Fire Protection for Super Batteries

February 19, 2026

Battery storage systems are booming. Larger and larger facilities are being planned, connected to the grid, and are gradually advancing the energy transition. Yet media reports repeatedly highlight battery storage fires. How dangerous are these XXL batteries really, and what measures can prevent or contain fires? We spoke about this with Jan Struve, fire protection expert at TÜV NORD.

#explore: Mr. Struve, in January 2025 a fire broke out at one of the largest battery storage facilities in the world, in California. How often do such fires occur?

Jan Struve: Generally speaking, relatively rarely. However, when they do occur, they appear correspondingly dramatic due to the size of the flames. This produces spectacular images that the media are keen to pick up because they attract significant public attention—also because this is a relatively new technology. We observed the same phenomenon in the early days of electric vehicle fires.

When batteries catch fire, they are considered difficult to extinguish. Why is that?

How easily a battery cell ignites and how difficult it is to extinguish always depends on the type of battery. In widely used lithium-ion batteries based on nickel-manganese-cobalt, a short circuit can trigger a chemical reaction that releases a large amount of heat that cannot dissipate—this is known as thermal runaway, which can quickly spread to other cells. Flammable gases are also produced, which can cause flash fires if ignited. Since this type of battery also releases oxygen during the reaction, such fires are difficult to fight using conventional methods.

How can these fires be fought instead?

In practice, a battery module that has gone into thermal runaway is almost impossible to extinguish. Therefore, the best option for fire brigades is to cool the fire—or the surrounding modules and units—with water. However, this presents two additional challenges. The individual battery modules are usually integrated into containers similar to those used in shipping. Firefighters may not be able to access the source of the fire directly, especially since they must maintain safety distances because the batteries may still be live.

At the same time, thermal runaway causes the temperature in the cells to rise exponentially. Beyond a certain point, water can no longer cool them sufficiently. As a result, firefighting strategies have shifted: since the burning container usually cannot be saved anyway, it is allowed to burn in a controlled manner. The extinguishing water is then used to cool the surrounding battery containers to prevent the fire from spreading.

What legal requirements apply to fire protection for large-scale storage systems?

In Germany, there are no fire safety regulations that explicitly address battery storage systems. Requirements generally arise from building regulations, which define specific protection goals: people must be able to escape from or be rescued from the facility; the fire must not spread to neighboring buildings, which requires appropriate spacing; and the fire brigade must be able to extinguish the fire.

In large battery storage facilities, there are typically no people present, so requirements for escape routes do not apply. If they are located in open fields, there are usually no neighboring buildings that could be affected.

Since battery storage systems can be considered structural installations, the distances of five or 2.5 meters specified in building regulations do not directly apply to the spacing between containers. However, to prevent fire spread through adequate spacing, manufacturers already conduct full-scale fire tests on battery containers. This allows them to determine the heat radiation of a specific container and optimize the arrangement of containers within the battery park accordingly.

What requirements must be met for fire brigade operations?

Access roads must be provided, and sufficient extinguishing water must be available. If these requirements are met—ensuring that people and neighboring infrastructure are not endangered in the event of a fire—approval can be granted. Any additional protective measures are coordinated by operators, particularly with insurance companies, which may impose further fire protection requirements to reduce their risk.

In addition to fire safety assessments for the approval process, you also develop comprehensive fire protection concepts that go beyond regulatory requirements. How do you approach this?

We consider all aspects, starting with the type of batteries to be used: are they types that produce a lot of oxygen in the event of a short circuit or not? A powerful battery management system is essential as a preventive measure. It detects early on if something is wrong with a battery module so it can be replaced proactively.

Such systems have become increasingly advanced and intelligent over the years. This has already led to fewer battery fires today and fewer storage systems failing due to defects—which is, of course, of major economic interest to operators.

What measures can detect and fight fires at an early stage?

Fire alarm systems are a common means of automatically and immediately notifying the fire brigade, even during the early stages of a developing fire. Sensors that measure gas concentrations inside the container are also useful. If, in the event of damage, the liquid electrolyte in the battery decomposes and releases gases, an explosive atmosphere can develop. This can be prevented by linking these sensors to an automated ventilation system.

The next level of protection can be fire suppression systems inside the container, which can contain a fire as much as possible in its early stages until the fire brigade arrives. Particularly important is the aforementioned shift in firefighting strategy—focusing on cooling neighboring containers to prevent fire spread. That is why we always recommend involving local fire brigades during the approval process and, if necessary, initiating or supporting additional training. In short, it is a bundle of interlocking measures whose implementation we ultimately review.

 

Are there technological or regulatory developments aimed at further reducing fire risks in the future?

In addition to advances in battery management systems, new battery types are playing a major role—namely lithium iron phosphate batteries, which are increasingly being used today. These are thermally more stable and release less oxygen. This reduces the risk of overheating, thermal runaway, and consequently fire.

There is also experimentation with special intumescent materials that absorb part of the heat energy in the event of a fire, giving firefighters more time to intervene. From a regulatory perspective, the EU Battery Regulation obliges manufacturers to further improve the safety of their batteries, which also benefits the fire safety of battery storage systems.