Solar Safety: what goes wrong, and what your quote should show

The numbers are going the wrong way. UK fire services attended 91 fires involving Solar panels in 2022, 131 in 2023, 155 in 2024 and 212 in 2025, up 133%. Over the same years the number of installations grew by 52%. So fires are rising more than twice as fast as installations.

There's no routine national count of Solar fires. Official figures appear only in occasional Home Office releases, and the detailed year-by-year picture came out because an insurer, QBE, asked the fire services directly under Freedom of Information. In 2025, 88 of those fires spread beyond the installation itself.

The UK's government-commissioned study by BRE (2017) looked at more than 50 Solar fires. Installer error was the most common cause: problem installations 36%, faulty products 12%, system design 5%, and the rest had no single clear cause.

In the 2025 fire-service figures, the biggest single cause was DC cabling and connectors (49 fires), ahead of the panels themselves (36), Battery banks (23) and inverters (19). DC is the side between the panels and the inverter, and it's live whenever there's daylight.

The BRE study found the same pattern: DC isolators (the roof-side off switches) were linked to up to 18 incidents and DC connectors to 10. A common thread was electrical arcing, a spark across a gap where parts have worked loose or were never properly joined.

One thing I always ask about is connectors from different makers pushed together. They can look identical and still not be a true match. Stäubli, who make the original MC4 connector, say plainly that their connectors may not be mated with other makers' connectors, and that doing so loses their safety certification. MCS installers must fit equipment to the manufacturer's instructions.

BSI has published a specification on exactly this: PAS 63100:2024, on protecting homes against fire from Battery storage. It isn't a British Standard or a law in itself, but it's the nationally agreed specification. It says that, where practicable, Batteries should be installed outdoors. It rules out bedrooms, escape routes (landings, stairs, hallways), lofts and roof voids, and cellars with no outside access. A garage can be fine, with limits on how big the Battery is and protection from knocks.

If your quote just says "Battery, installed", ask exactly where it will go, and why there.

Put these five questions to your installer before you sign:

1. Are you MCS certified, and will I get an MCS certificate? (The insurer behind the fire figures advises using MCS-accredited installers.)
2. Where will the DC isolators go, and what are they rated for?
3. Will every DC connector pair be the same make and model?
4. If there's a Battery: where exactly, and how does that fit the fire-safety guidance above?
5. Which certificates and test results will I get at handover?

Not sure about the answers? Send me the quote and I'll check it for free. Safety is the first thing I look at.