Solar panels are becoming an increasingly familiar sight on homes, warehouses and industrial buildings across the UK. As deployment grows, however, so does the need to understand where fire risks can develop across a photovoltaic (PV) installation.
New research from business insurer QBE provides some useful insights. Data collected through Freedom of Information requests to UK fire and rescue services recorded 212 fires involving solar panels in 2025, compared with 91 in 2022. That’s an increase of 133%, while the number of installations grew by 52% over the same period.
In 2025, DC cabling and connectors were the leading recorded cause, accounting for 49 incidents. Solar panels themselves accounted for 36, followed by battery banks with 23 and inverters with 19.
So, when considering solar fire safety, should we be looking beyond the panels?
A solar installation is an electrical network
A PV installation is far more than the visible panels. Behind them sits an extensive network of DC cabling, connectors, inverters and other electrical equipment, often distributed across a large area.
The QBE research points towards loose connections, damaged wires and faulty wiring as potential causes of arc faults and other electrical failures. The insurer recommends particular attention is paid to the quality of DC cabling and connectors during commissioning and servicing.
This becomes particularly relevant on commercial and industrial rooftops, where the scale of the installation can make monitoring more challenging. QBE recorded 48 fires involving solar panels at commercial properties in 2025, up from 33 the previous year. With industrial incidents increasing from six to 14.
Inspection and good maintenance are clearly important. But they raise another question: what is happening between inspections?
Seeing what happens between inspections
A scheduled inspection or thermal survey provides valuable information about the condition of an installation at the time it’s carried out. Electrical equipment, however, continues operating long after the engineer has left the site.
A connection can deteriorate. Operating conditions can change. A localised area can begin behaving differently from the rest of the installation.
This is where continuous temperature measurement can add another layer of information.
Distributed Temperature Sensing (DTS) uses a fiber optic sensing cable to measure temperature continuously along its route. Rather than relying on individual measurement points, the system produces a temperature profile across the monitored area, allowing operators to see where temperatures are changing.
With Bandweaver’s FireLaser Linear Heat Detection system, that continuous measurement is combined with RapidScan intelligent alarm technology. Rather than relying on a single maximum temperature, RapidScan uses complementary alarm methods to identify different patterns of thermal risk, including sudden temperature increases and localised hotspots that behave differently from the surrounding area.
For a PV installation spread across a large rooftop, knowing that something is getting hotter is useful. Knowing where it’s happening makes that information actionable.
What does that look like on a real PV installation?
Bandweaver has already seen the value of this approach on a rooftop PV project in the Netherlands.
In 2023, a technical solutions integrator was looking for a fire detection and monitoring system for a high-value operational facility. The end user wanted coverage of areas susceptible to electrical overheating across its rooftop PV infrastructure. With components distributed across an open roof, conventional point-type detectors were considered unsuitable for the application.
Bandweaver’s authorised Dutch distributor, SenseTek B.V., worked with the integrator to develop the solution. One of the requirements was to demonstrate that the system could detect overheating behind the PV cable wiring, and Bandweaver’s FireLaser DTS was selected.
The importance of monitoring the wider electrical infrastructure, rather than concentrating solely on the PV modules, is particularly relevant in light of the latest QBE figures. Faulty wiring, connector failures, combiner box faults and overheating plugs are all recognised risks within PV installations.
It’s a useful example of how the conversation around solar fire protection can move beyond simply detecting an established fire.
Fire detection and condition monitoring are becoming closely connected
Temperature data can tell us something before there are flames or smoke.
If a connector, cable or piece of electrical equipment begins operating at an abnormal temperature, identifying that change gives the operator an opportunity to investigate. In some cases the cause may be benign; in others it may point towards a component that requires attention.
The way that change is identified matters too. RapidScan Adaptive Rate of Rise can respond to an abnormal increase in temperature without waiting for a critical temperature threshold to be reached, while Hotspot Detection identifies localised heating by comparing temperatures within the monitored area. For electrical infrastructure such as connectors and cable routes, this provides another way of recognising unusual thermal behaviour as it develops.
That doesn’t remove the need for good installation practice, electrical protection, routine inspection or maintenance. Continuous monitoring works alongside those measures, providing information about the asset while it’s operating.
There is an operational benefit to this as well. An abnormal temperature doesn’t necessarily need to become a fire before it matters. Overheating electrical equipment can indicate a developing problem that may ultimately result in damaged components, reduced reliability or unplanned downtime.
This changes the role of temperature monitoring. The value isn’t only in having continuous temperature measurements across the installation, but in how that information is used. Combining distributed measurement with intelligent alarm functionality can help operators recognise abnormal thermal behaviour, locate where it’s happening and decide when further investigation is needed.
Looking beyond the panel
The number of PV installations in the UK passed two million in 2026, and further growth is expected as solar plays a larger role in the country’s energy strategy. QBE’s latest figures are a timely reminder that fire safety needs to develop alongside that growth.
The panels themselves are only part of the picture. Cabling, connectors, inverters and associated electrical infrastructure all need to be considered when assessing how a PV installation will be monitored throughout its operating life. Periodic inspection remains an important part of that process, but continuous temperature measurement can provide visibility into what happens in between. When that measurement is combined with alarm methods designed to recognise different types of thermal behaviour, operators have another layer of information to help identify and locate developing problems.
For large and distributed installations, that additional information could help operators find a developing hotspot while it’s still a maintenance issue rather than waiting until it becomes a fire incident.
Find out more about Bandweaver’s fiber optic fire detection and temperature monitoring solutions.