Researchers in Norway explore fire and explosion hazards at seven BESS installations

in a new paper accepted by the journal Future Batteries, and conducted as part of the research project SafeBESS, funded by the Research Council of Norway, a group of researchers audited seven active battery sites in Norway.

The researchers, which include members of independent research organization SINTEF, conducted physical walk-throughs and site inspections in Oslo, Bergen, and Trondheim alongside the building owners/facility representatives, and further reviewed documentation and reports.

Of the seven sites, ranging from kindergartens to offices, and installations in size from 41 kWh to 450 kWh, real-world commercial and industrial projects were shown to have significant inconsistencies.

Although much of the technology in use at the sites would be considered outdated by industry, most utilizing NMC cells versus industry-standard LFP cells, the hazard identification processes detail numerous basic failures, making it important for policy, safety standards, and for EPCs.

Compliance issues

Of the seven, none fully complied with NFPA 855 requirements for spacing, requiring 0.9 meters between units to limit fire propagation between modules. In terms of failure detection, just one site had gas detectors, two had explosion control, and six relied on smoke detectors, missing early warning potential due to off-gassing ahead of potential thermal runaway.

Several of the sites (noted as Cases 4, 5, 6, and 7) made use of repurposed Nissan Leaf batteries, with the researchers finding aside from Case 4, “no information could be retrieved from the battery supplier on resistance to cascading events inside the battery module.” Battery modules in Case 2, Case 3, Case 4 had “documentation of being certified according to UL 9540A but gave no information of testing carried out at cell, module or unit level”.

The paper doesn’t suggest that developers or EPCs enact certain approaches. However, the paper does highlight that verified propagation testing and adequate spacing are basic components of passive containment of any potential fires. The passive containments were further inadequate, and active detection such as gas detection was not sufficiently used.

Vulnerabilities in standards and understanding

The study notes that the cases are not statistically representative of Norwegian or international BESS deployments. However, they reveal “recurring vulnerabilities relevant beyond the specific installations studied”.

It goes on, “A likely cause of these major differences in fire and explosion safety measures is that Norway operates with performance-based regulations, combined with the limited knowledge of fire and explosion hazards associated with the use of LIBs. This is exacerbated by a lack of consistency between Norwegian and international standards on fire and explosion safety measures for BESS installations in buildings.”

In addition, the paper adds, “[D]ifferences [between Cases] were mainly driven by project-specific design decisions and differing interpretations of performance-based regulations and guidelines.”

The complete study, currently an in-press pre-proof, is available online in the journal Future Batteries.