Solar panel fires resist extinguishing, substation fires spread fast, lithium battery fires reignite on their own — three fire risks specific to renewables that the Fire Prevention, Firefighting and Rescue Law 55/2024/QH15 (effective 1 July 2025) regulates more tightly. Many investors still design fire safety like an ordinary factory and stumble at the design-approval stage.
Solar plants: where fires start
The most common ignition point is not the panel but the DC electrical system: loose MC4 connectors and intermittent DC wiring cause electric arcs — DC arcs do not self-extinguish like AC, easily becoming fires spreading along panel rows. Fire requirements: standards-compliant electrical design, arc-fault detection and interruption (AFCI) for large systems, firefighting access roads between panel arrays, and site-wide emergency power cut-off plans.
Firefighting note: sunlit panels still generate power even with the inverter disconnected — firefighters must be trained for energised systems, using mist spray rather than direct hose streams in some situations.
Substations and battery storage (BESS): the highest risk
Substations hold large volumes of insulating oil — oil fires spread fast with toxic smoke. Requirements: emergency oil containment pits, fire walls between transformers, suitable automatic suppression. Lithium-ion battery storage (BESS) is the newest risk: thermal runaway self-heats, reignites repeatedly, emits toxic gases — ordinary water is of limited effect.
For BESS, fire design approval demands: fire containment between battery modules, early gas and heat detection, ventilation against flammable gas build-up, safe distances to neighbouring structures, and detailed, drilled emergency response plans. This is the most scrutinised item in storage-equipped projects.
Fire design approval and acceptance procedures
Solar plants, substations and battery stores require fire design approval before construction and fire acceptance before commissioning under Law 55/2024/QH15. Without the fire acceptance document, operation is barred — and insurers may deny claims for fires at unaccepted facilities. Recommendation: bring fire consultants in at the basic-design stage, not at detailed design — late fire-design fixes cost multiples more.
This article has been quality-reviewed by the FLAW AI Legal Council.
Frequently Asked Questions
What fire-safety requirements apply to battery storage (BESS)?
Lithium-ion BESS carries thermal-runaway risk (self-heating, reignition, toxic gases) and faces the closest scrutiny: fire containment between modules, early gas and heat detection, ventilation against flammable gas build-up, safe distances to neighbouring structures, and drilled emergency response plans. Fire design approval and acceptance are mandatory.
How are solar panel fires fought?
The most common ignition is DC electric arcs from loose connectors — DC arcs don't self-extinguish like AC. When fighting fires, note that sunlit panels still generate power with the inverter disconnected, so firefighters need energised-system training and appropriate tactics instead of direct hose streams in some situations.
Can a power plant operate without fire acceptance?
No. These projects require fire design approval before construction and fire acceptance before commissioning under Law 55/2024/QH15. Operating without acceptance is a violation, and insurers may deny fire-damage claims.