Mainspring Appoints Former Cummins Chairman and CEO Tom Linebarger as CEO and Founder Shannon Miller as President to Power Next Wave of Growth

Leadership addition fuels company expansion into AI Data Center and Utility Power Infrastructure Markets

MENLO PARK, Calif., June 10, 2026 /PRNewswire/ -- Shannon Miller, the founding CEO of Mainspring Energy, has spent fifteen years reinventing the way the world turns fuel into electricity. Mainspring's linear generators are fuel-flexible, highly efficient, and low-emissions, making them uniquely suited to meet today's unprecedented demand for power, driven by the race for AI dominance, the global transition to electrification, and the rise of onshore manufacturing. Electric utilities, data centers, and commercial companies share the need for power that is reliable, affordable, and fast to deploy. Mainspring delivers all three to a growing list of blue-chip customers across the U.S.

Miller led the successful development, launch and commercialization of Mainspring's product line since co-founding the company in 2010. Fourteen months ago, Tom Linebarger joined the company's board of directors. After working closely with him, seeing the impact he could have and the scale and speed of growth ahead, she initiated and recruited him to join the senior leadership team.

Today, Mainspring announced that Linebarger, former Chairman and CEO of Cummins, Inc. and current Chairman of Mainspring, will take the role of Mainspring CEO. At Cummins, he spent 30 years navigating an energy company through tremendous growth and entry into new markets. That is exactly the experience this moment demands. Mainspring is expanding rapidly into utility and AI data center markets, and Tom has spent his career at that intersection.

"I am deeply proud of the progress Mainspring is making in our mission of unlocking global access to low-carbon, dispatchable energy," said Miller. "We have developed, launched, and commercialized our technology and we've expanded our field operations across many parts of the U.S. with hundreds of megawatts in advanced development and field operations. Our products are delivering reliable, cost-effective, low emissions power to customers every day."

Having worked with Linebarger for 14 months as a board member, Miller added, "I firmly believe that Tom Linebarger is the ideal CEO for Mainspring as we move into our next phase of growth. He brings decades of hands-on power industry leadership and an outstanding record of smart strategic decisions."

"Beyond that, Tom exemplifies our company's core values. We work exceptionally well together, and I have long valued his counsel. I look forward to the opportunity to work even more closely together while also being able to engage more deeply and directly in many of the key operations of the company."

"Mainspring has built something truly exceptional," said Linebarger. "Under Shannon's leadership, the company has developed a differentiated power generation technology, assembled a world-class team, and established strong momentum with leading commercial, industrial, utility, and data center customers. The global market for power infrastructure is at an inflection point, and Mainspring is ideally positioned to serve this need with its modern, flexible, modular power generation solutions. I am excited to work alongside Shannon and the entire Mainspring team to help accelerate the company's growth and expand its impact."

Over his 30 year career at global power technology leader Cummins, Inc., Linebarger led the successful growth strategy for the company's flagship engine products while expanding into battery electric powertrains and moving into the data center power industry. He also created a leadership program that trained 150 Cummins executives in business acumen and emotional intelligence. Outside Cummins, Linebarger chaired the Hydrogen Council, a global CEO-led group advancing a sustainable hydrogen economy. Most recently he served as a senior advisor and entrepreneur in residence focused on energy at General Catalyst, a venture capital and investment company. He joined General Catalyst in January 2025 after serving as a senior advisor for McKinsey and Company following his retirement from Cummins Inc in 2023. In addition to his current role as chair of the board of directors at Mainspring, Linebarger is a member of the board of directors of Republic Services. He was formerly lead director of the board of directors at Harley-Davidson, Inc. and served on the board of directors of the Business Roundtable.

About Mainspring
Mainspring Energy manufactures and delivers fuel-flexible, low-emissions local power solutions that rapidly add new capacity and deliver reliable, affordable, and sustainable electric power. 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 also partners with global energy leaders including AEP, NextEra Energy Resources, Schneider Electric, and more. Learn more at mainspringenergy.com.

SOURCE Mainspring Energy, Inc.