Hundreds of dual-fuel vessels capable of running on clean fuels are currently on order or already entering service globally. Yet, despite fleet readiness, the vast majority continue to burn conventional marine diesel.
The industry is stuck in a waiting game. Vessel operators are ready to transition, but clean fuels cannot yet compete on price with fossil fuels. At the same time, ports and fuel suppliers cannot commit to large-scale infrastructure investments without guaranteed, cost-effective off-take.
Because hydrogen is the fundamental building block for all clean maritime fuels, whether direct hydrogen, e-methanol, or green ammonia, achieving cost parity at the electrolyser level is the single most urgent priority for shipping decarbonisation.
Solving the green hydrogen cost problem is how we will achieve fossil-fuel cost parity without long-term taxpayer drag.
Through homegrown UK technology, the GreenMar consortium is changing the unit economics of green hydrogen to break through this, protect industrial supply chains, and unlock a major global export market.
Removing the Technology Bottlenecks I GreenMar Blueprint
To bring green fuel costs to a point where they compete directly with existing fuels, the GreenMar consortium solves the core technical and environmental barriers that have historically held legacy electrolysers back.
Led by Supercritical Solutions alongside a dedicated group of UK partners, the blueprint tackles every link in the value chain through a unified technological architecture:
- Increasing efficiency and eliminating compression costs (Supercritical): Traditional electrolysers produce low-pressure gas, requiring heavy, power-hungry mechanical compressors to reach maritime storage pressures. Supercritical's ultra-efficient, membraneless technology natively outputs hydrogen at high pressure, stripping out massive CAPEX and energy losses.
- Protecting water resources (Waterwhelm): Electrolysis demands high-purity freshwater, creating severe water scarcity issues. Waterwhelm uses forward osmosis powered by waste heat to transform local wastewater effluent into high-purity electrolyser feedstock, requiring no new freshwater.
- Direct diesel displacement (PlusZero): High-pressure hydrogen is deployed by PlusZero into Hydrogen Internal Combustion Engines (HICE) at Forth Ports, delivering clean shore power and direct vessel refuelling to replace diesel immediately, both onshore and offshore.
- Pioneering adopter (Forth Ports): An organisation collaborating to explore emerging technology, leading the way to develop capabilities to meet their net zero goals and sustain long-term business value.
- Planet-First Engineering: Legacy systems rely heavily on scarce precious metals like iridium and persistent "forever chemicals" (PFAS). The Supercritical architecture replaces fragile membranes and critical raw materials with a robust, all-metal stack design.
- Scaling UK Manufacturing (Manufacturing Technology Centre - MTC): The MTC provides advanced manufacturing expertise to scale stack production efficiently within the UK.
- Strategic Advisory & Investment Backing: The initiative is supported by strategic technical advisory and investment from supportive industrial backers.
By targeting a levelised cost of hydrogen (LCOH) of £4/kg, this collective effort establishes a viable alternative to fossil fuels in maritime that works within market realities.
An Engine for UK Jobs and Exports
Solving maritime decarbonisation is both an environmental necessity and an opportunity to insulate the UK economy from the fossil fuel price rollercoaster.
By anchoring technology, intellectual property, and supply chains in the UK, this approach creates high-skilled engineering jobs, revitalises port communities, and protects industrial clusters from wholesale energy spikes. As UK nameplate manufacturing scales toward 1GW, this homegrown solution offers an exportable platform to decarbonise global trade routes and drive economic growth.
