Gard: Safe carriage of Battery Energy Storage Systems on ships

Gard published that in the past few months, has received several queries on the safe carriage of battery energy storage systems (BESS) on ships and highlights some of the key risks, regulatory requirements, and recommendations for shipping such cargo.

As explained, according to the International Energy Agency, energy storage systems (ESS) will play a key role in the transition to clean energy. Sometimes referred to as “energy storage cabinets” or “megapacks”, ESS consist of groups of devices that are assembled together as one unit and that can store large amounts of energy.

Battery energy storage systems (BESS) are the most common type of ESS where batteries are pre-assembled into several modules. BESS come in various sizes depending on their application and their usage is expected to rise considerably in coming years. Although different kinds of batteries can be used in BESS, lithium-ion batteries seem to be the most popular. Our focus in this article is therefore on energy storage systems equipped with lithium-ion batteries.

Declaration of BESS

Siddharth Mahajan, Senior Loss Prevention Executive, Singapore highlights that BESS with lithium-ion batteries is classed as a dangerous cargo, subject to the provisions of the IMDG Code. In the IMDG Code, there are multiple descriptions and shipping names for lithium cells and batteries, depending on their chemistry and whether they are stand-alone, within equipment, contained within vehicles or cargo transport units. This has caused some confusion among shippers about how to correctly declare this cargo. We have come across instances where a BESS is declared as either:

UN 3480 (Lithium-ion batteries), or
UN 3481 (Lithium-ion batteries contained in equipment or lithium-ion batteries packed with equipment), or
UN 3536 (Lithium batteries installed in cargo transport unit).

Carriers should also be aware of the applicability of the different special provisions (SP) of the IMDG Code. SP 389 (which mentions the securing of batteries to the interior structure of the cargo transport unit) is applicable only to UN 3536. Similarly, a lot of other SPs which are applicable to UN 3480 and UN 3481 do not apply to UN 3536. There are some changes proposed to UN 3536. For more details on this, see below in the section ‘stowage and securing’.

Fire and explosion risks

Potential fire and explosion hazards of Lithium-ion batteries have become a “hot topic” in the shipping industry, as detailed in this recent Gard article. As a precautionary measure, owners should therefore enquire about the state of charge (SoC) of the BESS before accepting shipment. The SoC has a direct influence on the likelihood of thermal runaway fire, and also on the growth and peak heat release rate. This has been highlighted by several industry bodies and regulators, such as EMSA’s Guidance on the carriage of AFVs, and AMSA’s guidance on risks associated with the carriage of battery electric vehicles. A minimal SoC is therefore recommended during transportation.

Although most BESS have an inbuilt battery management and cooling system, thermal runaway events can occur. Should such an event happen, most units are designed to vent from the top. If the BESS is stowed in a hold, the hold space may then be filled with a significant amount of toxic vapour, a build-up of which could lead to a vapour cloud explosion. Venting the space could be difficult, and given the volatility and toxicity of the gases, due regard needs to be given to avoid igniting the vapour cloud. Containment is recommended as far as possible and calling in an expert to advise. Certain units may be equipped with safety systems that could allow the crew or someone ashore to monitor the units and be alerted before a dangerous situation develops. Crew should be made aware of the toxicity of the vapours released and care should be taken to ensure that the gases do not enter areas where crew members are present.

Stowage and securing

For bulk carriers and general cargo vessels carrying BESS, consideration will have to be given to the following areas:

Securing arrangement and cargo spaces: If the vessel does not have sufficient securing arrangements, they will need to be fabricated in the presence of expert supervision and all such modifications would require the Administration’s approval.
Structural strength of the tank top and hatches: The structural strength of the tank top, as well as the hatch covers needs to be verified.
Cargo securing manual (CSM): It should be verified if the CSM incorporates carriage of such cargoes. Amendments may also be required in some cases covering the lashing arrangements and stowage of such units, which must be approved by the Administration.
Approvals: Approvals from the vessel’s Classification Society and Flag State may also be required. Owners are advised to contact their Classification Societies and Flag States early to better understand the various requirements and approval process.

Recommendations

Ensure cargo is loaded in accordance with IMO statutory requirements, the vessel’s CSM, CSS Code, and IMDG Code.
Vessel’s Classification Society and/or the Flag State should be contacted for necessary approvals.
Owners are advised to request the charterers and shippers to provide information on special handling instructions, state of charge, type of batteries, in-built safeties, and clear guidance on emergency response.
It is recommended to adopt a risk-based approach when deciding on the stowage location of BESS, wherein consideration can also be given to the draft amendments to the IMDG Code (42-24).
The vessel may need to be equipped with additional fire safety equipment to detect and respond to fire and explosion. Owners and Managers are also advised to provide the crew with cargo-specific guidance and training on emergency response.