Fire risks in solar power and battery systems – a guide to protect your property

Power Generation

As businesses begin to get on board with renewable energy, whether fuelled by cost savings, ESG credentials or environmental sensitivity, we are seeing an upsurge in the installation of solar panels and associated systems. Indeed, more than 190,000 were installed in 2023 (Source: Riskstop).

However, although they bring many benefits, there have been reports of solar panel related fires rising by sixfold in the last few years (Source: The Independent). As it is an electrical system and there are a lot of wires, pests such as pigeons and rats are quite common visitors to the delicate wiring and framework of the panels if this is not protected in some way (usually wire mesh and grilles).

One of the issues is that if a fire does occur, the panels can go on continuing to produce electricity whilst the fire is in progress. If you add in melting wires from the heat of the fire, resultant short circuiting and a fire brigade spraying cold water over everything including live electricity production, it can get very dangerous indeed. This can also include electrocution of fire brigade staff and a high possibility of fatalities.

The message here is that solar panel systems need to be maintained, much as any other business machinery. This will include regular testing under the fixed wiring rules (Electricity at Work Regulations) and there are other specific care and maintenance routines tailored to an individual system which must be carried out by a competent and accredited NICEIC technician.

Reports carried out by accredited engineers will include detailed highlighting of any issues, categorised based upon how serious they are and how urgently they need to be fixed. Immediate danger will require quick action.

Insurers are also beginning to get on board with this and are starting to develop their own guidelines, most of which are broadly similar. However, they are still a bit thin on the ground.

Batteries

One of the associated issues with solar electricity production is what to do with it when you are not using it and what to do when the sun goes down. This has been addressed in part by the availability of battery systems. These store excess energy that you produce and keep it in batteries for use overnight or in bad weather. The usual type of battery is a lithium ion one and, in some cases, they may have many banks of these in operation.

As you may have seen from our previous bulletins, lithium ion batteries have a nasty tendency to catch fire, often when on charge. This fire is a chemical fire and as such, cannot effectively be put out. The most common ones seen on social media seem to be those of electric bikes, electric vaping machines and, of course, electric cars. In most cases, the device is a write off following a dramatic fire and sometimes explosion.

Fortunately, commercial battery systems, although still vulnerable in exactly the same way as the smaller battery types, are far more robustly designed and manufactured to help prevent these fires.

Fire protection strategies

Fire protection strategy for lithium ion fires has evolved significantly recently and will now look at pre fire conditions and how they lead to an increasing chance of thermal runaway (the self-promoting chemical lithium ion fire), the fire itself and the cooling and prevention of fire spread strategies to close the matter off.

Strategies will commence with design and materials selection and may then progress to gas detection to determine that there is a possibility that an event is about to happen. This may be linked to temperature detection and of course, eventually, fire detection. Once the fire is established, given that they are extremely difficult to extinguish, priority is given to cooling, prevention of spread and stopping further thermal runaway. Finally, there is the environmental issue of what to do with what is left after the fire. This will include consideration for disposal of contaminants.

Units will often contain multiple sensors to detect anomalies with appropriate alarms as necessary. These can trigger automatic shutdowns and signal the site operators in an instant. Some will even include things like a hose attachment allowing the fire brigade to connect a hose to flood the battery directly with water to cool it and reduce the thermal runaway potential.

If considering the installation of solar power to your business, be aware that insurers may ask around any or all of these questions and quite a few more in respect of design and specification. The easiest way to manage this is to put the proposed specification in front of the insurers at design stage so their fire surveyors can comment on it accordingly. It is usually far easier to design an improvement in before the construction stage than after the work has started.

Please contact our team of risk management specialists for any further information on this subject.