A microturbine generator that runs on methane biogas from animal manure will be evaluated as a source of electricity and heat for a research dairy farm in a cooperative project of the Agricultural Research Service (ARS), the US Department of Energy's Office of Bio-Power and the National Energy Technology Laboratory.
The microturbine system could generate as much as 26 kilowatts of electricity and approximately 400,000 British thermal units per hour of heat for small dairy operations of less than 250 cows.
"This project is an example of the positive partnership between US Department of Agriculture and DOE to combine resources and capabilities to develop renewable energy for on-farm use, while also addressing an animal waste management issue," said Rodney J. Brown, USDA deputy under secretary for research, education and economics. "A system that operates efficiently and is cost-effective would provide an alternative energy source for dairy farmers and help them to lower their operating costs."
"This system will help produce renewable energy to restore our nation's energy vitality and protect the environment while enhancing the rural economy," said Richard Moorer, deputy assistant secretary for technology development within DOE's energy efficiency and renewable energy office.
The Department of Energy provided the microturbine generator. Acting research leader Louis Gasbarre and his colleagues in the ARS Animal Manure and By-Products Laboratory will oversee operation of the microturbine system's test periods and provide analysis for manure, methane and greenhouse gas emissions.
According to a report this week the technology aims to provide an alternative use for dairy cow manure. The researchers report that tons of manure are produced by the 1,400-pound dairy cows and pumped from the barn into an anaerobic digester, where the liquid and solids are separated. The solids go to composting, and the liquids are further processed in the digester to produce a biogas that contains methane. The methane gas is captured and used in the microturbine generator, and the remaining liquid - happily with odour significantly reduced - is used for fertilising crops.
The ARS research team will also evaluate the technology's environmental and economic impacts. If this type of system proves to be efficient and cost-effective, it could provide an alternative, and much cheaper, energy source for dairy farmers.