AgSTAR Data and Trends
There are 255 anaerobic digester projects operating on livestock farms in the United States, helping to reduce greenhouse gas emissions from methane. Of these, 107 projects have been awarded grants by the United States Department of Agriculture. This page provides national market data and trends related to these biogas recovery systems.
- Potential for anaerobic digestion on livestock farms in the United States
- Anaerobic digester facts and trends
- Biogas facts and trends
- Environmental benefits
- Value of anaerobic digester biogas and coproducts
- State data and trends
You can also find information on individual anaerobic digesters operating on livestock farms in the United States, including:
Potential for Anaerobic Digestion on Livestock Farms in the United States
AgSTAR estimates that biogas recovery systems are technically feasible at over 8,000 large dairy and hog operations. These farms could potentially generate nearly 16 million megawatt-hours (MWh) of energy per year and displace about 2,010 megawatts (MWs) of fossil fuel-fired generation.
Use of anaerobic digestion at poultry and beef operations is growing as new technologies enter the market. Although these projects are technically feasible, their economic feasibility can vary.
Challenges and Opportunities for California’s Dairy Economy (PDF) Exit(149 pp, 6.4 MB, About PDF) explores the potential of dairy biogas systems to reduce environmental impacts while generating energy and/or income for dairies.
Anaerobic Digester Facts and Trends
The chart below shows the growth in the number of cumulative operating digester projects on livestock farms (Source: AgSTAR Livestock Anaerobic Digester Database).
|Year||Operational1||Newly Operational2||Shut Down||Under Construction|
1 Data provided in the table for Operational digester projects are inclusive of Newly Operational digester projects.
2 Newly Operational digester projects are projects that began processing feedstock in the corresponding calendar year.
* 2020 values are based on data as of March 2020.
** Data shown for operational digesters in 2000 represent cumulative totals from 1972-2000.
There are a number of different types of anaerobic digestion systems. Complete mix and mixed plug flow designs are currently used in the majority of anaerobic digesters at livestock farms.
|Induced Blanket Reactor||5|
|Anaerobic Sequencing Batch Reactor||3|
*Plug flow digesters include all modified plug flow digesters (for example, mixed plug flow and horizontal plug flow).
Learn more about the type of anaerobic digesters being used at livestock farms:
- The AgSTAR Anaerobic Digester Database identifies the design features of anaerobic digesters at livestock farms in the United States.
- Stories from the Farm highlight experiences of anaerobic digester operators.
Biogas Facts and Trends
Captured and recovered biogas can be used to generate electricity, to fuel boilers or furnaces, or to create pipeline quality gas or compressed natural gas that can be sold as a vehicle fuel. While a variety of biogas use options are available, collected biogas is most often used to generate electricity and provide combined heat and power (CHP). CHP projects generate electricity and use the excess heat from electricity generation to heat digesters or adjacent buildings.
The line chart below shows trends in the end uses of biogas since 2000. CHP is the most common end use, followed by electricity. The number of CHP and electricity projects steadily increased each year from 2000 to 2013. Since then, the electricity project count has become more stable, while the number of CHP projects continues to rise, albeit more slowly. Boiler and furnace fuel projects have also increased, but at a much slower rate than CHP and electricity projects. Renewable natural gas (RNG) projects, including pipeline injection and compressed natural gas (CNG) for vehicle fuel or other uses, have risen steadily since 2017. Projects that flare the biogas full time currently make up approximately 5 percent of all projects.
|Year||Combined Heat and Power||Electricity||Boiler/Furnace Fuel||Flared Full Time||CNG||Pipeline||Unknown|
- In 2019, anaerobic digesters on livestock farms reduced GHG emissions by 4.63 million metric tons of CO2 equivalent (MMTCO2e).
- 3.84 MMTCO2e direct methane reductions
- 0.79 MMTCO2e emissions avoided
- From 2000 through 2019, anaerobic digesters on livestock farms have reduced direct and indirect emissions by 43.8 MMTCO2e.
- In 2019, energy generation from anaerobic digesters on livestock farms was approximately 1.28 million megawatt-hours (MWh) equivalent.
The chart below shows the amount of direct and indirect GHG emission reductions from anaerobic digesters on livestock farms since 2000. The chart shows a steady increase through 2013 with a total of 4.63 MMTCO2e in 2019.
The following chart shows energy generation from electricity projects and non-electricity projects on livestock farms since 2000. The chart shows a gradual increase from 2000 through 2007 and then a more significant increase from 2008 through 2013. In 2019, AD systems on livestock farms generated the equivalent of approximately 1.28 million MWh of electricity.
(Million kWh/yr Equivalent)
Value of Anaerobic Digester Biogas and Coproducts
State Data and Trends
State Data Sources
- The Database of State Incentives for Renewable Energy (DSIRE) Exit is a comprehensive source of information on state, local, utility and selected federal incentives that promote renewable energy.
- The State Energy Portal Online for Consumers Exit provides a comprehensive view of energy data and information. The tool can help you compare state energy data and rankings, customize maps and charts, and view state rankings of energy production, consumption, prices, and more.
Renewable Portfolio Standards
A state renewable portfolio standard (RPS) encourages or requires utilities to use or buy renewable energy or renewable energy certificates (RECs) to account for a certain portion of their retail electricity sales by a certain date. A REC is a tradable certificate documenting that 1 megawatt-hour of renewable electricity was generated at a specific facility. The goal of an RPS is to stimulate market and technology development so that renewable energy can become more competitive with conventional forms of electric power. A state RPS helps create market demand for renewable energy.
Generally, electricity suppliers can meet the RPS targets by:
- Owning a renewable energy facility and its output generation.
- Purchasing RECs.
- Purchasing electricity from a renewable facility.
Biogas from anaerobic digesters often qualifies as renewable energy under the biomass category of state RPS systems.
Additional information on states with RPS targets is available from the following sources:
- The National Conference of State Legislatures, 2014 update Exit provides state-by-state RPS information.
- The Database of State Incentives for Renewable Energy (DSIRE) Exit summarizes state RPS policies and can help you determine whether and how biogas recovery can meet your state RPS standard.
- Feed-in tariffs (FIT) Exit are a policy tool used to encourage renewable electricity technologies. A FIT program typically guarantees that customers who own a FIT-eligible renewable electricity generation facility will receive a set price from their utility for all of the electricity they generate and provide to the grid.
|Year||Under Construction||Newly Operational||Operational||Shut Down|