‘We have a tremendous story to tell’: Dairy farmers praise on-farm digesters

A panel of experienced dairy farmers share insights about the opportunities that come with operating on-farm digesters at Biogas Americas 2024.
Courtesy of Biogas Americas 2024/American Biogas Council

Some common themes emerged when a panel of experienced dairy farmers from across the country gathered recently at Biogas Americas 2024 to share anecdotes and insights about the challenges and opportunities that come with operating on-farm digesters.

“It’s a remarkable opportunity to have four farmers share stories of how they’ve evolved in an industry that’s rapidly growing,” Iowa dairy farmer Bryan Sievers told the audience gathered for a Biogas Americas 2024 panel entitled “Fueling Farms: Biogas from the Farmers’ Perspectives”.

“These folks are pioneers and have a deep passion for what they’ve been able to do over the years.”

For four decades, Sievers has operated a farm in eastern Iowa that’s been in his family since 1851. The farm’s digesters have been producing electricity for the grid since 2013 with plans underway to start producing renewable natural gas.

“We focus on a circular approach to our farming operation,” he explained.

“A waste product of one end of our business becomes a feedstock for the next stage.”

A ‘game changer’ for soil health

The digestate produced by the digesters as a byproduct is used as fertilizer on over 2,000 acres, displacing the need for synthetic fertilizers and increasing soil organic matter by 50 percent, Sievers added.

In the decade since Sievers started operating the digester, soil organic matter has jumped from 3.5 percent to 5 percent.

“When you start to realize the impact that using digestate can have on your soil health…that’s a game changer,” he said.

Sievers also emphasized the importance of communicating the “pay it forward” story to anyone who may not be supportive of anaerobic digestion or modern agriculture.

“We’re trying to improve the quality of life not only for our families, but for the people that work for us, the people that live in our communities, but also the soil, the air, and the water.”

Steve Shehady, a third-generation dairy farmer from Bar20 Dairy in California, told the story of how a small bottling plant started by his grandfather in the 1940s evolved into a sprawling dairy operation with more than 7,000 cows today.

“We’ve been committed to sustainability for the last 20 years,” he said of Bar20 Dairy, sometimes referred to as California’s “most sustainable dairy”.

“For us, a digester made sense.”

From manure to electricity or hydrogen fuel

The dairy has had an operational digester since 2021, which helps power an electric feed mixer. The biogas that’s captured and cleaned goes into a one-megawatt fuel cell that produces about 8 million kilowatt hours of power annually, enough to power 177,000 electric BMWs for a year, according to Shehady.

The surplus biogas produced by the on-farm digester is converted to hydrogen transportation fuel that powers buses in the nearby city of Fresno.

Bill Kilby, an on-farm digester pioneer from Maryland boasted that his digester produces about two million kWh of electricity a year, more than twice what he needs to power his farm.

“The rest goes to the grid, which is enough electricity for about 190 houses. We also remove 20,000 tons of carbon a year, which is like removing 4,000 vehicles from the road,” he added, referencing findings from a recent University of Maryland audit of his farm’s system.

The University of Maryland also served as an early advocate of Killby’s ambition to build a digester on the farm to help get the project off the ground.

“It wouldn’t have been possible to do what we wanted without their support. At the time, very few people were willing to develop a methane digester on a farm that uses flush water and sand for bedding,” he explained.

‘Community as partners’ in on-farm digester projects

With more than 1,000 cows located in a suburban part of Maryland, Killby has always needed to think about how the local community perceived his operation,

“We’ve always had to consider the community in everything we do,” he said.

Installing the digester was another step in Killby’s wider effort to demonstrate to his neighbors that the family dairy tried to “recycle almost everything”.

“We had this concept to address the community as partners and it seems to have worked,” he added.

Mark Stoermann from Newtrient – a company dedicated to reducing the U.S. dairy industry’s environmental footprint in an economically viable way – shared the story of his journey in the dairy industry started on his uncle’s 40-cow dairy operation in rural Minnesota.

He highlighted the importance of digesters to California’s efforts to reduce emissions from the state’s sizeable agricultural sector, where digesters have already cut emissions by 21.8 million metric tons, according to recent figures from the California Air Resources Board (CARB) 2024 annual report on climate investments.

California’s on-farm digester success story

According to the report, California’s Dairy Digester Research and Development Program only used around 1.8 percent of the roughly $11 billion spent in the last decade through the California Climate Investments programs. Anaerobic digesters produced 20 percent of the 109 million metric-ton emissions reductions achieved by the program so far, making it one of the largest single contributors to emissions reductions.

“The cost per metric ton is less than $10,” Stoermann added, emphasizing the impact of anaerobic digesters on California’s emissions.

“It’s one of the lowest costs per metric ton of any technology or program.”

In addition, digesters brought $2.10 into California for every dollar spent through the program, according to CARB data.

“It’s truly a story of how dairies can be a solution to a problem and part of the solution to many problems,” he said.

“The impact [digesters] have made in California is a demonstration of the impact we can make as an industry across the country.”.

Sievers explained that the ABC was “committed to doing more to communicate the message to communities that these (digesters) are good for your community”.

More resources for communication

To illustrate the importance of communicating on-farm digesters’ benefits to local communities, Sievers shared the story of how a “fear campaign” by opponents of modern meat and milk production led one community to reject authorizing the construction of a new digester.

“They basically thought it was like building a nuclear waste dump in their community,” he said.

The campaign prevented the community from deriving the benefits of anaerobic digestion of manure, something Sievers described as “frustrating”.

He advocated for devoting more resources to helping local communities better understand the benefits that on-farm digesters can bring in terms of investment and jobs, better waste management, reduced odors, and improved soil and water quality.

Moderator Melissa VanOrnum from DVO lamented that on-farm digesters often “get caught in the crosshairs” by groups willing to brush aside the very real and proven climate benefits of digesters rather than embrace them.

“We have a tremendous story to tell,” she said.

“Hopefully more people will start to understand the benefits our technology can provide, not just to farmers but the communities surrounding them.”