Image of fire sprinkler in energy storage cabin

Is a sprinkler system a fire hazard?

While it is recognized that the fire hazard posed by an ESS system is in part a function of the electrical capacity and battery chemistry, additional sprinklered fire testing is recommended to confidently reduce the sprinkler demand area, water duration, or separation distances.

How far from combustibles can a sprinkler system be separated?

Similar calculations based on the peak 60-s average heat flux measurements during the intermediate-scale tests, detailed in Section 5, result in separation distances for the LFP system of 0.9 m (3 ft) from non-combustible objects and less than 1.2 m (4 ft) from combustibles when sprinkler protection is not present.

Is sprinkler protection sufficient for ESS in commercial occupancies?

These recent efforts provide confidence that sprinkler protection can be sufficient for ESS in commercial occupancies. However, there are limited real-scale data available to support a fire hazard assessment of Li-ion based ESS and there are no experimental data to support sprinkler protection guidance. (e.g., battery, module).

Should ESS racks be separated as combustibles if sprinkler protection is not provided?

For ESS comprised of multiple racks, each individual LFP or NMC rack should be separated as combustibles per Table 7-2 when sprinkler protection is not provided. Refer to Section 7.1.2 for additional guidance when sprinkler protection is provided.

Does sprinkler protection prevent a single module from spreading?

For both the LFP and NMC tests, sprinkler protection did not prevent ignition of a single module from spreading to involve the entire rack. As shown in Section 6.2, sprinkler protection was sufficient to control the fire to the rack of origin during the LFP test, whereas the fire spread to the adjacent target rack during the NMC test.

How big a fire can a sprinkler be under a ceiling?

7.6 m (15 ft to 25 ft). For the LFP test, the limited fire size was sufficient to operate a QR or SR sprinkler under a 4.6 m (15 ft) ceiling when the fire size was in the range of 110 to 170 kW (104 to 161 BTU/s). However, sprinklers were not predicted to operate when the ceiling was raised to 6.1 m (20 ft) or higher.