In conversation: New Mainspring CEO Tom Linebarger & President Shannon Miller.

Mainspring's next stage: Powering the AI Era

Shannon Miller started Mainspring Energy with a vision and a prototype for a modern power generator that would be ideally suited to solve the toughest power problems while also adapting to a changing power infrastructure over time. The electricity grid was already aging and needed lower cost, lower emissions solutions that would also improve reliability. It was also clear that flexibility and adaptability would be a critical asset as needs were changing. 

That’s why Mainspring has spent the last 15 years developing and commercializing a new kind of power generator that can deploy locally, run on virtually any fuel, and deliver reliable low-emission power without depending on a grid connection that might take years to arrive. As AI data centers strain the grid and utilities scramble to keep up, that capability has become one of the most sought-after in the energy industry. We sat down with Mainspring President and Founder Shannon Miller and incoming CEO Tom Linebarger to talk about linear generators, the critical need for reliable, low cost, local power , and where they are taking the company next.

"Shannon, you have been building Mainspring for fifteen years. Why does this moment feel different?"

Shannon: When I started this company I was a mechanical engineer who believed there was a fundamentally better way to generate power. The grid was designed for a different era and I could see that the world was going to outgrow it. What I did not anticipate was how fast that would happen or what would drive it. The AI buildout has created a power crisis that is very real and very immediate. These companies are not waiting around. They are trying to build as fast as they possibly can and the thing stopping them is not money or talent or ambition. It is power. That is the problem we have been working on for fifteen years, and the reason our customers call us is because we actually solve it.

"What does solving it actually look like?"

Shannon: It looks like showing up when the grid cannot. A customer needs power for a data center and the grid cannot get there for three years. We can be there in months. Our generator runs on virtually any fuel, it does not need a grid connection to operate, and it delivers reliable clean power from day one. We started shipping commercially in 2020 and today we have hundreds of megawatts in field operations and advanced development with some of the largest companies and utilities in the country. These are serious organizations with serious power needs and they chose Mainspring because we delivered on what we said we would do.

"Tom, you spent thirty years building Cummins into a global energy company. What made you want to join Mainspring?"

Tom: What Shannon has built here is one of the most impressive companies I have encountered in my career. A genuinely new machine architecture that is better by design, proven in commercial operation, with a customer base that depends on it every day. Most companies at this stage have a product that works in controlled conditions or a handful of pilot projects. Mainspring has real megawatts in the ground with customers, running their operations every day. When I looked at that and then looked at where the market was heading, the decision was straightforward. I have spent my career at moments where the energy industry had to change and I know what it looks like when a technology is ready to scale. Mainspring is at that point right now.

"How do linear generators differ from other new power generation technologies you have seen in recent years?"

Tom: I have looked at dozens of new designs for generators of all kinds, and while many of them offer some advantages, their disadvantages limit them from beating existing technologies.   Mainspring's linear generator is the first in my entire career that I believe offers meaningful advantages over existing technologies across multiple dimensions. Moreover, Shannon and team have already tested it in some of the most difficult environments. It’s field-proven today with customers. This is a tremendous advantage.

"How big is the market you are going after?"

Tom: Many data centers being built for AI need what Mainspring provides. Utilities trying to meet demand that is growing faster than the grid can handle need flexible generation that can deploy quickly and cleanly. Companies trying to meet their clean energy commitments need something that works today, not in a decade. We are not waiting for some future version of the grid to make our product relevant. The need is here right now and it is growing faster than most people anticipated. I have watched a lot of markets develop over thirty years and I have rarely seen a situation where demand is this urgent and supply this constrained, and where a company is as well positioned as Mainspring to help meet it.

"Shannon, you recruited Tom specifically for this role. What does having him here change?"

Shannon: Tom has spent his career doing exactly what Mainspring needs to do next, which is take a proven energy technology and scale it across a market that is ready for it. He has the relationships, the experience, and the credibility that comes from having actually done this before at very large scale. What that gives me is the ability to focus on what I care most deeply about, which is building the best product and making sure we execute well for every customer we serve. I spent fifteen years proving this works. Now we get to prove how big it can get, and I think there is significant opportunity ahead for this company.

"Where will Mainspring be in five years?"

Tom: The companies that solve the power problem over the next decade are going to play an important role in a major infrastructure build. AI, clean energy, grid modernization, the reshoring of American manufacturing. All of it runs on power and all of it needs more than the grid can currently deliver on its own. Mainspring is working to be one of the companies that helps close that gap at scale.

Shannon: We have the product. We have the customers. We have the team and we have a market that is growing faster than we expected when we started. I founded this company because I believed we could build something that actually changed how the world generates power. Fifteen years in, with everything we have proven and everything that is now in front of us, I believe that more than ever. We are just getting started.

Shannon Miller is the President and Founder and Tom Linebarger is Chairman and CEO of Mainspring Energy.