Digesters Make Renewable Energy From Manure, but Face Hurdles

A Danish company’s plans to turn cow manure into renewable energy in Minnesota and Wisconsin’s dairy country have tanked, at least for now.

Nature Energy planned to build several large-scale anaerobic digesters that would harvest methane from livestock waste to produce biogas. The company was eyeing three sites in dairy-rich Stearns County, as well as Lewiston in southeast Minnesota and Benson in western Minnesota.

But in August, British oil and gas giant Shell announced that its subsidiary, Nature Energy, was “strategically suspending” all of its projects in the U.S.

Shell’s abrupt change of course is a disappointment to the projects’ backers in communities such as Paynesville, where Nature Energy had proposed building its first Minnesota plant. They believed it would harness a local waste stream to benefit both farmers and the climate.

“It's looking forward in helping to protect the environment, and really bring in a new type of energy development to the area and to the country,” Paynesville Mayor Shawn Reinke said in July.

Shell’s pullback also is an indication that the promising technology of biogas still faces hurdles — including high costs, regulations, market forces and local opposition — to becoming a major U.S. energy source.

But some energy experts say it makes sense to turn the methane in manure from a liability into a commodity, especially in Minnesota — home to about 9 million hogs and nearly half a million dairy cows, which produce as much as 50 million to 100 million tons of manure a year.

“That’s a lot, and right now much of it is not really fully utilized,” said Roger Ruan, director of the University of Minnesota’s Center for Biorefining. “There’s a lot of potential here using manure for electricity generation.”







Source: mprnews.org