The report Maritime Electrification: Maritime Battery Systems and Onshore Power Supply, published by Bureau Veritas Marine & Offshore in May 2025, takes a critical look at the regulatory framework for shipboard energy storage systems (ESS) and onshore power supply (OPS) solutions. At a time when lithium-ion batteries are becoming central to the electrification of the world fleet, the document points to standards that are still fragmented, often optional, and insufficiently binding. This gap could compromise crew safety and slow down the adoption of these technologies.
Marine battery safety: fragmented regulations
The boom in energy storage systems (ESS) on board ships is accompanied by a worrying observation: the regulatory framework remains partial and non-binding. While standards for shore power systems (OPS) are defined by the IEC (standards 80005-1 and 80005-3), marine batteries are evolving in a relative standards vacuum. The main risk identified is that of thermal runaway of lithium-ion batteries, which can cause fires that are very difficult, if nigh on impossible to control.
In response to this void, Bureau Veritas offers in-house rules such as NR467, which specify design, installation and safety requirements for marine batteries. This standard defines minimum protection indices (IP), compartment layout, monitoring requirements (BMS) and thermal management (BTMS). These rules are based on the specific properties of different battery chemistries NMC, LFP, LTO, each with its own advantages and limitations in terms of energy density, thermal stability or cost.
Unlike ESS, OPS systems are largely covered by international standards. They enable ships to be powered at berth without the need for diesel generators, thus reducing local emissions. However, the integration of these systems requires greater standardization of connectors, voltages and frequencies. The “any ship, any port” approach presupposes harmonization that is still far from generalized. In Europe, the AFIR regulation provides for their installation in TENT-T ports by 2029.
The report warns against the absence of standardized crew training procedures, emergency protocols or predictive maintenance obligations. The marine environment imposes specific constraints: humidity, vibrations, temperature variations, salty atmospheres… Each factor accentuates the risks associated with batteries, particularly as they age. Bureau Veritas therefore recommends sizing to take foreseeable degradation into account, and a modular design with compartmentalized systems to limit the spread of incidents.
In the absence of international regulatory guarantees, many shipowners remain wary of adopting battery systems, despite growing pressure to decarbonize (EU ETS, FuelEU Maritime, IMO 2050). The cost of installation, combined with a lack of regulatory visibility, still limits the perceived profitability of these solutions, particularly for ocean-going vessels.
If marine electrification is to reach its full potential, international coordination of safety standards is essential. The industry could draw inspiration from the OPS initiative to structure a global framework for SSEs. At a time when the number of hybrid or 100% electric ships exceeds 1,000, standardization is a sine qua non for accelerating the industry.