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AgSTAR

AgSTAR Data and Trends

There are 263 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.

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.

Market Opportunities for Biogas Recovery Systems at U.S. Livestock FacilitiesMarket Opportunities for Biogas Recovery Systems at U.S. Livestock Facilities assesses the market potential for biogas energy projects at dairy and hog farms in the United States.

Challenges and Opportunities for California's Dairy Economy​Challenges and Opportunities for California’s Dairy Economy Exit explores the potential of dairy biogas systems to reduce environmental impacts while generating energy and/or income for dairies.

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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). In addition to the 6 systems that have come online so far this year, another 19 are under construction.

 

Year Operational1 Newly Operational2 Shut Down
2020* 263 6 0
2019 258 14 3
2018 247 12 2
2017 237 8 4
2016 233 4 9
2015 238 8 5
2014 235 9 5
2013 233 30 3
2012 205 30 1
2011 176 26 9
2010 160 18 3
2009 142 24 15
2008 133 34 7
2007 106 18 3
2006 91 21 2
2005 72 15 2
2004 59 18 2
2003 44 7 1
2002 39 10 1
2001 31 6 0
2000 25 1 0

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.

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.

 

System Type Count
Plug Flow* 97
Complete Mix 87
Covered Lagoon 64
Induced Blanket Reactor 5
Anaerobic Sequencing Batch Reactor 3
Fixed Film 2
Dry Digester 1
Other/Unknown 4

Learn more about the type of anaerobic digesters being used at livestock farms:

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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 projects steadily increased each year from 2000 to 2015, and then began to slightly decline.
  • The number of electricity projects steadily increased each year from 2000 to 2013. Since then, the electricity project count has become more stable.
  • The number of boiler and furnace fuel projects increased much more slowly from 2000 to 2013 and has seen little change since.
  • Renewable natural gas (RNG) projects, including pipeline injection and compressed natural gas (CNG) for vehicle fuel or other uses, have risen steadily and significantly since 2017.
  • Projects that flare the biogas full time currently make up approximately 4 percent of all projects.
 

Year Combined Heat and Power Electricity Boiler/Furnace Fuel Flared Full Time CNG Pipeline Unknown
2020 121 86 13 12 25 15 1
2019 123 88 13 13 22 8 1
2018 124 85 13 13 11 4 1
2017 124 82 13 13 3 3 1
2016 125 79 13 13 3 1 1
2015 127 80 13 13 4 1 3
2014 123 80 13 14 4 0 4
2013 120 83 12 13 5 0 4
2012 106 69 12 13 4 1 3
2011 95 52 11 15 3 1 1
2010 87 44 13 15 5 1 0
2009 78 36 11 15 2 2 0
2008 74 33 11 11 2 4 0
2007 66 21 11 6 0 1 1
2006 51 21 11 6 0 1 1
2005 37 20 9 4 0 1 1
2004 28 19 8 2 0 1 1
2003 21 13 7 2 0 0 1
2002 18 10 8 2 0 0 1
2001 13 9 6 2 0 0 1
2000 11 7 4 2 0 0 1

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Environmental Benefits

  • In calendar year 2019, anaerobic digesters on livestock farms reduced GHG emissions by 4.65 million metric tons of CO2 equivalent (MMTCO2e).
    • 3.85 MMTCO2e direct methane reductions
    • 0.80 MMTCO2e emissions avoided
  • From 2000 through 2019, anaerobic digesters on livestock farms have reduced direct and indirect emissions by 41.7 MMTCO2e.
  • A projected reduction in direct and indirect emissions of 4.81 MMTCO2e is expected from anaerobic digesters on livestock farms in calendar year 2020.
  • In 2019, energy generation from anaerobic digesters on livestock farms was approximately 1.35 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 projected total of 4.81 MMTCO2e in 2020. The increase in direct reductions in recent years is driven in large part by the uptick in RNG projects coming online since 2017.

 

Year Direct Reductions
(MMTCO2e)
Indirect Reductions
(MMTCO2e)
2020 4.015147093 0.798305497
2019 3.846127428 0.800906690
2018 3.219751498 0.731445623
2017 2.888268950 0.715805603
2016 2.846746854 0.752973002
2015 2.772753582 0.766039430
2014 2.941098409 0.764863794
2013 2.897157217 0.726801630
2012 2.304410917 0.591086410
2011 1.890832274 0.439924941
2010 1.663142262 0.379223679
2009 1.484863516 0.316670458
2008 1.370641685 0.274970808
2007 0.941009528 0.163629926
2006 0.854999875 0.115765995
2005 0.616585375 0.084386673
2004 0.454869893 0.064024840
2003 0.324474919 0.047273093
2002 0.275149123 0.039121338
2001 0.227956086 0.029423847
2000 0.101779040 0.012581513

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 2020, AD systems on livestock farms are expected to generate the equivalent of approximately 1.41 million MWh of electricity.

 

Year Electricity Projects
(Million kWh/yr)
Non-Electricity Projects
(Million kWh/yr Equivalent)
2020 972.1 435.8
2019 1001.4 349.4
2018 978.3 71.5
2017 934.8 39.1
2016 942.3 19.3
2015 959.1 3.7
2014 974.3 3.7
2013 939.4 3.7
2012 714.4 57.2
2011 505.3 56.9
2010 437.2 57.3
2009 348.2 81.3
2008 290.8 97.6
2007 154.4 19.5
2006 118.0 19.5
2005 75.3 17.3
2004 64.0 17.3
2003 44.5 0.7
2002 31.1 0.2
2001 20.9 0.2
2000 17.6 0.2

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Value of Anaerobic Digester Biogas and Coproducts

The Innovation Center for U.S. Dairy Exit provides information about production possibilities and market values of the products from mature anaerobic digesters.

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State Data and Trends

State Data Sources

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:

Feed-in Tariffs

  • 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.

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Year Under Construction Newly Operational Operational Shut Down
2020 19 6 257 0
2019 0 14 244 -3
2018 0 12 235 -2
2017 0 8 229 -4
2016 0 4 229 -9
2015 0 8 230 -5
2014 0 9 226 -5
2013 0 30 203 -3
2012 0 30 175 -1
2011 0 26 150 -9
2010 0 18 142 -3
2009 0 24 118 -15
2008 0 34 99 -7
2007 0 18 88 -3
2006 0 21 70 -2
2005 0 15 57 -2
2004 0 18 41 -2
2003 0 7 37 -1
2002 0 10 29 -1
2001 0 6 25 0
2000 0 1 24 0