No dedicated UK law governs BESS fire safety yet. Here’s what NFCC and NFPA guidance requires, what’s driving the risk, and how detection strategy fits in.
In May 2026, a fire broke out at Rufford Colliery in Nottinghamshire, one of the UK’s oldest grid-scale battery storage sites, after a short circuit in ageing nickel manganese cobalt (NMC) battery cells triggered rapid off-gassing that outpaced the site’s containment systems. It wasn’t an isolated incident. As the UK races to expand battery energy storage capacity to meet its clean power ambitions, growing pains like this one are raising real questions about how ready the sector is.
There’s currently no dedicated UK law governing BESS fire safety — but a patchwork of industry guidance is doing the heavy lifting instead, and it’s changing fast. This blog looks at why BESS fires behave differently from conventional fires, what’s currently governing safety on site, what’s driving the risk, and how effective detection strategy fits into all of it.
Why BESS Fires Are Different to Regular Fires
These fires are caused by thermal runaway — an uncontrollable, self-sustaining heating loop inside a battery cell that begins when a fault or damage causes a cell to generate heat faster than it can dissipate it. The main triggers include:
- Mechanical damage
- Electrical abuse
- Thermal abuse
Once the temperature inside the cell reaches roughly 150–180°C, the chemical components begin to decompose, and the cell starts to break down.
A single BESS unit contains thousands of tightly packed cells. When one cell overheats and enters thermal runaway, it radiates heat into the cells around it — a process known as thermal propagation. Once started, these fires are hard to stop, because they break the traditional “fire triangle”: the principle that fires need fuel, heat and oxygen to burn.
When a lithium-ion battery breaks down, the chemical reaction inside the cell generates its own internal oxygen supply, meaning the fire doesn’t rely on external oxygen to keep burning. Because the reaction is a deep chemical breakdown rather than a surface-level burn, these fires are much harder to extinguish — water often can’t reach the reaction happening inside the cell.
Current UK Safety Landscape
Currently, there is no dedicated UK law governing the fire risks posed by BESS sites. A private member’s bill was introduced with the aim of making local fire and rescue authorities statutory consultees for BESS planning applications — meaning fire services would have to be notified before new sites went ahead. However, the bill failed to progress before Parliament was prorogued, so it never became law.
In the absence of legislation, industry guidance is doing the heavy lifting in shaping how BESS safety is managed. The National Fire Chiefs Council (NFCC) has addressed many of the gaps through its planning guidance for fire and rescue services, which recommends a minimum distance of 30 metres between BESS cabinets and occupied buildings — increased from the previous 25 metres — while allowing spacing between individual cabinets to be reduced to as little as 0.914 metres where testing, such as UL 9540A, demonstrates that a fire can be contained to a single unit. Developers are also expected to identify all sensitive receptors within a 1km radius of a site and assess the potential impact of an incident on them.
The Department for Energy Security and Net Zero (DESNZ) provides further guidance covering the design, transport, installation and decommissioning of BESS sites. Meanwhile, NFPA 855 — a US standard — has become a de facto benchmark used across the industry, including in the UK.
With no overarching law in place, responsibility sits heavily with operators and developers, who have to be proactive about ensuring their sites have the most effective detection systems in place.
What Is Driving the Risk
The UK’s battery storage fleet needs to grow substantially to meet the government’s clean power ambitions. The Clean Power 2030 Action Plan expects installed BESS capacity to increase roughly five to sixfold, from 4.5 GW in 2024 to between 23 and 27 GW by 2030. To manage this growth, the National Energy System Operator (NESO) has overhauled the grid connection queue, moving away from a first-come, first-served model towards one that prioritises projects that are ready to build.
Growth on this scale is essential to meeting net zero goals, but it needs to be matched by safety systems that keep pace. There is currently no single register tracking every BESS-related fire in the UK, which makes it difficult to say precisely how common these incidents are — itself a sign that regulation hasn’t fully caught up with deployment.
Overall, it isn’t the technology itself that’s inherently dangerous — it’s the pace of development running ahead of standardisation. Older NMC battery chemistry, inconsistent site design, and detection systems that vary from project to project all contribute to the risk.
Detection and Mitigation: Where Protex Fits In
If standardisation is still catching up, detection strategy is one of the few things operators can control right now — and get right.
Thermal runaway rarely begins as visible fire. It starts as a silent internal chemical reaction that generates off-gassing — releasing hydrogen, carbon monoxide, carbon dioxide and vaporised hydrocarbons — often minutes to hours before any flames or smoke appear. Specialist gas detectors, calibrated to identify these specific compounds, can catch this early stage and give operators a critical window to isolate the affected unit before it escalates.
Because utility-scale BESS units are typically housed in sealed, weatherproof containers, conventional smoke detectors are notoriously unreliable in this environment — they rely on natural airflow to carry smoke to the sensor, which sealed enclosures don’t provide. Aspirating smoke detection, which continuously draws air samples through a network of sampling pipes, is far better suited to picking up very low smoke concentrations early inside an enclosed space — and it’s a technology already proven across other high-risk sectors, from offshore platforms to oil and gas facilities.
The same principles behind Fire & Gas mapping on those sites apply just as well to BESS: detector placement and coverage need to be validated against the specific hazard on site, not assumed from a generic layout.
Detection systems do more than just detect and help prevent fires — they provide fire and rescue services with critical, real-time data before crews even arrive on site, supporting the kind of fast, informed decision-making that effective BESS incident response depends on.
What Operators and Developers Should Do Now
With standards and guidance evolving quickly — and no single law to fall back on — the most effective approach is to build fire and gas safety into a BESS site from the earliest design stage, rather than treating it as an afterthought. In practice, that means:
- Engaging the local fire and rescue service early in the planning process, rather than waiting until an application is submitted
- Reviewing detection and containment strategy against the latest NFCC guidance and NFPA 855 requirements, since both are updated regularly
- Carrying out Fire & Gas mapping specific to the site’s layout and battery chemistry, rather than relying on a generic template
- Choosing detection technology suited to sealed, weatherproof enclosures, rather than systems adapted from conventional building fire safety
Waiting for legislation to catch up isn’t a strategy — proactive design is.
How Protex Systems Can Help
Battery storage is central to the UK’s clean power ambitions, but its safety framework is still taking shape. Protex Systems works with operators and developers across high-risk sectors — including battery storage — to design fire and gas detection systems tailored to the specific hazards on site.
Get in touch with our team to discuss your BESS fire and gas detection strategy.
