Safety distance standards for energy storage containers

Electrical energy storage (EES) systems - Part 5-3. Safety requirements for electrochemical based EES systems considering initially non-anticipated modifications, partial replacement, changing application, relocation and loading reused battery.

Far-reaching standard for energy storage safety, setting out a safety analysis approach to assess H&S risks and enable determination of separation distances, ventilation requirements and fire protection strategies. References other UL standards such as UL 1973, as well as ASME codes for piping (B31) and pressure vessels (B & PV).

Introduction As the industry for battery energy storage systems (BESS) has grown, a broad range of H&S related standards have been developed. There are national and international standards, those adopted by the British Standards Institution (BSI) or published by International Electrotechnical Commission (IEC), CENELEC, ISO, etc.

Therefore, these separation distances vary between 0.9 m and 3 m. The recommended maximum stored energy is 600 kWh for locations near exposures, garages, rooftops, and for mobile BESS. The limit for the exterior wall is 20 kWh. It is recommended that the groups of 50 kWh should be spaced with distance of 0.9 m between each other.

In UK1 it is mentioned that the guidance on appropriate separation distances between BESS containers is provided in UK2. In UK2, a minimum spacing of 6 m between BESS units is suggested, though reduced distances are allowed if supported by documentation.

FrazerNash are the primary authors of this report, with DESNZ and the industry led storage health and safety governance group (SHS governance group) providing key insights into the necessary content. This guidance document is primarily tailored to 'grid scale' battery storage systems and focusses on topics related to health and safety.