Anaerobic digesters valuable for odor control

From an article by Nathan Phelps in the Green Bay Press-Gazette:

Small farms hope to afford manure converters

A decade ago, anaerobic digesters were somewhat of a novelty on Wisconsin dairy farms.

Use of the systems that convert methane gas from manure to electrical power has increased in recent years in the state and nationally. With an average installation cost of $1.5 million, however, most farms have been unable to adopt the technology.

But some in the ag sector are looking at ways digestion can be brought to smaller operations.

Charles Gould, a Michigan State University Extension educator in nutrient management, said he's optimistic the industry someday will be able to deliver a cost-effective digester to farms with herds around 125 cows — the bulk of the nation's dairy farms.

"There are farms that have small digesters, but there are very few of them," he said. "The goal for the small farmer isn't going to be to produce electricity for the grid. If they're going to produce electricity, it's going to be for their own use."

Gould said he sees an untapped market for smaller digesters.

Smaller farmers "want the benefits of odor control. They want the option of bedding. They want the potential to produce electricity," he said. "They want all the advantages the big boys have, but they're not willing to pay the price.

"They must be affordable, and they must be manageable."

The discussion was part of the two-day Midwest Manure Summit at Lambeau Field in Green Bay this week that drew several hundred attendees, including farmers and businesses in the ag sector.