Wisconson Municipality Using Waste Gas to Power Microturbines at Sewer Plant
Gas-fired microgrids are increasingly powering mission critical water and sewer operations in towns and cities throughout the U.S.
The city of Janesville, Wisconsin, is powering its wastewater treatment operations with on-site power featuring new biofuel-fired microturbines from Capstone Green Energy.
Capstone distributor Vergent Power is handling the order from the city of Janesville. The municipality has purchased two additional C65 microturbines, one C200S microturbine, and a Vergent controller.
While two C65 microturbines from the original 2010 installation are operational, the follow-on project includes the commissioning of a C200 microturbine in November 2024, as well as the recent commissioning of two C65 microturbines in April 2025. The orders will increase the facility's total on-site generation capacity to 460 kW.
“Our facility is operating a new microturbine at a fraction of the cost,” said David Botts, P.E., Utility Director for the City of Janesville, in a statement. “Vergent has been excellent at handling the upgrade for us, with minimal involvement from our team. Having access to so many external funding programs allows us the ability to lower our carbon footprint on a sustainable basis for our community. The process could not have been more seamless. All wastewater treatment facilities should explore similar opportunities to improve their efficiency, all while reducing costs.”
The new microturbines will operate in a combined heat and power (CHP) application, utilizing digester gas as the fuel. The waste heat from the microturbines will be captured and converted into thermal energy for the facility's anaerobic digesters.
The approach will help reduce greenhouse gas emissions, while lowering operational costs. Many municipal wastewater systems are turning to on-site power and microgrids to ensure resilience even in the event of outages. Some of those waste and wastewater treatment microgrids included projects in the city of Camarillo, California, Sacramento, Houston and the District of Columbia.
The decision to expand their Capstone microturbine system was driven by Janesville’s positive experience with the reliability and performance of Capstone’s technology. The availability of financial incentives, including the federal Investment Tax Credit (ITC) and a Department of Energy (DOE) ITAC grant, which covered 90 percent of project costs, helped support the City’s goal to upgrade its energy infrastructure using Capstone solutions.
