Mainspring Energy said on 13 October 2026 that it has signed a sales agreement with American Electric Power (AEP), one of North America’s largest utilities, to supply up to 1.6 gigawatts (GW) of its linear generators through 2034 [1]. AEP has bought a first batch of 190 megawatts (MW), for delivery starting in 2027 [1].
Up to 1.6 GW is a ceiling, not an order
The headline number is a maximum. According to Mainspring’s announcement, the agreement allows for up to 1.6 GW over roughly eight years, but the only firm purchase so far is the 190 MW first tranche, about an eighth of the total [1]. Neither company disclosed a price.
Mainspring calls the deal “the largest procurement of linear generators to date” [1]. That is the company’s own description; there is no independent tally to check it against.
What a linear generator is
Most fuel-burning generators use a flame to drive a spinning shaft. Mainspring’s machine works differently. According to the company, air and gaseous fuel are squeezed until they react without a flame, at a low temperature. That reaction pushes moving parts back and forth in a straight line through copper coils about 13 times a second, and the motion through the coils produces electricity directly [2]. Hence “linear”: the parts slide rather than spin.
Mainspring says the units can switch between natural gas, renewable gas, biogas, propane and hydrogen, ramp up and down quickly, and produce very low nitrogen oxide emissions [2]. They are modular, so a utility can add capacity in blocks close to where it is needed.
What the two sides said
Bill Fehrman, AEP’s chairman, president and chief executive, said the utility continues “to pursue new, innovative solutions to help meet the rapid growth in energy demand”, and that Mainspring’s generators “can provide additional capacity quickly and efficiently” [1].
Tom Linebarger, Mainspring’s chief executive, said AEP is “demonstrating strategic leadership in navigating speed-to-power requirements”, and that linear generators deliver “affordable, reliable, and dispatchable power that works” [1].
The AI data-centre backdrop
Mainspring presents the units as a fast way for utilities to keep up with rising demand from AI data centres, manufacturing and electrification [1]. US utilities face a wave of requests to connect large data centres, and big power plants and grid upgrades take years to build. Smaller generators that can be installed quickly and switched on when needed are one way to fill that gap.
The deal also marks a step up for Mainspring, which says it is moving beyond commercial, industrial and data-centre customers to sell to an investor-owned utility at gigawatt scale. The company says it began shipping in 2020 and now has hundreds of megawatts in development or operation [1].
What this means
- Firm order is 190 MW. The rest of the 1.6 GW depends on future orders through 2034.
- No price. Neither company said what AEP is paying.
- “Largest ever” is Mainspring’s claim. It has not been independently checked.
- Speed is the selling point. Utilities squeezed by AI-driven demand are looking for power they can add in years, not decades.
Sources
- Mainspring Energy via PR Newswire, “Mainspring Energy Signs Landmark 1.6 GW Agreement with AEP for Reliable, Affordable Power Capacity”, 13 October 2026. https://www.prnewswire.com/news-releases/mainspring-energy-signs-landmark-1-6-gw-agreement-with-aep-for-reliable-affordable-power-capacity-302906235.html
- Mainspring Energy, technology page. https://mainspringenergy.com/technology/
