Lloyd’s Register issues first Guidance Notes for onboard hydrogen generation as industry seeks regulatory clarity

The Guidance Notes provide clear technical direction for the design, installation and integration of onboard hydrogen generators.

Lloyd’s Register (LR) has published the maritime industry’s first dedicated Guidance Notes for onboard hydrogen generation, providing long-awaited clarity on the safe design and integration of hydrogen generator technologies on ships.

The new Guidance Notes respond directly to growing interest from shipowners, yards and technology developers in producing hydrogen onboard using alternative fuels such as LNG, methanol and ammonia.

While hydrogen is widely seen as a key fuel for decarbonisation, limited supply and availability of complex bunkering infrastructure significantly slow adoption in shipping. In addition, onboard storage may also pose challenges due to space demands and system complexity, adding further barriers to implementation.

Onboard hydrogen generation offers a practical bridge to the future of zero-emission shipping. By producing hydrogen directly on board, shipowners can avoid the need for space-demanding and complex compressed or liquefied hydrogen storage systems and eliminate dependence on the future development of widespread hydrogen supply chains and bunkering infrastructure. At the same time, they position themselves for compliance with tightening emission requirements and future decarbonisation regulations.

However, onboard hydrogen generation also presents safety and regulatory challenges due to the presence of two gases or low-flashpoint fuels and the absence of mature international regulations. Drawing on established LR Rules for fuel cells and low-flashpoint fuels, the Guidance Notes provide a clear, risk-based framework that reduces uncertainty, supports plan approval and accelerates project delivery for newbuilds and retrofits.

The Guidance Notes set out practical requirements for the design, safety and onboard installation of hydrogen generators, recognising the challenges of adapting land-based technologies for the marine environment. By aligning safety principles with existing class requirements, they offer a consistent and credible basis for engagement with flag Administrations and other stakeholders.

For shipowners, yards and technology providers, the Guidance Notes are expected to reduce technical and regulatory uncertainty for projects currently under development, helping to shorten approval timelines and de-risk investment decisions in hydrogen-based solutions.

Thomas Bayer, Lead Specialist Fuel Cell Technology, Technical Directorate, Lloyd’s Register, said: “Clear guidance is essential for emerging technologies. The industry cannot afford to stand still while formal regulations are developed; our Guidance Notes provide the clarity needed to move projects from concept to delivery.

“By publishing dedicated guidance ahead of formal international standards, LR reinforces its position as a trusted advisor on emerging technologies and a leader in supporting the maritime industry’s transition to low- and zero-carbon energy.”

The Guidance Notes are available now via the LR website at: LR-GN-061 Guidance Notes for Onboard Hydrogen Generation | LR

LR recently published the latest report in its award-winning Fuel for thought series, providing a comprehensive assessment of hydrogen’s potential role in maritime decarbonisation.

Fuel for thought: Hydrogen examines hydrogen from production and supply through to onboard use, highlighting the fuel’s advantages alongside the safety, infrastructure and cost challenges that currently restrict its adoption. Read it here: Fuel for thought: Hydrogen | LR

About Lloyd’s Register             

Trusted maritime and energy sector advisors, partnering with clients to drive performance across the ocean economy.  

Lloyd’s Register (LR) is a global professional services group specialising in marine and offshore engineering, technology and digital solutions. We were created more than 260 years ago as the world’s first marine classification society to improve and set standards for the safety of ships.  

Today we are a leading provider of classification and compliance services to the marine and offshore industries, helping our clients design, construct and operate their assets to accepted levels of safety and environmental compliance.  

We also provide advisory services and digital solutions, supporting fleet and voyage performance and optimisation.   

Our digital solutions are relied upon by more than 30,000 vessels, following the acquisition of OneOcean in 2022 and Ocean Technologies Group in 2024.  

In the race to zero emissions, our research, advisory and technical expertise and industry-firsts are supporting a safe, sustainable maritime energy transition.  

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For more information, go to www.lr.org