U.S. Gain, a developer and distributor of alternative fuel and renewable energy, has completed its first integration of a solar microgrid at its Dallmann East River Dairy digester in Brillion, Wis.
This U.S. Gain-owned digester has been producing renewable natural gas (RNG) for the transportation industry since August 2020.
This project highlights the integration of sustainability progress and energy independence into the farming and renewable natural gas communities. Using solar panels, renewable electricity is generated and used to power day-to-day digester operations. This electricity can also be stored in onsite batteries to be used at night or on cloudy days.
Additionally, through onsite combined heat and power (CHP) technology, heat is captured and repurposed to reduce natural gas demand.
Producing RNG with renewable energy improves the carbon intensity (CI) of the fuel, making it more sustainable and valuable in the marketplace. Utilizing energy modeling software, the microgrid system was sized to support the needs of the facility and maximize the value of the fuel produced.
Located on nearly four acres of land, the Dallmann digester microgrid is expected to produce 1.9 GWh of electricity annually. This will offset 97% of the Dallmann digester’s electrical energy load that is typically sourced from grid power and will result in renewable natural gas supply with a lower CI score.
Most of the energy being offset is from the solar microgrid, but a significant portion also comes from the CHP technology. Heat byproduct from the CHP electricity generation process is diverted to the digester which reduces boiler heat demands and, consequently, the natural gas used for boiler heating while also feeding backup battery storage.
“This represents the largest project that U.S. Gain currently has to offset our energy use. By collaborating with EnTech, another Wisconsin-based company, we’re able to help drive change right in our own backyard,” says Hardy Sawall, director of business development at U.S. Gain. “Through microgrid integration, we are providing our digester partners with more sustainable infrastructure that translates to lower CI RNG supply and environmental benefits.”
While excess solar energy produced from the Dallmann microgrid can be sold back to the grid, most will be used onsite. The system’s backup battery is able to keep the process operating during power outages. In the future, with appropriate regulatory approvals, this solar microgrid installation could provide Dallmann East River Dairy and U.S. Gain the security of knowing that the dairy and digester would not be impacted by grid outages—preventing data loss, interrupted operations and digester temperature fluctuations.
A key project partner for U.S. Gain’s Dallmann solar microgrid project is EnTech Solutions, a provider of sustainable energy solutions. EnTech Solutions provided end-to-end project management including energy modeling using EnergyDNA, microgrid and solar engineering and development, installation and optimization. EnTech will also provide 24/7 support and maintenance over the 20-year contract. This is the second project that U.S. Gain and EnTech have partnered on for microgrid use at RNG facilities.