Guide to Anaerobic Digesters

As of November 2007, AgSTAR estimates that there are 111 farm-scale digesters operating at commercial livestock farms in the United States. Four of these installations are centralized systems that provide manure treatment for multiple farms.

In 102 of the 111 operational systems, the captured biogas is used to generate electrical power, with many of the farms recovering waste heat from the electricity generating equipment for on-farm use. These systems generate about 170,000 MWh of electricity per year. The remaining nine systems use the gas in boilers, upgrade the gas for injection into the natural gas pipeline, or simply flare the captured gas for odor control.

In total, the combustion of biogas at these digesters prevents the emission of about 29,000 metric tons of methane annually (610,000 metric tons of CO₂ equivalent). In addition, this biogas utilization displaces the use of fossil fuels, thus achieving additional emission reductions of greenhouse gasses and air pollutants.

Anaerobic Digester Database

The Excel spreadsheets below provide basic information for anaerobic digester systems in the United States. The spreadsheets show projects in the following stages: planning, design, construction, startup, steady state, shutdown, and cancelled. Download XLS viewer.

• Anaerobic digesters, sorted by operational status and by state (XLS, 82KB)
• Startup and steady state anaerobic digesters, sorted by state (XLS, 54KB)
  • Dairy projects (XLS, 47KB)
  • Swine projects (XLS, 25KB)
  • Beef cattle (XLS, 21KB)
  • Poultry (XLS, 22KB)

These data were compiled from a variety of sources. AgSTAR cannot guarantee the accuracy of these data. AgSTAR encourages farm operators, project developers, financers, and others involved in the development of farm digester projects to provide updates and corrections to these data by contacting AgSTAR.

Farm Project Profiles

Anaerobic digester systems can be installed successfully at commercial scale operations that collect manure as a liquid, slurry, or semi-solid. Existing farms use a variety of different types of digester designs and energy use technologies. Read profiles of successful anaerobic digester projects that are enjoying the environmental and economic benefits of incorporating anaerobic digesters into their manure management system.

• AA Dairy
• Barham Farms
• Gordondale Farms
• Haubenschild Farms
• Mason Dixon Farms
• Royal Farms

EPA Home | Privacy and Security Notice | Contact Us