BESS Safety Standards in Europe: What the 2025 Updates Mean for Project Permitting
Battery Energy Storage Systems above a certain threshold require fire safety assessment, hazardous area classification, and — in most European jurisdictions — formal approval from the local fire authority before commissioning. The specific requirements vary by country, but the direction of regulatory travel is consistent: standards are tightening, and the approval process is getting longer.
For projects currently in development or approaching commissioning, understanding where the standards changed in 2025 is directly relevant to timeline and cost planning.
The EN IEC 62933 series — what changed
The EN IEC 62933 series governs electrical energy storage systems including BESS. Part 5-2, covering safety requirements for grid-connected systems, was updated in 2024 and is being adopted across Member States throughout 2025 and 2026.
The key changes for utility-scale BESS:
Prescriptive Thermal Runaway Detection: The updated standard introduces more prescriptive requirements for thermal runaway detection and suppression. Previous editions allowed a range of approaches to early detection. The 2024 update specifies minimum performance criteria for gas detection systems — specifically hydrogen and carbon monoxide — as early indicators of cell degradation before thermal runaway occurs.
Increased Separation Distances: Separation distances between battery modules and between battery containers have been revised upward in the fire safety annexes. Projects designed to previous separation standards may require layout modifications to achieve compliance, particularly those using high-energy-density lithium iron phosphate (LFP) configurations.
Extended Testing Metrics: Testing documentation requirements have been extended. Suppliers must now provide third-party test reports for the complete battery system as installed — not just the cell chemistry — including fire propagation tests and short-circuit tests at the system level.