FleetZero aims to Help Rewirte the Rules of Marine Power

There’s a familiar narrative in maritime: an industry steeped in tradition, slow to change, and cautious when it comes to new technology. But every so often, a company emerges that doesn’t just challenge the status quo, it questions the underlying assumptions that built it.

That’s precisely where FleetZero finds itself today.

Founded in 2021 by Mike Carter and Steven Henderson — lifelong friends and graduates of the United States Merchant Marine Academy — FleetZero have moved from concept to commercialization. With roughly 40 employees, $60 million raised, and plans to produce 300 MWh of batteries annually at its new Houston headquarters, the company is scaling fast.

But the real story isn’t only the numbers. It’s the thesis.

Challenging the “Future Fuel” Orthodoxy

FleetZero’s origins trace back to the early pandemic days, when Carter and Henderson began questioning a dominant industry narrative: that the future of maritime propulsion would be defined by alternative fuels such as ammonia or methanol.

“We just didn’t subscribe to it,” Carter explains.

Instead of following the crowd, the duo did something deceptively simple, they ran the numbers. They examined fuel pathways, vessel operations, and real-world data, including AIS behavior and load profiles. What they found upended conventional thinking.

Battery propulsion, they concluded, wasn’t just viable, it could be cost-advantageous versus diesel across multiple vessel classes, including tankers, bulkers, and container ships.

The catch? Existing battery systems weren’t built for the job.

Leviathan: Built by Mariners, for Mariners

FleetZero’s answer is its flagship product, the Leviathan modular battery energy system, a platform designed specifically for marine environments. Carter is blunt about the starting point: “The systems we looked at weren’t cheap enough, and they weren’t safe enough.”

Leviathan aims to solve both.

The system delivers roughly twice the energy density at half the cost of competing marine battery solutions, Carter says, a combination that he calls a “huge unlock” for vessel electrification.

At its core is lithium iron phosphate (LFP) chemistry, an inherently safer alternative to nickel-based batteries, paired with proprietary packaging and materials that maximize energy density without sacrificing safety. The result is a system designed not just to meet regulatory thresholds, but to satisfy the instincts of mariners themselves.

“We would feel more than comfortable sleeping on top of it while sailing,” Carter says.

That’s not marketing language, rather design philosophy.

System-Level Thinking: Enter “Kraken”

If Leviathan is the engine, FleetZero’s upcoming Kraken system is the connective tissue.

Kraken is a compact integration platform that links battery strings together while dramatically reducing the footprint typically required for switchboards and electrical infrastructure. The payoff is twofold: higher overall system energy density and lower integration costs.

For shipowners and integrators, that matters.

Space onboard a vessel is always at a premium. By shrinking the electrical architecture, FleetZero isn’t just improving performance; it’s making electrification projects more feasible from both a design and economic standpoint.

Image Courtesy FleetZero

The system delivers roughly twice the energy density at half the cost of competing marine battery solutions, Carter says, a combination that he calls a “huge unlock” for vessel electrification.

Houston: A Strategic Base for Scale

FleetZero’s decision to establish its headquarters in Houston is no accident. “It’s one of the few cities in America where things really get done,” Carter says. Between the Port of Houston, the energy sector, NASA’s engineering ecosystem, and a deep labor pool of electricians and power systems experts, the city offers a rare convergence of maritime, industrial, and electrical expertise.

From this base, FleetZero is preparing to scale manufacturing while continuing R&D across its other locations in Alabama and Montreal.

Beyond Batteries: Rethinking Shipbuilding

Perhaps most intriguing is FleetZero’s longer-term ambition, not just to power ships, but to rethink how they’re built.

The company is exploring modular hull construction concepts that echo the efficiency of WWII-era Liberty ships, but updated with modern manufacturing techniques, including prefabrication and distributed production.

Think hull sections manufactured inland — possibly even “printed” — and shipped to coastal yards for assembly. It’s early-stage, but it signals a broader vision: electrification as part of a larger industrial reset.

Looking at the company’s evolution holistically, FleetZero’s story is not just about batteries. It’s about challenging assumptions in an industry that has long accepted them as fixed truths.

The company’s core industry insight – that ships don’t operate at maximum power continuously, and that battery economics have shifted dramatically — may seem obvious in hindsight. But it’s precisely these overlooked realities that create opportunity.

As Carter and his team push toward commercialization milestones over the next 12 to 24 months, the question isn’t whether batteries will play a role in maritime. That debate is largely settled. The real question is how far and how fast it can go.

If Carter is right, the answer may be: much farther than anyone expected.