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2022 Minnesota Renewable Energy Roundtable Explores the Promise of Renewable Natural Gas Produced from Anaerobic Digestion

Late last year, a group of scientists, researchers, academics and business leaders discussed the latest advancements and innovations in renewable natural gas and anaerobic digestion at the 2022 Minnesota Renewable Energy Roundtable (RER).

For those who are unfamiliar with the topic, anaerobic digestion is the controlled use of biodegradable organic materials to produce renewable energy in the form of biogas and fertilizer. It is an ancient technology and a naturally occurring biological process during which consortia of bacteria decompose organic matter in the absence of oxygen to obtain the energy necessary for their metabolism.

The Agricultural Utilization Research Institute (AURI) hosted the 2022 RER event in Waseca, Minn. In addition to the presentations from experts, the roundtable event also included a tour of AURI’s anaerobic digester at its Waseca Coproducts Pilot lab.

“There is so much activity going on in Minnesota in anaerobic digestion right now, more than many of us realize,” said Shannon Schlecht, executive director of AURI. “The benefit of an event like the Renewable Energy Roundtable is we bring the right group of people together to learn more about what is happening. How are different developers and companies looking at using biomass feedstocks? What are the state and federal policies and incentives available? Working together across the value chain, we can have meaningful discussions about how to make these projects viable going forward.”

There are numerous industrial applications as well as economic and environmental benefits for the Upper Midwest’s agricultural sector. There has been significant growth in biogas in recent years across the United States. According to the American Biogas Council, Minnesota ranks eighth out of 50 states for biogas potential.

“The potential is massive,” said Dr. Luca Zullo, AURI’s senior director of science and technology. He estimated there are about 2,000 sites in the U.S. that produce biogas using anaerobic digestion and the vast majority are at municipal wastewater treatment facilities. He said experts identified an additional 8,000 sites for agriculture, 2,000 sites for food waste and 15,000 sites for biogas generation across the country. There is work needed to build out the potential, but it is possible to achieve real results, Zullo stated.

Targeted growth and development of this technology will benefit agriculture and the entire regional economy through increased investment and more jobs. Recent global developments underscore the importance of producing energy closer to home that is immune to market shocks and geopolitics.

Venus Welch-White is the U.S. Environmental Protection Agency’s (EPA) Senior Advisor to the Administrator’s Agriculture Advisor. She was one of the presenters at the roundtable event and said the EPA has significant interest in this space and cited many examples of how the federal government is working to advance the adoption and expansion of renewable gas produced by anaerobic digestion.

There is a voluntary program co-administered by the EPA and the U.S. Department of Agriculture to advance sustainable manure management practices in agriculture. There are also federal efforts and incentives underway to reduce methane emissions in landfills and to reduce food loss and food waste.

Further, President Biden’s administration signed executive orders that address methane emissions reduction and the catalyzation of climate-smart technologies to address the climate change crisis. Meeting the goals outlined in both executive orders will include significant input from the anaerobic digestion space, Welch-White said.

“The EPA supports voluntary incentives rather than using a regulatory hammer,” Welch-White said. “Anaerobic digestion plays a significant role in all of this work as we look to address these priorities.”

Megan Lennon, the Energy and Environment Section Supervisor- Ag Marketing and Development Division for the Minnesota Department of Agriculture, outlined many of the policies and incentives from the state of Minnesota that deal with anaerobic digestion and renewable natural gas. Lennon said several factors are encouraging further innovation and growth in anaerobic digestion. In addition to the federal government, Minnesota set several goals to reduce greenhouse gas and carbon emissions as part of the state’s Climate Action Framework. Private industry in the U.S. has also identified sustainability goals and targets. Further, there has been an injection of capital investment into the sector with the potential to kick-start renewable gas adoption and usage, especially on the west coast of the United States. There are a few facilities in Minnesota that are already producing biogas and adding it into the energy pipeline to earn credit in California’s low carbon fuel market, Lennon said.

“When these factors align, renewable natural gas and anaerobic digestion is elevated to the forefront and seen as a key solution to meeting various climate change goals,” Lennon said. “[Anaerobic digestion] is also part of a solution for a variety of different sectors, not just agriculture, which is hard to decarbonize. I really believe the deployment of [anaerobic digestion] is going to increase in the short term.”

Emma Ingebretsen is the Senior Project Manager for Decarbonization Projects at CenterPoint Energy. The utility company is working to reduce carbon emissions both for its customers and its operations. CenterPoint Energy set goals to achieve Net Zero emissions from its operations and facilities by 2035 and to reduce emissions from the natural gas usage of its residential and commercial customers by 20 to 30 percent by 2035 (from a 2021 baseline).

One tool CenterPoint will use to achieve those benchmarks is the Natural Gas Innovation Act, a new law allowing the utility to invest further in innovative clean energy resources and technologies to reduce emissions, including green hydrogen and renewable natural gas.

Biogas and renewable natural gas made using anaerobic digestion has significant potential to play a key role in reducing the carbon intensity of the energy the utility delivers to customers, Ingebretsen said. Further, made-in-Minnesota energy like renewable natural gas can further support job creation and economic development, while also diversifying CenterPoint’s own energy supply.

CenterPoint is developing an innovation plan to submit to the Minnesota Public Utilities Commission (PUC) for consideration and review. The expansion of biogas and the addition of new anaerobic digesters are among the pilot project concepts that CenterPoint is vetting for consideration to be included in the final text. If the PUC approves CenterPoint’s plan, the utility company can recover some of the cost of implementation of the new strategies and tools.

“As we prepare our first innovation plan for regulatory review under the Natural Gas Innovation Act, we are definitely exploring the possibility of sourcing made-in-Minnesota [renewable natural gas] and supporting anaerobic digester projects from a variety of feedstocks,” Ingebretsen said. “We are developing a portfolio of projects, including biogas and renewable natural gas, to include in our first innovation plan that we expect to submit to the Minnesota Public Utilities Commission in the first half of 2023.”

The National Renewable Energy Laboratory (NREL) is a national laboratory focused on finding creative answers to today’s energy challenges. Dr. Kevin Harrison is the Program Manager for NREL’s Energy Systems Integration Facility. In that role, he supports several near-commercial research and development projects, including renewable hydrogen production, systems integration and renewable natural gas production via biomethanation. Harrison works to identify high-impact research capabilities and develop strategic partnerships with industry leaders.

He spoke about the importance of events like the Minnesota Renewable Energy Roundtable and the potential for the Upper Midwest and Minnesota to become a leader in the field of biogas and anaerobic digestion.

The state has a lot of opportunities in the agriculture sector obviously, there is also high potential in the culture of Minnesota being progressive enough to not only consider hydrogen production but also really exploring turning waste back into energy,” he said. “When you have farmers, the university, industry support groups, utilities and developers all in the same room, you get a great section of ideas and diverse questions.”

Harrison said he feels a great sense of urgency centered around creating hydrogen gas from renewable molecules. The NREL exists to help businesses, governments and research centers refine and improve the technologies to drive down costs. He said industry estimates the return on investment in this field is $6 to $8 returned for every $1 invested.

“The next step is to create a team where we can deploy and demonstrate the value here and teach the next generation of famers, researchers and scientists how to decarbonize utilizing energy created from waste,” he said.

Thom Petersen, Commissioner of the Minnesota Department of Agriculture, attended the Minnesota Renewable Energy Roundtable. He said the innovations and advancements discussed play a crucial role in Minnesota’s energy and economic future.

“The Department of Agriculture is very interested in the work being done in this field,” he said. An idea like manure digestion has been around for a while and our gains have been slow, but there is certainly a renewed interest in the technology now. We are seeing similar excitement for digestion in food and commercial waste. Discussions like the Renewable Energy Roundtable are very helpful in terms of getting a sense of the landscape and then really pinpointing opportunities where we can make progress.”

If you’d like to learn more from the Renewable Energy Roundtable event, visit YouTube to watch a recording of the event.