Solar Panel Fire Risk UK

Solar panels can cause fires, and in the UK roughly one installation in every 9,100 was involved in a fire attended by a fire and rescue service in 2025. That comes from 212 incidents recorded across the UK in 2025, set against the 1,933,268 solar installations the government counted at the end of that year. The rate is low. It is also rising faster than the number of installations, which is the part of the story worth your attention.

Below: the actual rate year by year, what the government's own forensic investigation found was catching fire and why, what the newest fire-spread research says about in-roof panels, and the specific things you can ask an installer before you sign.

How many solar panel fires are there in the UK?

UK fire and rescue services attended 212 fires involving solar panels in 2025, up from 91 in 2022. Those figures come from a Freedom of Information exercise run by the insurer QBE across UK fire and rescue services, published on 10 August 2026. It is insurer-obtained FOI data rather than an official national statistic, so treat it as the best available count rather than a definitive one.

The raw rise is 133% in three years. Over the same period the number of solar installations in the UK rose 52%. Those two percentages are how the story reached the newspapers, and on their own they are misleading, because a raw count of fires tells you nothing without the number of systems that could have caught fire.

So here is the division. The installation counts below are taken directly from the Department for Energy Security and Net Zero's Accredited Official Statistics spreadsheet (Energy Trends table 6.3, published 30 July 2026), not from the press coverage. The rate column is our own arithmetic.

The rate per installation went from 7.2 to 11.0 per 100,000 in three years. That is a 53% increase in the chance that any given system is involved in a fire in a year. Growth in installations does not explain the rise away, which is the honest reading of the data and the one the industry should be uncomfortable with.

It is still a small number. Two things can be true at once: your individual risk is low, and the trend is going the wrong way.

What is the risk for a home with solar panels?

Of the 212 fires in 2025, 102 were at residential properties. The rest were 48 at commercial buildings, 14 at industrial buildings and 14 at solar farms.

DESNZ counted 1,626,567 domestic solar installations in the UK at the end of 2025, and 1,444,043 a year earlier. Take the midpoint as the rough number of homes exposed through the year, about 1.54 million, and 102 residential fires works out at roughly 1 in 15,000 homes with solar per year, or 6.6 per 100,000.

Two caveats on that figure, because it is our calculation rather than a published statistic. QBE's "residential" classification and DESNZ's "domestic" category are not guaranteed to be drawn on the same line. And a count of fires during a year is being divided by a stock of installations measured at year end, so the true exposure sits somewhere in the middle. Treat 1 in 15,000 as an order of magnitude, not a decimal place.

For scale, the Home Office recorded 26,180 dwelling fires attended by fire and rescue services in England in the year to March 2026, of which 23,795 were accidental. Even comparing a UK-wide solar number against an England-only dwelling number, which flatters solar, English fire services attended around 250 dwelling fires for every one UK residential fire involving solar panels.

What actually catches fire on a solar installation?

Not the panels. The DC electrical components between the panels and the inverter. The most detailed UK evidence on this is a forensic study the government itself commissioned: BRE National Solar Centre report P100874-1004, "Fire and Solar PV Systems, Investigations and Evidence", Issue 2.9, dated 11 May 2018 and prepared for what was then BEIS. The team built a database of 80 unique incidents, 26 of them investigated on site shortly after the fire and 7 involving laboratory examination of the burnt components.

The report's Table 6 records which component the fire started in. "Probable" is the team's assessment on the evidence; "possible further" covers incidents where that component may also have been the origin:

One component dominates. In the report's own words, "DC isolators were found to present the greatest fire risk within the database of incidents. Approximately 30% of the incidents recorded in this study were caused by malfunctions within this component."

A note on the numbers, because lower figures circulate. The International Fire and Safety Journal, on 24 April 2026, reported the BRE work as having "reviewed more than 50 solar PV fire incidents" and found that "DC isolators were linked to 18 fires, while DC connectors caused 10 incidents, and inverters were responsible for 7 more". Those are not the figures in Table 6 of Issue 2.9. The most likely explanation is that they come from an earlier interim edition of the same multi-year project, which reported on a smaller database before it was completed. Issue 2.9 of May 2018 is the final version, and its table is the one reproduced above.

The panels themselves account for 2 probable incidents out of 45. Whatever your instinct says when you look at a roof full of glass, the glass is not the problem.

Why do DC isolators catch fire?

Because they are usually mounted outside, they fill with water, and water plus several hundred volts of direct current produces an arc. BRE found isolators "mounted on an exposed exterior wall" that "were filling with water", and traced the ingress to cable glands facing upwards on the top surface of the enclosure, sometimes with more than one cable forced through a single gland.

The report separates three distinct failure modes: isolators originally designed for AC being used on a DC circuit, which are "unlikely to be reliable over the life of a PV system"; isolators incorrectly specified for the current or voltage of the array, which it found in 2 cases; and poor installation practice, which it identified in 9 cases and describes as "the majority of DC isolator failures leading to fires or thermal events".

That is the crux of the whole subject. When BRE assigned a root cause across the incidents it could resolve, it concluded: "Approximately 36% of incidents recorded that were caused by PV systems were attributed to poor installation practices. 5% were attributed to faulty products and 10% to system design errors. The causes of the remainder were unknown."

In BRE's data, poor installation accounted for roughly seven times as many incidents as faulty products. The fire risk you can influence is largely the risk of choosing badly among installers, not among panels. Our guide to choosing an MCS-certified installer covers how to check credentials properly.

What the current MCS standard requires

The standard your installer works to now has clauses aimed squarely at the defects BRE found. MIS 3002, the MCS solar PV installation standard, exists as two current documents with different clause numbering, and both became mandatory on 18 June 2026. Version 6.0 applies to the current installer scheme; MIS 3002:2025 Version 2.0 applies to the redeveloped scheme. Both carry the same cover date of 18 March 2026. Clause numbers below are given as 5.x for V6.0 and 3.x for the 2025 document.

• Clause 5.6.5 (3.6.5) requires the Ingress Protection rating of every component to be maintained for its location, with a note that for external installations this "will require cable entry into the bottom of enclosures, use of a drip-loop, and a single cable per gland". Read that against the BRE finding on upward-facing glands with multiple cables and you are looking at the same defect, written into the standard as a requirement.
• Clause 5.6.7 (3.6.7) is one line long and worth quoting in full: "Where present, any arc fault detection function within the inverter shall be enabled." Arc fault detection is the feature that shuts a system down when it sees the electrical signature of an arc. If the inverter on your quote has it, the standard requires it be switched on.
• Clause 5.6.4 (3.6.4) requires DC plug and socket connectors to be "assembled with the correct tools and procedures to minimise the risk of failure", with a note that "use of incorrect tools for crimping and assembling of DC connectors has been identified as a significant contributing factor to connection failure and even fires".
• Clause 5.6.3 (3.6.3) says connectors "should be protected from water ingress for the lifetime of the system", and specifically that they should not be installed where they could stand in water.

Note the modal verbs. Clauses 5.6.4, 5.6.5 and 5.6.7 say "shall". Clause 5.6.3 says "should". In a standard, that difference is the difference between a requirement and a recommendation.

Are in-roof solar panels a higher fire risk?

The newest UK research says fire spreads further and is harder to put out on roof-integrated arrays than on panels mounted above the tiles. On 22 December 2025 the government published a summary of research carried out for the Building Safety Regulator by the Health and Safety Executive's science and research centre: 11 large-scale experiments on how PV panels affect fire spread over pitched residential roofs.

The findings, in the summary's own terms:

• Every sample with panels on it did worse than the control. "All samples which incorporated PV panels had greater flame spread than the control sample."
• Among above-roof (BAPV) systems, backsheet material mattered. Plastic-backed panels showed "significant vertical fire spread up the array". With glass-backed panels, "fire did not extend past the first PV panel".
• Roof-integrated (BIPV) systems "exhibited greater flame spread both horizontally and vertically" than above-roof systems, and every integrated sample "involved other roof elements in the fire including the roof battens, breather membrane and plastic support trays".
• The enclosed cavity under an integrated array made fires "significantly harder to extinguish", because the flames were "protected from water in the cavity".
• Mounting rails, positioned well, slowed spread by acting as a fire break.

This is test-rig research on deliberately ignited roofs, not a count of real incidents, and four further tests on fire penetration through integrated systems have been commissioned. It is not a reason to rule out an in-roof array. It is a reason to ask about backsheet type and the fire classification of the kit, which is already governed by boundary-distance rules in the standard. Our guide to in-roof solar panels sets out those rules and the MCS 012 testing regime in detail.

Has anyone been hurt by a solar panel fire in the UK?

Injuries in the BRE database were mostly minor, and no fatality in it was caused by a PV system. Across 80 incidents the report records "6 cases of smoke inhalation (treated at scene), 1 minor burn, 1 case of shock and 1 minor knee injury", and states that while there are "3 fatalities recorded in the database", "the fire has not been as a result of the PV system".

Severity varied. Of the fires that were caused by PV systems, 22 were classed as serious, meaning difficult to extinguish and spreading beyond the PV system. 36 were localised fires affecting only the PV components and the immediate area, or thermal events: smoking or smouldering that never became a fire at all.

BRE also flags that its own count is probably low, saying the team "strongly suspect a degree of under-reporting, especially amongst solar farms and domestic thermal events that were resolved by a solar installer/maintenance engineer". A smouldering isolator that an engineer quietly replaces never reaches a fire service, and so never reaches any of the numbers on this page.

Do solar batteries and diverters change the picture?

Battery banks accounted for 23 of the 212 incidents in 2025 in QBE's breakdown, and power diverters did not appear in BRE's database at all. QBE's 2025 causes split into DC cabling and connectors (49 incidents, nearly double the 26 recorded in 2024), the panels themselves (36), battery banks (23) and inverters (19).

On diverters, the BRE report addresses the rumour head on: "There are anecdotal reports of power diverters presenting new fire and safety risks... However, within this project, we have yet to encounter a fire that appears to have been caused by one of these devices, so the results so far do not support this assertion." Our page on solar power diverters covers whether one is worth the money in the first place, which for most gas-heated homes it is not.

Battery storage is a genuinely separate subject with its own standards and its own failure modes, and it is not covered here beyond that count. Our guide to solar battery storage covers the specification questions.

What to check before you sign a solar quote

Everything on this list is answerable in writing before any money changes hands. Given that installation quality drives roughly 36% of solar fires and product faults around 5%, these questions are worth more than any comparison of panel brands.

1. Is the installer MCS certified, and under which scheme? Ask which version of MIS 3002 they work to. Anyone who cannot answer that in 2026 is not paying attention to their own standard.
2. Where will the DC isolator go, and what is its IP rating? If it is going outside, ask them to confirm in writing that cable entry is into the bottom of the enclosure, with a drip-loop and one cable per gland, per clause 5.6.5 (3.6.5).
3. Does the inverter have arc fault detection, and will it be enabled? Clause 5.6.7 (3.6.7) requires it be turned on where the function exists. Get the answer on the quote.
4. How will the DC connectors be assembled, and where will they sit? Clause 5.6.4 (3.6.4) requires the correct tools and procedures for crimping, and 5.6.3 (3.6.3) says connectors should not be installed where they could stand in water. Both are reasonable things to have confirmed in writing.
5. Will the handover pack include the emergency shutdown procedure? Clause 6.2.1 requires a comprehensive document pack, 6.3.1 sets out what must be handed over and explained on the day, and 7.3 requires the documents to state the checks you should carry out yourself, how often, and what to do if you find a problem. The MCS maintenance schedule in Appendix F lists "Emergency shutdown procedure visible" as a check. Most homeowners have never seen theirs.

After the install, the checks that matter are unglamorous and mostly visual. The MCS maintenance schedule puts functional checks of the AC and DC isolators, inspection of DC junction boxes for damage and ingress, and checks that externally mounted inverters are free of signs of water ingress on the contractor, not the customer. Our page on solar panel maintenance sets out the full schedule and how often each tier applies.

What to do if you suspect a fault

If you smell burning, see scorching around the isolator or inverter, or hear crackling from the DC side, call your installer and treat it as urgent. In an active fire, call 999 and tell the control room the property has solar panels, because it changes how the crew approaches the roof and the electrics.

The important thing to understand about a solar array is that the DC side is live whenever there is daylight on the panels. Switching off at the consumer unit stops the AC side; it does not de-energise the cabling running from the roof. That is precisely why the emergency shutdown procedure in your handover pack exists, and why the sequence in it is worth reading once, on a calm day, rather than for the first time in an emergency.

So are solar panels a fire risk worth worrying about?

On the numbers, the risk to any individual home is small, and it is dominated by workmanship rather than by the technology. Around 1 in 15,000 UK homes with solar was involved in a fire attended by a fire service in 2025. The components that fail are the DC isolators and connectors, not the panels. Roughly 36% of the incidents traced to a cause came down to poor installation.

The trend deserves respect, though. A 53% rise in the rate per installation in three years is not explained by more panels existing, and an industry installing over 23,000 systems a month has a quality-control question to answer. The defence available to you as a buyer is the same one that has always worked: pick the installer carefully, get the answers in writing, and keep the handover pack.

If you want the wider financial picture, our guide to solar panel costs in the UK covers what a system costs and what it returns, and whether solar panels are worth it works through the payback maths.