Solar power has become an increasingly important part of the UK energy mix. For businesses, schools, warehouses and other large sites, rooftop solar can cut electricity costs and reduce reliance on the grid, while making use of roof space that would otherwise sit unused. But new research from business insurer QBE raises an issue that building owners and facilities teams need to take seriously: solar panel fires are increasing significantly faster than the number of installations. The growing risk of solar panel fires means that good solar panel installation and maintenance really matter.
According to data obtained by QBE through Freedom of Information requests to UK fire services, there were 212 fires involving solar panels in 2025, compared with 91 in 2022. That’s an increase of 133 per cent. Over the same period, the number of UK solar installations increased by 52 per cent, rising from approximately 1.27 million to 1.93 million.
Solar itself should not be viewed as inherently unsafe. The figures do, however, reinforce something we regularly stress at Powercor: the quality of the design, installation and ongoing maintenance of a solar system matters enormously.
Solar panel fires in commercial buildings deserve particular attention
The QBE findings are especially relevant to commercial property owners.
Fires involving solar panels at commercial properties increased from 33 in 2024 to 48 in 2025, a rise of 46 per cent in a single year. Industrial properties recorded an increase from six incidents to 14 over the same period.
Those numbers need to be considered alongside the continuing growth of commercial rooftop solar. Warehouses, factories, offices, schools and retail buildings can provide large areas of roof space, making them attractive locations for photovoltaic systems.
On a large commercial installation there may be hundreds or thousands of panels, extensive DC cabling, numerous connectors, inverters and associated electrical equipment. Every component needs to be correctly specified, installed and maintained.
A fault on a commercial roof can also have consequences far beyond the solar installation. QBE found that the number of fires spreading beyond the solar system increased from 33 in 2022 to 88 in 2025. For a business, that introduces the possibility of building damage, interruption to operations and loss of access to important facilities.
Cabling and connections are the main cause of solar panel fires
One of the most useful findings from the research concerns where problems are occurring.
QBE reports that DC cabling and connectors were the leading identified cause of solar related fires in 2025, accounting for 49 incidents compared with 26 in 2024. Other reported sources included solar panels, battery banks and inverters.
That should focus attention on workmanship and inspection.
Solar arrays operate outdoors for decades. Cabling and connectors can be exposed to heat, cold, moisture, wind and movement. Connections that were poorly made at installation can create problems. Damage can also develop later through weather, deterioration, animals or work carried out elsewhere on the roof.
This is why the commissioning of a system should never be regarded as the end of the job.
Solar panels are low maintenance, not maintenance free
A well-designed solar installation is a long-term asset, but it still requires attention.
At Powercor, we recommend regular professional inspections to check components including electrical connections, cabling, mounting systems and inverters. Maintenance can identify water ingress, damaged cables, loose connections, deterioration and equipment faults before they become more serious.
For commercial sites, the maintenance programme should reflect the scale and environment of the installation. A large warehouse roof, for example, presents very different access and operational considerations from a small domestic array.
Owners should also know where isolation equipment is located and ensure it remains accessible. Documentation should be kept current, particularly when systems have been altered, extended or combined with battery storage.
QBE similarly recommends annual inspection, attention to DC cabling and connector quality, accessible firefighter switches and appropriate arc fault detection. It also advises inspection following extreme weather events such as high winds, hail or flooding.
Getting solar right
The message from the QBE research isn’t to slow the move towards solar, but to raise expectations for how these systems are designed, installed and looked after.
Commercial solar has a major role to play in reducing electricity costs and carbon emissions across UK buildings. Poor workmanship and neglected maintenance put those benefits at risk.
For organisations investing in solar, choosing competent installers, using appropriate equipment and establishing a proper inspection regime should form part of the project from day one.
A solar installation may sit on the roof and largely out of sight, but it remains an active electrical system for decades. Treat it accordingly.
Battery storage is becoming a more common addition to solar projects because it allows organisations to retain generated electricity and use it when demand is higher.
Its location and installation need careful thought.
QBE points to the risk of thermal runaway in lithium ion batteries, where damage, overheating or other faults can cause a battery to heat uncontrollably. It recommends that battery systems are installed in well-ventilated locations with suitable access for inspection and emergency response.
For businesses considering solar and battery storage together, the complete system should therefore be designed as one electrical infrastructure project, rather than treating the battery as a simple addition.
Why energy monitoring matters
The message from the QBE research isn’t to slow the move towards solar, but to raise expectations for how these systems are designed, installed and looked after.
Commercial solar has a major role to play in reducing electricity costs and carbon emissions across UK buildings. Poor workmanship and neglected maintenance put those benefits at risk.
For organisations investing in solar, choosing competent installers, using appropriate equipment and establishing a proper inspection regime should form part of the project from day one.
How can Powercor help?
A solar installation should be treated as a long-term asset and our solar maintenance programmes and ongoing support provide peace of mind and mitigate your risk of fire.
The risk of solar panel fires means good solar panel installation and maintenance really matter.
Powercor works across solar, battery storage, electrical infrastructure and energy efficiency, giving businesses the opportunity to look at the complete electrical picture rather than treating solar as a standalone technology.
Figures and fire incident data referenced in this article are sourced from research published by QBE European Operations in 2026, based on Freedom of Information requests to UK fire services and UK Government solar photovoltaic statistics.
