Clarkson University Researchers Use Dairy Waste for Energy

Cow manure, waste silage, cheese whey are waste products to some, but viable energy sources to enterprising Clarkson University researchers who are helping area farmers meet their own energy needs.

Last year’s New York State budget included a $1-million appropriation for Clarkson to investigate ways that dairy waste from cheese manufacturing and dairy farms can be used as feedstock to produce biogas to generate heat and electric power on New York farms.

“Biogas derived from the anaerobic digestion of manure and whey represents an important biofuel that could provide significant economic, environmental and social benefits at thousands of farms,” says Stefan Grimberg, associate professor of civil & environmental engineering. “Farmers and dairy processing facilities can displace purchased sources of heat and power, reduce wastewater treatment and environmental compliance costs, and mitigate exposure to fluctuating power prices.”

Grimberg is the principle investigator on a $2-million project to design and build an anaerobic digester and power/heat recovery system at a working dairy farm in Jefferson County, N.Y. The interdisciplinary research team from Clarkson also includes electrical engineers and social scientists.

The researchers will use the project to showcase emerging technologies. The project also promises to yield important improvements over current digester technologies through the development of an optimization model for the integrated energy system and through mechanisms to separate sand used for bedding from the manure.

“More than half the anaerobic digesters built before the mid-1980s failed to operate properly,” Grimberg explains. “We are interested in improving the technology and reliability of the system.”

In-depth interviews with New York state farmers that have installed anaerobic digesters are being performed in order to discern the motivations for adopting the technology as well as how anaerobic digestion technology is integrated into their farming systems.

“There is very little data available on farm-level perceptions, knowledge and attitudes toward anaerobic digester technology,” explains Associate Professor of Sociology Rick Welsh, a member of the research team. “Such data is critical to inform the design of anaerobic digesters, as well as to create public policy that can provide helpful information to farmers about their options in this area.”

The team will also complete a lifecycle accounting of the environmental benefits from diverting waste products to an energy system and the associated displacement of fossil fuel sources.

Researchers plan to use the model as a basis for extending digester/energy system technologies across the North Country, which could eventually be implemented on a wider commercial scale. “This pilot study represents that important intermediate step in technology transfer between initial laboratory research and commercialization,” says Grimberg.

The project has also received support from the New York State Energy Research and Development Authority, the Department of Energy and the United States Department of Agriculture.