Project expected to reduce energy costs, strengthen grid reliability and cut methane emissions

CHATTANOOGA, Tenn., and MENLO PARK, Calif., March 9, 2026 — 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 on-site energy source.     

The Mainspring 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 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 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.”

About Moccasin Bend Environmental Campus
The Moccasin Bend Environmental Campus is the largest wastewater treatment campus in southeast Tennessee. MBEC has a treatment capacity of 230 million gallons per day and processes an average of 65 million gallons daily, serving more than 400,000 residents across six counties and two states.     

MBEC focuses on infrastructure modernization, energy efficiency and long-term environmental compliance and plays a key role in protecting public health and the Tennessee River ecosystem.

About Mainspring 
Mainspring Energy manufactures fuel-flexible, low-emissions local power solutions that rapidly add capacity and deliver reliable, affordable and sustainable electricity. The company began commercial shipments of its Mainspring Linear Generators in 2020 and today has hundreds of megawatts in advanced development and field operations for leading Fortune 500 companies, data centers and utilities. Mainspring partners with global energy companies including AEP, NextEra Energy Resources, Schneider Electric, and more.