Marine
Decarbonizing the Oceans
International shipping moves nearly 90% of world trade and is responsible for roughly three percent of global greenhouse gas emissions. Regulatory pressure on the sector is intensifying. The IMO’s 2023 strategy targets a 20% reduction in shipping emissions by 2030 and a 70% reduction by 2040 against 2008 levels, with the goal of net zero by or around 2050. The EU’s FuelEU Maritime regulation, already in force since January 2025, adds a parallel layer of compliance requirements for ships calling at European ports.¹
This regulatory shift is reshaping how vessels are financed. Under the Poseidon Principles, a framework through which signatory banks assess the climate alignment of their ship finance portfolios against IMO targets, carbon intensity performance is now a factor in lending decisions, not just an environmental metric. For shipowners, this means access to capital is increasingly tied to demonstrating a credible pathway to a low-emission drivetrain, not simply meeting minimum compliance.²
Demand for marine fuel cells reflects this shift. Market estimates vary by scope and methodology: more conservative projections put the market at roughly $450 million by 2030 (from $215 million in 2023),³ while broader estimates value it at approximately $2.5 billion in 2023, growing toward $5.7 billion by 2032.⁴ Even at the lower end, the estimates point to clear and sustained growth.
The legacy technology for marine propulsion and auxiliary power is the internal combustion engine (ICE) running on marine diesel. An emerging alternative replaces marine diesel with electro-fuels in the same combustion engines, but this approach inherits the fuel efficiency limitations of combustion-based propulsion, limiting how far it can close the gap to genuinely low-emission operation.
Beyond Combustion
Systems based on Catator’s CataRex® technology reform electro-fuels and convert them into electricity through a thermally integrated solid oxide fuel cell (SOFC), bypassing combustion entirely. Where conventional electro-fuel adoption simply substitutes a cleaner fuel into the same combustion engine, Catator’s approach replaces the combustion process itself with catalytic reforming and electrochemical conversion.
This matters directly for the financing and compliance pressures shipowners face. A vessel powered by a reformed electro-fuel and SOFC system reduces fuel consumption per unit of power delivered, lowering both operating cost and the carbon intensity metrics that determine access to capital under frameworks such as the Poseidon Principles and FuelEU Maritime.
Double Efficiency with Fuel Flexibility
Replacing combustion-based propulsion with a system based on Catator’s CataRex® technology delivers two advantages that compound over the lifetime of a vessel.
Fuel efficiency is roughly double that of a conventional marine ICE running on the same fuel. Because the SOFC converts fuel to electricity electrochemically rather than through combustion, a far greater share of the fuel’s energy content is captured as usable power rather than lost as heat. For shipowners, this directly reduces fuel operating costs and improves the carbon intensity metrics used in green financing assessments.
The system is also fuel-flexible, supporting a range of electro-fuels rather than locking operators into a single feedstock. This is a meaningful advantage in a market where alternative fuel infrastructure, pricing and availability are still maturing and vary significantly by region and bunkering port. A multi-fuel solution gives shipowners the flexibility to adapt as the fuel landscape develops, rather than committing to infrastructure built around one fuel choice.
Key Applications
Systems based on Catator’s CataRex® technology are positioned to displace marine ICE incrementally rather than all at once.
- Gradual displacement of marine ICE, starting with auxiliary power units (APUs) and extending over time to the main propulsion drivetrain.
Sources:
¹ Maritime shipping regulation & compliance guide. DNV. https://www.dnv.com/maritime/decarbonize-shipping/regulations/
² Poseidon Principles for Financial Institutions. https://www.poseidonprinciples.org/finance/
³ Fuel Cells for Marine Vessels Market Size, Share | Industry Trend & Forecast 2030. IndustryARC. https://www.industryarc.com/PressRelease/4355/Fuel-Cells-for-Marine-Vessels-Market
⁴ Fuel Cells Marine Vessels Market Research Report. Market Research Future. https://www.marketresearchfuture.com/reports/fuel-cells-marine-vessels-market-6111