In the United States (US), Chattanooga’s Moccasin Bend Environmental Campus (MBEC) is launching a project that will generate electricity from wastewater methane, a move expected to significantly reduce the campus’s roughly US$300,000 monthly energy costs while turning a treatment byproduct into a reliable on-site energy source.
The Mainspring Linear Generator system will allow MBEC to produce much of its electricity on-site, offsetting about one-third of its electric bill and eliminating routine methane flaring.
Generating power at the campus will also strengthen grid reliability by reducing dependence on outside electricity during periods of high demand or disruption.
Once fully operational at 3 MW, the installation will rank among the largest municipal biogas-to-power projects in the Southeast and represents a step toward stabilizing long-term energy costs for ratepayers while advancing Chattanooga’s broader sustainability goals.
MBEC selected Mainspring Energy to install six linear generators this year, producing an initial 1.5 MW of electricity using methane (aka sewage gas) captured during the wastewater treatment process.
Six additional generators are planned following campus upgrades, doubling total generating capacity.
Fuel flexible
The generators operate using a low-emission engine capable of running on biogas, fossil gas, hydrogen, or ammonia, allowing MBEC to adapt to evolving fuel sources while maintaining continuous power generation and reducing greenhouse gas emissions.
This project changes how we think about wastewater treatment. Instead of treating methane as waste, we’re using it to power essential operations, strengthen reliability, and lower long-term energy costs for the community we serve, said Mark Heinzer, administrator of MBEC.
Adam Simpson, chief commercial officer and co-founder of Mainspring Energy, said the partnership reflects a growing focus among municipalities on improving infrastructure resilience while reducing emissions.
We’re proud to partner with the City of Chattanooga on a project that reflects forward-looking leadership and a practical commitment to strengthening critical infrastructure. They were seeking a solution that could be deployed quickly, operate on multiple fuel types at low emissions, and provide dependable on-site power to convert waste into a productive energy asset. We are able to deliver all of that and more, and we look forward to continuing to expand this project with them over time, Adam Simpson said.

