Hyliion proves power generation is at its Core

Hyliion didn’t start out specializing in power generation. Rather, the Texas-based company – whose name combines “Hybrid + Lithium + Ion” – was founded in 2015 by now-CEO Thomas Healy, centered around hybrid electric drivetrains for Class 8 trucks. It was only several years later that energy solutions became the company’s primary focus.

Thomas Healy, CEO, Hyliion. (Photo: Becky Schultz)

“A couple of years ago, we were here at this show, and we saw a change happening in the industry,” said Healy at a press conference held during ACT Expo 2025 in Anaheim, Calif. “We saw that the adoption of electric vehicles was moving slower than we expected. We saw that the cost of components was skyrocketing, and we saw that regulatory mandates were wavering.

“That same show was the first time that we had shown a glimpse into the Karno generator. This was a technology that we had acquired out of GE Aerospace, and something that we saw is going to be the right solution for charging batteries on board an electric vehicle (EV). So, with that, over the last two years, we made the tough but very proud decision to exit out of the EV powertrain space, and we said why don’t we go all in on the Karno generator.”

The heart of the matter

The Karno Power Module is a fully enclosed, hermetically sealed system housing a four-shaft power module, power electronics and thermal and fuel management systems. At the heart of each unit is the Karno Core, a linear generator that builds on the principles of the 200-year-old Stirling thermodynamic cycle.

“[Stirling engines] were always thought to be the best way to make power. The problem was they were damn near impossible to manufacture,” Healy said. Hyliion was able to “unlock” that manufacturing capability using 3D metal printing (additive manufacturing). “So, we’re basically taking 200-year-old technology and bringing it to the forefront with new manufacturing techniques.”

The Karno Core builds on the principles of the 200-year-old Stirling thermodynamic cycle. (Photo: Hyliion)

Each 200-kW linear generator incorporates linear electric motors with four synchronized shafts that utilize heat to power linear piston movements. These movements generate electricity as the shaft, featuring a magnet array, moves through static copper coils at a high frequency.

This flameless, low-temperature oxidation system, coupled with the unique Karno architecture, requires heat to be supplied only to the core power system, resulting in a fuel-agnostic design. According to Hyliion, the system is compatible with liquid or gaseous fuels that have flame characteristics as slow as ammonia or as fast as hydrogen – with no hardware modifications required.

“We’ve identified over 20 fuels that we expect this ‘box’ will be able to operate on. And unlike some of the other solutions, where you have a platform that then can be adjusted to run on one fuel or another, we’ve designed this where [it] can… switch fuels on the fly, without the generator even having to be turned off,” Healy explained. “We see this as a way to future proof yourself, where you can adopt a solution today that can run on many of the fuels that are expected to be utilized down the road.”

Scalable for multiple applications

The Karno Power Module is designed to deliver clean, dispatchable power on demand with ultra-low to zero emissions without the need for additional emissions treatments. It is also compact and engineered to scale from 200 kW to multiple megawatts.

“As you compare it to internal combustion engines, we’re sitting at about half to maybe a third of the size for the same power output, which is a huge advantage if you think about an EV charging site where space is at a premium,” Healy commented. “These boxes are designed so you can stack them next to each other.

The module’s compact design is an advantage for applications where space is at a premium, including EV charging sites. (Photo: Hyliion)

“We’ve really created the building block. As you need more power, it’s like a battery pack where you put more cells together to get the capacity you need. With this, you put more Karno Cores together to get the power you need.”

Hyliion is also working on a variant that packages 2 MW of power into a housing roughly the size of a 20-ft. shipping container.

While EV charging and data centers are target applications, Healy said the Karno Power Module is capable of providing “true” prime power.

“We see this as a solution not only for EV charging, not only for data centers, but for standard commercial buildings that need power or for waste gas applications or oil and gas sites that are too remote to be able to tap into the grid,” Healy stated.

He also noted that Hyliion has a contract with the U.S. Navy to power future vessels. “They’ve selected it as a power plant of choice for future autonomous Navy vessels as well as other applications,” he said. “Just this past year, we announced around $20 million in funding that has come in from the Navy to help fund the development.

“So, we see this really as a modular solution that can go across many applications.”