Solar · Maintenance
Are solar panels a fire risk, and what should be inspected?
Short answer
Fires are rare, about 0.01% of UK installations in the BRE investigation, but most PV-caused fires started in DC isolators and connectors, usually due to poor installation or water ingress. A periodic inspection should check isolators, connectors, cable routes and roof penetrations, and a thermal image can spot overheating joints.
Last checked 24 September 2026 · 1 source
In more detail
- BRE (2018): 80 incidents investigated, ~0.01% of UK installations; 58 caused by PV, 16 involving PV but not caused by it, 6 unknown; 38 serious fires.
- Components implicated (probable+possible): DC isolators 30, DC connectors 12, inverters 9, DC cables 5, modules 5.
- Root causes (probable): poor installation 21, system design 6, faulty product 3, unknown 28.
- DC isolator failures: water ingress (e.g. upward-facing glands on exposed walls), under-rated isolators, AC-designed products used on DC, loose terminals.
- Connector arcing: mismatched brands of MC4-type connectors, poor crimps, moisture.
- Homeowner action: look (do not touch) for scorch marks, melted plastic, condensation inside isolator windows, cables rubbing on tiles; smell of burning = switch off at AC isolator/consumer unit and call an engineer.
The facts, dated
- 01BRE investigated 80 PV-related fire incidents (~0.01% of UK installations) — 80 incidents
market_data · UK · checked 24 September 2026 · GOV.UK
- 02DC isolators were the component most often implicated (26 probable + 2 possible cases) — 30 cases
market_data · UK · checked 24 September 2026 · GOV.UK
- 03Poor installation was the probable root cause in 21 incidents — 21 incidents
market_data · UK · checked 24 September 2026 · GOV.UK
What we saw in the field
Supports installer view that problems come from bodged installs rather than the technology itself.
Sources
Last checked: 24 September 2026