The latest ventilation standards for energy storage containers

Ventilation is advised as well for outdoor BESS in containers. When it comes to battery storage, ventilation is recommended if the storage capacity is over 1200 kWh at 100% SOC or over 2400 kWh at 50% SOC. When storing batteries in containers, outdoors ventilation is required for capacities under 1200 kWh at 100% SOC or under 2400 kWh at 30% SOC.

However, Danish guideline provides clear BESS capacity limits for ventilation. However, more guides on explosion prevention are given in Swedish and USA guidelines, including ventilation rates, safe ventilation for firefighting etc.

Ventilation is suggested as the main explosion mitigation measure. However, most reviewed guidelines do not provide specific recommendations on the situation when ventilation should be installed. Most of the guidelines recommend the use of a water suppression system. Other types are also mentioned, though their efficiency should be tested.

DK2 is the only document that provides detailed capacity thresholds for ventilation installation. For indoor BESS installations over 600 kWh, DK2 recommends installing ventilation. Ventilation is advised as well for outdoor BESS in containers.

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. According to USA2, the space separation between BESS enclosures and adjacent buildings or critical site utilities or equipment are stated in the FM Global Data Sheet 1-20 .

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.