Carbon Capture at Dairy Farms Seeing Unprecedented Growth

WASHINGTON — The number of dairy farms relying on biogas capture systems to “green” their operations has doubled over the past five years, according to a new report from the American Biogas Council.

The data, released to coincide with National Dairy Month, shows that there are currently 471 biogas capture systems in operation on dairy farms across the United States.

At the same time, the data suggests that the nature of carbon capture is changing.

At the end of 2020, tank-based digesters represented 24% of all anaerobic digestion facilities, with covered lagoons representing the remaining 76%. Fast forward to today and covered lagoons now account for 43% of all facilities.

The end-use of the captured biogas has also seen a major shift over this period. 

Of the 471 systems today, 60% are now upgrading biogas to renewable natural gas, with the remaining 40% using the biogas to produce electricity or heat. 

By contrast, at the end of 2020, 74% of the biogas captured was used for power generation, while just 26% of all U.S. dairy biogas capture systems were producing RNG.

While reducing methane emissions and creating renewable energy, the 471 dairy biogas capture systems in operation today also recycle the manure from approximately 2.3 million dairy cows and produce natural fertilizer and animal bedding, in addition to reducing odors.

Biogas capture from dairy manure has increased by 130% since 2020, now standing at 144,454 cubic feet per minute. In energy terms, this represents a capacity of 47.2 million MMBtu — enough to power 615,000 homes each year and equivalent to preventing nearly 1 million tons of methane entering the atmosphere every year.

According to the American Biogas Council, almost $3 billion has been invested on U.S. dairy farms since 2020 to capture the biogas from their manure. 

Dairy-based biogas facilities opening in 2024 represented investments of $1.1 billion in that year alone, the organization said.

Still, based on the latest data, so much more can be done.

Looking only at the dairy farms with 500 cows or more, an additional 2,980 farms have the potential to become part of the trend and join the 471 facilities already operational. 

In total, the council said, just 14% of all potential dairy biogas facilities in the U.S. have been built.

Wisconsin has the highest potential for new dairy biogas capture systems, with 561 possible sites that could be added to the 54 currently operating. Over a third of operational systems in the U.S. are located in California, which still has the potential for developing a further 543.

Dan can be reached at [email protected] and @DanMcCue