Chattanooga's Moccasin Bend Environmental Campus is launching a project that will generate electricity from wastewater methane, a move expected to significantly reduce the campus's roughly $300,000 monthly energy costs while turning a treatment byproduct into a reliable onsite energy source.   

The Mainspring system will allow MBEC to produce much of its electricity onsite, 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 three megawatts, 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 megawatts of electricity using methane captured during wastewater treatment processes. Six additional generators are planned following campus upgrades, doubling total generating capacity.

The generators operate using a low-emission engine capable of running on biogas, natural 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," said Mark Heinzer, administrator of MBEC. "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."   

Adam Simpson, chief commercial officer and co-founder of Mainspring, 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," Simpson said.  "They were seeking a solution that could be deployed quickly, operate on multiple fuel types at low emissions, and provide dependable onsite 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."