U.S. Gain secures new Wisconsin dairy RNG offtake

With the support of leadership from Dane County, Wisconsin (WI), EnTech Solutions, a full-service clean energy solutions provider and a division of Faith Technologies Inc., has partnered with Northern Biogas LLC, a fully-funded renewable natural gas (RNG) producer, in a joint venture to repurpose an anaerobic biodigester facility from power to RNG.

We saw the Middleton project as a great opportunity to leverage our 18-year history of working with anaerobic digesters and nutrient management to support EnTech Solutions in their mission to create sustainable, reliable energy solutions, said Dave Fitch, President of Northern Biogas.

Completed earlier this year, a ribbon-cutting ceremony was held on April 27, 2022, marking the official opening of the repurposed Middleton plant near Springfield that now produces RNG using agricultural waste from approximately 4 000 cows at four local Wisconsin dairy farms.

Partnering with EnTech Solutions, Northern Biogas and our family-owned dairy farms paves the way for home-grown renewable energy, cleaner lakes, and keeping our farm families milking cows for generations to come. This new investment in cutting-edge technology benefits both the local environment and our farm economy while combating climate change, said Dane County Executive Joe Parisi.

Repurposed from power to RNG

Anaerobic digesters (AD) are an integral part of managing manure and organic waste from dairy farms.

The Middleton digester facility had previously produced electricity but has been repurposed to produce RNG that can be easily injected into the natural gas pipeline and distributed throughout the nation.

Together we share a passion for innovation and a commitment to clean energy. Along with the support of Dane County and the local community, we think these new systems and technologies will make a positive impact on the farmers and the surrounding environment, Dave Fitch said.

This facility incorporated advanced technology, including a nutrient concentration system by Aqua Innovations to remove phosphorus that returns clean water to the region’s Yahara Watershed while also reducing phosphorus runoff to nearby streams and lakes.

Our process optimizes nutrient management while decreasing greenhouse gas emissions. We’ve leveraged Northern Biogas’ experience in wastewater treatment and agriculture by working with farmers to improve nutrient separation and utilization from manure and other organic waste while producing a renewable energy product, said Scott Romenesko President of EnTech Solutions.

In 2021, over 27 million (US) gallons (≈ 102,2 million litres) of manure were processed by the biodigester, removing more than 57 000 pounds (≈ 21.2 tonnes) of phosphorus from the watershed.

Water and soil are essential to life on earth, and farmers continue to look for opportunities to improve water quality and soil health. Northern Biogas and EnTech Solutions have opened up high-tech opportunities around dairy manure, working with area farmers to harvest the methane and return the fiber and liquid nutrients back to the farmers for use as organic fertilizer and bedding, maximizing all aspects of the nutrient cycle, said Jeff Endries co-owner of Endres Berryridge Farms.

Integrated microgrid

EnTech Solutions incorporated a renewable energy microgrid at the facility, featuring solar panels and batteries which provide more than 2.8 MW of clean energy generation capacity.

This increases energy efficiency and further reduces the RNG’s CI score. Microgrid use in agricultural applications is still a relatively new concept, but as projects like this come online successfully other digester operations will see it as a viable solution.

The use of microgrids to produce renewable electricity not only saves on project costs but also significantly decreases the facility’s environmental impact by reducing reliance on grid electricity, said Scott Romenesko, President of EnTech Solutions.

This creates a carbon-negative process that results in RNG with a lower carbon intensity (CI) score.

Overall, the facility will reduce emissions by more than 13 500 tonnes per year of carbon dioxide equivalent (CO₂eq).

Using our experience in engineering and energy technologies, we were able to convert the Middleton facility to an even more efficient producer of clean RNG, and accomplished this in a compressed timeframe, Scott Romenesko said.

Offtake with U.S. Gain

U.S. Gain, a division of Wisconsin-based U.S. Venture, Inc., and a leader in the development and distribution of alternative fuel offtakes the RNG and markets it to the transportation sector in California (CA).

The facility’s RNG is trucked to Dane County’s landfill offload station, where it is injected through the county’s equipment into the interstate transmission pipeline to be used as a renewable fuel to power fleets of NGVs.

RNG from cow manure can reduce greenhouse gas emissions (GHG) up to 400 percent when used to replace traditional fossil fuels.

In this case, U.S. Gain is sending RNG from Madison to their fleet customers in California where transportation-related emission reductions are a priority.

We’re proud to work with EnTech Solutions, supplying more carbon-negative RNG to the California market. Manure-based RNG features the lowest carbon intensity scores which translate to the best environmental impact that sustainably-minded organizations are seeking, said Mike Koel, President of U.S. Gain.

He added that given U.S. Gain’s Wisconsin roots, “we’re pleased to see the agricultural community win. Farmers are looking for additional methods to manage their financial needs for future generations and the combination of biodigesters and RNG processing gives them options.”

As businesses continue to become more energy conscious and focus on sustainability goals, RNG paired with the development of microgrids is a great way to decarbonize project operations. We know this is a replicable process that can help other biodigesters achieve their goals, ended Scott Romenesko.