COMMUNITY POWERED
AURI is helping rural communities analyze the economics of anaerobic digesters

By DAN LEMKE

Is it economical for Minnesota communities to turn waste into power? AURI now has a tool to help find the answer.

Anaerobic digesters that break down agricultural and food processing wastes to produce energy may benefit municipalities as well as farms. Minnesota livestock facilities are closely monitored for potential environmental impact from odors and from nutrients in surface and ground waters. Food processors pay fees to dispose of waste though regulated land applications or sewer systems.

To help communities and producers determine if a jointly-powered digester is feasible, AURI has produced a self-assessment booklet: The Appropriateness of a Community Manure Food Waste Digestion System. "This is really a pre-assessment for producers and communities to see if they have the resources for a community facility using municipal and agricultural sources," says Michael Sparby, AURI project development director. "Products that were once thought of as waste are now being looked at as a resource."

Anaerobic digesters use bacteria to break down solid wastes. As a result, the bacteria give off methane gas that can be captured and used for heat or electrical generation. The treated solid waste is then safe for land application or other uses. Since digesters operate most efficiently with a high volume of solids, mixing manure with food processing wastes can take the pressure off municipal systems and improve digester operations. The assessment calculates the size and proximity of livestock and food-processing facilities to determine if enough waste is available.

"No one component is going to make it work," Sparby says. "It's a matter of matching up technical issues such as location and supply of feedstocks with the economics of the project. That includes things like construction costs and if you can obtain a purchased power agreement."

"This tool helps put the puzzle together. If the pieces aren't all there, then you've saved a lot of time and effort. If they are, then maybe it's worth pursuing further."

Sparby stresses the report is not designed for any particular community. However, Perham, Minn. is considering a digester, and a system in Oregon has already started operating.

For a copy of the self assessment guide, contact Michael Sparby at AURI: (320) 589-7280.