Energiforsk 2026-1163 Batterienergilagring Konsekvensbedomning (2026)

Energiforsk Rapport 2026:1163 — Batterienergilagring i litiumjonbatterier: Konsekvensbedömning av explosion och spridning av toxiska förbränningsprodukter (Brandskyddslaget, March 2026, 132pp, ISBN 978-91-89918-46-7). A methodologically detailed consequence-assessment study, funded by the same Energiforsk programme (Risk- och tillförlitlighetsanalys 2021–2025) as the wiki’s other fire-safety source (Source - Energiforsk 2025-1148 Syntesrapport Risk Och Tillförlitlighet (2025)) — narrower in scope (explosion and toxic-dispersion consequence assessment specifically) but deeper on methodology. Raw copy: Raw/Energiforsk-2026-1163-BESS-fire-safety.pdf (+ -extracted.txt).

Summary

Addresses two risks from lithium-ion BESS: gas explosion during thermal runaway, and dispersion of toxic combustion products during fire. Methodology: five-part literature review, industry workshop, analysis of real incidents, and parameter studies using established standards (NFPA 68, SS EN 14994 for explosion venting; PM10/VOC/HF modelling for toxic dispersion).

Key findings:

• Deflagration events can produce pressure effects and debris zones (kastzon) up to ~25 m (the conclusions state zones of up to 25 m “have been established in a number of cases” in real incidents; the damage area from flames ejected during deflagration is put at <30 m). A recurring factor in those incidents was the absence of correctly dimensioned pressure relief.
• Harmful concentrations of toxic combustion products are typically confined to the immediate vicinity (<30 m in the abstract). The conclusions put it at roughly 10–20 m from the fire source based on experience from the incidents studied, and the back-cover summary states both explosion and toxic effects as “normally no more than local (10–20 m)”. Conservative dispersion models, by contrast, can give theoretical distances of hundreds of metres; the report says model distances should be read as indicative guide values, not exact forecasts. Studied scope: large stand-alone outdoor systems only — indoor placement, smaller (residential, V2X, UPS) installations and off-gassing-only (“smoking”) releases were not studied.
• Dispersion models tend to overestimate consequence distances when conservative assumptions ignore thermal buoyancy and chemical reaction behaviour in the smoke plume.
• BESS should not be treated as inherently high-risk facilities when properly designed and operated — but documented risk analysis, correctly dimensioned pressure relief (per NFPA 68/SS EN 14994), adequate separation distances, robust detection, and coordination with the local rescue service (räddningstjänst) are essential. The report also stresses substantial uncertainty in input data (gas production and composition) and recommends combining probability-reducing measures (e.g. mechanical ventilation) with consequence-limiting ones (pressure relief, separation distance); it notes NFPA 855 edition 2026 now requires emergency ventilation per NFPA 69 plus an NFPA 68 evaluation, where the 2023 edition allowed a choice. It judges toxic-spread risk to third parties not materially greater than for other fires.
• Appendix A provides practical design/procurement guidance for facility owners and operators.

The gap this report itself confirms is still open: future work should include validating venting models for actual battery-gas mixtures, studying dispersion during “smoking” thermal runaway (off-gassing without external combustion), and — explicitly — developing harmonized national guidelines with clear acceptance criteria, which do not yet exist in Sweden. This is the same absence the wiki’s earlier Energiforsk source (2025:1148) identified; this report (published March 2026) again describes the absence of harmonized Swedish regulation as a source of significant uncertainty.

Relevance to wiki topics