it up.” After the newspaper bedding and manure have been digested and extruded into the manure lagoon, the material is ready to spread.

Dennis estimates the largely odorless digestate from the lagoon is worth about $40,000 annually. “The nitrogen is much more readily available than regular manure,” he says. The digestate has an excellent water holding capacity and a pH of 7.4 which makes it an excellent soil builder on Haubenschild’s sandy, slightly acid soils. “Soil is a living thing and the microbial activity of the digestate is very high,” he says. “I think it will have a positive impact on soil life,” predicts Haubenschild.
The ‘biogas’ produced is directed to an engine and generator, which converts it to electricity and hot water. A third of the electricity returns to the farm to power the milking parlor and other operations, while the other two-thirds is sold to East Central Energy, the local electric cooperative. TheCooperative has agreed to purchase the Haubenschild’s surplus electricity at full retail rate beyond what the law requires.

According to Henry Fisher of East Central Energy, the Haubenschild’s will produce over 100 kilowatts when fully operational, but the utility will continue to purchase it at retail rates as long as they can roll it into their green pricing program. “We view this project as an opportunity to make full use of renewable energy resources and promote sustainable agriculture,” Henry says. “We take that energy and roll it into our green power program where we can charge a premium over the retail rate to cover our distribution costs.”

Promoting Self Reliance

Dennis has been encouraging the state to assist other farmers in becoming more self-reliant. For example, he recently testified before the state legislature to increase funding from $200,000 to $10 million for manure-processing and odor-control projects. The fund would allow farmers with similar dreams to seek an interest-free loan for up to $200,000.

To increase awareness, the Haubenschild’s have also been conducting tours of their facility, so that farmers and other interested minds can see how the digester operates.

Roger Frederick, who operates a 500-cow dairy near Waseca, said the digester is a step in the right direction for manure management and he is exploring the feasibility of doing something similar on his farm. Roger is not the only dairy farmer in Minnesota who has been inspired by the Haubenschild’s success.