Rising LNG demand: Overcoming bunkering challenges

LNG markets are experiencing significant growth. This surge is driven by rising global demand for natural gas, particularly from China, and disruptions caused by major geopolitical events like the conflict in Ukraine. As a result, LNG demand has reached unprecedented levels.

LNG marine fuel use surges amid decarbonization efforts

The use of LNG as a marine fuel is also skyrocketing, driven by market and regulatory pressure to decarbonize the maritime industry. According to DNV’s Alternative Fuels Insights (AFI) platform, 642 LNG-powered vessels are currently in operation, excluding LNG carriers. Of these, 169 were delivered in 2024, setting a record. Additionally, 264 new orders for LNG-fuelled vessels were placed in 2024, also a record and more than double the number of orders placed in 2023.

The growth curve is set to get even steeper: according to the AFI order book, the number of LNG-powered vessels in operation is set to double by the end of the decade.

LNG bunkering infrastructure lagging behind demand

With the LNG fleet expanding rapidly, the need for supporting LNG bunkering infrastructure is intensifying. The amount of LNG consumed by LNG-fuelled ships has already seen a steep increase, with over 500% growth registered between 2020 and 2024.

A similar growth rate is expected over the next five years. However, LNG bunkering vessels are not keeping pace, resulting in a significant gap between LNG bunkering supply and demand, with the issue being more pronounced in some regions than others.

A closer look at the LNG bunkering fleet

In general, there are three categories of small and medium-sized LNG bunkering vessels: LNG feeder vessels, LNG bunker vessels and LNG bunker barges. These range between 1,000 and 20,000 m³ in capacity and can be used either in or out of port.

Some 64 LNG bunkering vessels are in operation today, with a further 16 on order.  Around 42% of these vessels are larger than 10,000 m³, with another 37% in the 5,000 to 10,000 m³ range.

These vessels are quite evenly spread across the globe, with 42% located in Europe, 28% in Asia and 18% spread across North and South America.

Of the LNG bunkering vessels on order, three are expected to come online in 2025, with a further five scheduled for completion in 2026 and the remaining expected to be delivered in 2027 and 2028.

In 2024, there were 191 ports with active LNG bunkering facilities, such as LNG storage tanks and dedicated berths for LNG bunkering vessels, as well as ready access to LNG supply. A further 81 ports have facilities under construction.

Closing the gap

Looking at the order book, this gap between LNG bunkering demand and supply is expected to get even wider over the next five years. How can this be closed?

More yard space is crucial. In recent years there has been a shift in the kinds of yards that have an appetite to build these kinds of vessels. In particular, several yards which were previously engaged in constructing small gas carriers have progressed towards the construction of medium and large gas carriers, so there are now different yards at play for the smaller-sized vessels.

Key safety considerations for LNG bunkering

LNG bunkering is a complex business, and when it comes to safe operation some key considerations need to be taken into account.

One critical aspect of LNG management is handling the cargo heel, which involves maintaining a small amount of LNG in the tank to keep its temperature stable. This practice prevents the tank from warming up and generating excessive boil-off gas, which can lead to increased pressure.

Managing pressure during loading is crucial. To avoid overpressure situations, it is essential to monitor and control tank pressure. Pressure relief systems help manage any excess pressure effectively.

Additionally, effective vapour management is crucial for handling the boil-off gas produced during bunkering. This can be done by re-liquefying the gas, using it as fuel, or safely venting it.

Ensuring safe and steady LNG loading

The LNG loading process must be carefully controlled to ensure a steady and safe transfer. Monitoring flow rates and temperatures is crucial to prevent rapid changes that could cause thermal stress. The vapour return flow system is essential during loading, as it returns displaced vapours from the receiving tank back to the supply tank, maintaining pressure balance and reducing the risk of overpressure.  

Additionally, overpressure protection systems, such as pressure relief valves, are vital to prevent tank rupture or damage. These systems automatically release pressure if it exceeds safe limits, ensuring the integrity of the tanks and the safety of the entire operation.  

The importance of redundancy measures in LNG bunkering

Certain safety practices should be observed at all times during LNG bunkering. Redundancy measures are crucial, ensuring backup systems can handle any failures or malfunctions. If a component like a propeller, pressure relief valve or cargo pump fails, another can take over to maintain safety and prevent accidents. These measures also ensure smooth commercial operations and an uninterrupted LNG supply chain.

At DNV, we support the LNG bunkering industry with notations like AP (alternative propulsion), RP (redundant propulsion) and Gas Bunker, ensuring strong redundancy on vessels. We have been involved in developing bunkering procedures and will continue to help the industry evolve.

Training is crucial as LNG bunkering becomes more common. More trained personnel, including LNG vessel crews and bunkering specialists, will be needed to ensure smooth and safe operations.

Shore power – a promising solution for LNG bunker vessels

While LNG use reduces emissions by around 20% compared to conventionally fuelled vessels, further reductions are necessary. Options include energy efficiency technologies like fuel cells, but shore power appears most promising.

DNV’s Maritime Forecast to 2050 report shows that well-to-wake emissions from on-board generators are higher than almost all cases of shore power, even when produced from fossil fuels. Shore power also benefits local environments by reducing direct emissions. The report estimates that port power accounts for about 7% of total maritime industry power use, much of which can be abated with shore power.

Push for shore power expansion for bunkering vessels

While this is promising, the nature of bunkering vessels means that this figure can be much higher. Bunkering vessels tend to operate close to or within port limits. Like ferries, their routes are short and predictable, making them ideal candidates for shore power, electrification and battery use.

For this to become more prevalent, more buy-in is needed from LNG bunker vessel operators, fuel owners and especially port owners and operators. Significant investment is required to expand and modernize infrastructure at terminals. These players will also need support from local authorities to modernize and expand grid capacity to handle increased demand.

Ports like Abu Dhabi, Rotterdam and Los Angeles are making strides in shore power infrastructure.

Broad prospects for LNG bunkering vessels

What does the future hold for LNG bunkering vessels? It is now clear that the lifespan of LNG as a marine fuel is likely to be significantly longer than many stakeholders believed a few years ago. If the need for these vessels diminishes in the future, they can be repurposed as interregional LNG carriers for small-scale LNG trade.

More importantly, these vessels could be used for bunkering bio and synthetic LNG, provided we develop more efficient value chains for these green fuels. These fuels are compatible with current LNG infrastructure and engines, offering a path to greener ambitions.

LNG bunkering vessels are in high demand, and those investing now can be confident that these vessels will be utilized for many years, playing a key role in the maritime energy transition.

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