MARAD releases LNG Bunkering study

Study examines the pros and cons of four bunkering options

The Maritime Administration (MARAD) released a comprehensive study examining the options for liquefied natural gas (LNG) bunkering and the necessary infrastructure, safety, regulatory, and training factors of each in supplying LNG to ships as a propulsion fuel in the maritime sector. Bunkering is the transfer of LNG from a supply station to a receiving vessel for the sole purpose of use as propulsion fuel.

The study examines the pros and cons of four bunkering options (truck-to-ship transfer, shore facility-to-ship transfer, ship-to-ship transfer, and transfer of portable tanks) based on factors such as the number and type of vessels to be served, local availability of LNG, port size, congestion and level of activity.

1. Truck-to-Ship (TTS): is the most common method used to support the LNG-fueled ship network, to date.It is the transfer of LNG from a truck’s storage tank to a vessel moored to the dock or jetty. Typically,this is undertaken by connecting a flexible hose designed for cryogenic LNG service. A typical LNG tanktruck can carry 13,000 gallons of LNG and transfer a complete load in approximately one hour.

2. Shore/Pipeline-to-Ship (PTS): LNG is transferred from a fixed storage tank on land through a cryogenicpipeline with a flexible end piece or hose to a vessel moored to a nearby dock or jetty. These facilitieshave scalable onsite storage such that designs could be capable of performing bunkering of largervolumes than TTS or with portable tanks.

3. Ship-to-Ship (STS): It is the transfer of LNG from one vessel or barge, with LNG as cargo, to anothervessel for use as fuel. STS offers a wide range of flexibility in location bunkering, and flexibility onquantity and transfer rate. There are two types of STS bunkering operations, one is performed at theport, and the other is carried out at sea. This has only been carried out at the Port of Stockholm for thenew LNG-fueled ferry, Viking Grace.

4. Portable tanks: They can be used as portable fuel storage. They can be driven or lifted on and off avessel for refueling. The quantity transferred is flexible and dependent on the number of portable tankstransferred. A 40-foot (ISO-scale) intermodal portable tank can hold approximately 13,000 gallons ofLNG

The study also makes recommendations to regulators, port operators, vessel operators and LNG infrastructure owners on ways to address the challenges associated with widespread use of LNG as a marine propulsion fuel and provides information to help them decide which method may be most appropriate for their needs.

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Ship-to-Ship Bunkering of LNG

Advantages

Disandvantages

-Refueling at sea is possible; eliminates the need tocome into a port

– In port mobility allows for transfers to take place inprotected areas or away from sensitive areas andcritical infrastructure

– Large transfer volumes are possible at highbunkering flow rates

– Transfer rates approach shore-to-ship bunkeringcapabilities; exceed truck-to-ship option

– Remote locations reduce/eliminate potentialexposure to vulnerable targets

– Exposes both vessels to full sea state

– Currents

– Wind

– Waves

– Higher investment and operational cost than shoreand truck-to-ship options

– Requires some shoreside infrastructure for loadingLNG as cargo

LNG Bunkering Threats

Although LNG is recognized as a cleaner energy source with lower NOx, SOx and particulate matter (PM)emissions, operators face challenges transporting and using LNG as fuel. Unavailability of LNG may increasethe cost of LNG fuel, reducing one of the main drivers for its adoption. It is more likely that LNG will be thecheaper alternative in the short-term, for ships operating predominantly within the U.S

Deploying a robust LNG infrastructure will help ensure safe and reliable transport and use. The threats thatcould prevent safe and reliable bunkering operations may be categorized under infrastructure, publicperception, location restrictions, policy and regulations, and natural hazards conditions

Key Findings

There is no single bunkering option that can meet the requirements of all port stakeholders.
Initial developments are cooperative, minimizing the risk to first movers.
No LNG bunkering option will dominate since first movers dictate initial development based onspecific project needs.
TTS bunkering will be utilized by vessels with smaller fuel tank capacities (e.g., tugs) and for remoterefueling where infrastructure is not currently established (e.g., ferries).
PTS bunkering will be primarily developed for larger fueling needs through partnerships with vesseloperators or designed to vessel needs (e.g., Harvey Gulf).
STS bunkering may grow significantly, but it may only be considered where shore-based options areless attractive or infeasible.
Management of risks to the public, workers, critical infrastructure, and business interruption will beessential to prevent catastrophic events that may affect the natural gas/LNG industry

Further information may be found by reading LNG Bunkering Study