When the incumbent joins the insurgent: Former Cummins CEO takes the helm at Mainspring

Tom Linebarger ran Cummins for a decade, capping thirty years at the hundred-year-old power giant. When a leader like that leaves to run a company a fraction of the size, it says something about where electric power is headed. Recently, Mainspring Energy named Tom its new CEO. 

“I’ve spent my career guiding Cummins through multiple technology inflections, and I know what it looks like when a solution is about to become indis­pens­able,” Tom told us. ​“Main­spring’s linear generators are the first technology I’ve seen in thirty years that could actually win — and in a market big enough to matter.” At Cummins, Tom expanded the company into battery-electric powertrains and chaired the global Hydrogen Council. 

The tailwinds behind the company are staggering. Data-center capacity is doubling every two years, manu­fac­turing reshoring is accel­er­ating, and elec­tri­fi­ca­tion keeps pushing loads higher. Meanwhile new grid connections take five to eight years, and large gas turbines are back-ordered to the end of the decade. The country needs more electricity, cleaner and closer to where it’s used, faster than the old playbook can deliver. Main­spring’s generators are available at scale now.

Main­spring’s linear generators have no turbines and no spinning parts. They’re modular, factory-built, and fuel-flexible: they run on natural gas today and can switch to green hydrogen or ammonia as those fuels arrive. Even on natural gas, their efficiency cuts fuel costs and lowers carbon emissions by roughly 30% versus grid power. Deploy now, stay clean later. 

Utilities are the hardest customers in power to win over, and Mainspring is succeeding. The Utah Municipal Power Agency selected Mainspring for a 48-megawatt project in central Utah, a utility-scale asset that will dispatch into the day-ahead market when it comes online in 2027. The modular design keeps capacity running during maintenance, a precision fuel reaction chamber ensures less than 1.5 ppm NOx, and the generators are quiet enough to be sited in urban centers. The result is a world-class system applicable to a wide range of customers.

Shannon Miller built Main­spring’s technology from the ground up and led it as CEO. She now steps into the President role, focused on the operations and customers that define the next phase. She’s also the one who recruited Tom, first to the board and then to the CEO seat. ​“As you scale, you need people who are exceptional at quality, at supply chains, at putting real process in place,” she told us. ​“That’s different from the people who start a company. That’s exactly what Tom brings.”

We couldn’t be more excited to watch them scale the future of flexible power.