Battery Energy Storage Systems form a key part of renewable energy strategies. It is expected that there will be a rise in the number of battery energy storage systems being installed in dwellings given their effectiveness of storing energy from renewable energy technologies such as solar photovoltaic systems.
PAS 63100:2024 Electrical installations – Protection against fire of battery energy storage systems for use in dwellings was published in March 2024. PAS 63100 aims to help installers reduce the risk of batteries in dwellings becoming a source of ignition and to limit the impact of a battery fire should one occur. The basic premise is that the best place for storage batteries is outside dwellings and away from habitable rooms.
Type 6 of schedule 1 of the Building (Scotland) Regulations 2004 covers “Detached fixed plant or machinery or a detached building housing only fixed plant or machinery, the only normal visits to which are intermittent visits to inspect or maintain the fixed plant or machinery”. It is considered that battery energy storage systems would fall into this category and would not require a building warrant provided the building / plant is 1m or more away from the boundary. The same principle applies for non-domestic buildings.
Whilst battery fires, at the time of writing, are low frequency, they have a high impact due to their behaviour in fire. Since some batteries can exhibit focussed jet-like flaming, a higher degree of fire compartmentation should be considered. PAS 63100 recognises that fire compartmentation requirements might need to be assessed in future editions of this standard, as there are currently gaps in the knowledge of how fire compartmentation resists lithium battery fires.
For non-domestic applications, BS EN IEC 62619:2017 which specifies requirements and tests for the safe operation of secondary lithium cells and batteries used in industrial applications including stationary applications. IEC 63056:2020 specifies requirements and tests for the product safety of secondary lithium cells and batteries used in electrical energy storage systems with a maximum DC voltage of 1,500 V (nominal). IEC 63056:2020 provides additional or specific requirements for electrical energy storage systems beyond the basic safety requirements covered by IEC 62619. It applies to cells and batteries for uninterruptible power supplies (UPS) but does not cover portable systems with a capacity of 500 Wh or below, which are addressed by IEC 61960-3 1.
It is proposed that further research for both domestic and non-domestic buildings is required to inform future policy decisions, for example related to compartmentation, early warning of fire, definition of place of special fire risk etc.
