Alternative fuels need infrastructure: Why gas bunker vessels matter
As shipping’s fuel landscape becomes more diverse, attention is increasingly turning to the infrastructure needed to supply alternative fuels safely, reliably, and at scale. DNV’s latest white paper explores the growing role of gas bunker vessels, technical matters to be aware of, and the challenges and opportunities associated with supporting LNG today while preparing for the fuels of tomorrow.
The maritime industry is entering a period of growing fuel diversity. While much of the discussion focuses on fuels, engines, and regulations, the transition will also depend on the infrastructure needed to supply alternative fuels safely, reliably, and at scale. DNV’s new white paper, Gas bunker vessels – Facilitating the transition to alternative fuels, details how gas bunker vessels are becoming a critical part of that infrastructure and analyses the key factors shaping their future development, from market growth and vessel design to safety, operational readiness, and the adoption of emerging fuels such as ammonia.
LNG success creates a new supply challenge
LNG has become the most widely adopted gaseous marine fuel and the first to achieve large-scale commercial deployment. According to DNV’s Alternative Fuels Insight platform, around 900 LNG-fuelled vessels are now in operation worldwide, excluding LNG carriers. Around 650 additional vessels are expected to join the fleet before 2030, further increasing demand for LNG as a marine fuel.
As the LNG-fuelled fleet expands, pressure is growing across the entire bunkering ecosystem. LNG consumption by LNG-fuelled vessels increased by more than 500% between 2020 and 2024, with a further 167% growth expected between 2025 and 2030. The white paper argues that bunkering infrastructure is not keeping pace with this rapid expansion, creating a widening gap between fuel demand and available bunkering capacity.
“The LNG bunkering market is well supplied today, but the picture could change significantly as the LNG-fuelled fleet continues to expand,” says Martin Cartwright, Global Business Director, Gas Carriers & FSRUs, DNV Maritime. “Our analysis suggests the global LNG bunker vessel fleet may need to more than double by 2030, with between 165 and 208 vessels potentially required worldwide. Meeting that demand will require coordinated investment across the entire bunkering value chain, not just in the vessels themselves.”
Gas bunker vessels emerge as a key link in the alternative fuel value chain
The report argues that gas bunker vessels should be viewed as more than fuel delivery assets. As shipping adopts a wider range of fuels, they are becoming a critical link between fuel producers, storage facilities, ports, and vessels, helping ensure alternative fuels can be supplied safely, reliably, and at scale.
While gas bunker vessels share many characteristics with conventional gas carriers, their role as fuel suppliers creates a distinct operating profile. Frequent ship-to-ship transfers, interactions with a wide variety of receiving vessels, and the need to operate safely in busy port environments place additional demands on vessel design, operational procedures, safety systems, and crew competence.
“As the maritime industry adopts new fuels and technologies, understanding the bunker vessels that support the transition is becoming just as important as understanding the fuels themselves,” says Robert Østraat Kjelstadli, Principal Engineer, DNV Maritime, and co-author of the white paper. “These vessels are a critical part of the infrastructure that connects fuel supply with vessel operations. Safe and reliable fuel delivery depends on dedicated vessel designs, robust procedures, and the ability to operate efficiently across a wide range of ports and vessel types.”
Converting existing LNG vessels can accelerate capacity growth
Meeting future demand does not necessarily depend on newbuild vessels alone. The white paper highlights the conversion of suitable small-scale LNG carriers into dedicated bunker vessels as a practical way to accelerate capacity growth and support developing bunkering markets.
“Many of these vessels already possess the containment, cargo-handling, monitoring, and safety systems required for liquefied gas operations,” says Yury Ilchenko, Principal Engineer and Gas Carrier Specialist at DNV. “However, successful conversion requires more than adding transfer equipment. Owners must consider factors such as vessel compatibility, ship-to-ship transfer arrangements, vapour and pressure management, manoeuvrability, emergency response, and operational readiness to ensure the vessel can safely perform its new role as a bunker vessel.”
Bunkering safety must scale with LNG demand
As gas bunkering becomes more frequent and geographically widespread, maintaining consistently high standards of safety and operational performance becomes increasingly important.
Unlike conventional marine fuels, gaseous fuels introduce additional considerations around cryogenic handling, vapour management, pressure control, transfer operations, and emergency response. The white paper highlights how safety, resilience, and competence must develop alongside infrastructure if the industry is to scale bunkering operations successfully.
“Gas bunkering is not simply a matter of moving fuel from one vessel to another,” says Ilchenko. “It requires robust procedures, clear responsibilities, resilient systems, and competent people. As operations become more frequent and take place in more locations around the world, maintaining that discipline becomes increasingly important.”
Safe gas bunkering depends on people, procedures, and technology
The report stresses that safe and reliable bunkering depends on translating technical and regulatory requirements into consistent day-to-day practices. Structured safety management systems, compatibility assessments, ship-to-ship transfer procedures, emergency response arrangements, and competence development all have an important role to play.
“Safe gas bunkering is built on a combination of technology, procedures, and people,” says Cartwright. “Operators that establish strong safety management systems, invest in competence development, and adopt a structured approach to risk management will be best positioned to scale operations safely and reliably as demand continues to grow.”
Operational readiness should be considered from the earliest stages of vessel design through to routine bunkering activities. The paper also highlights the value of common operating standards, clear allocation of responsibilities, and the use of industry guidance and checklists to support consistent performance across different ports, vessel types, and operating environments.
Today's LNG bunkering investments could accelerate future fuel adoption
While the report focuses primarily on LNG, it also examines the growing role of other gaseous fuels, particularly ammonia. Recent regulatory developments and updated class requirements are helping make dedicated ammonia bunker vessels a practical possibility, while many of the operational principles developed through LNG bunkering remain directly relevant.
At the same time, the paper argues that today’s investments in LNG bunkering infrastructure have value beyond LNG alone. The vessels, transfer systems, operational experience, and safety frameworks being developed now can help support future fuel pathways, including biomethane, synthetic methane, and ammonia. While the future fuel mix remains uncertain, the need for safe, reliable, and scalable bunkering infrastructure is not.
“The future fuel landscape will undoubtedly be more diverse than it is today,” says Cartwright. “Whatever shape that future takes, safe and efficient fuel supply must keep pace with demand. The infrastructure, expertise, and operational experience being built through LNG bunkering today will help create the foundation for the fuels of tomorrow.”
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