Solar panel fire safety and certification in the UK

A solar PV system is an electrical installation on your roof that produces voltage whenever it is light. Fires are rare, and when they do happen the cause is usually the installation rather than the panel. This guide explains where the risks are and what to check before you sign.

What the UK evidence shows

The most detailed UK study is BRE National Solar Centre’s investigation for the government into fires involving solar PV. Of 80 incidents investigated ¹:

• DC isolators were involved most often, followed by DC connectors and inverters; the panels themselves only rarely.
• About 36% of incidents caused by the PV system were attributed to poor installation, 10% to design errors and 5% to faulty products.
• Recurring faults included water getting into isolators through upward-facing cable glands, badly crimped connectors and loose terminals – all avoidable with good workmanship.

In other words, choosing the installer matters at least as much as choosing the panel.

MCS: the UK installation standard

In the UK, the Microgeneration Certification Scheme (MCS) sets the standard for domestic solar installations. You need an MCS-certified system and installer to get the Smart Export Guarantee ², and the MCS solar PV installation standard (MIS 3002) covers systems up to 50 kWp ³. Among its requirements ³:

• the roof structure must be checked by a competent person to make sure it can carry the load, including snow loads; for unusual roofs, shallow pitches or roofs showing distress, a structural engineer must be consulted;
• systems on or in pitched roofs must use mounting kits certified to MCS 012, which are tested for the roof environment;
• where panels form the roof covering (in-roof systems), the kit must have the right fire performance rating for its location;
• connectors must be assembled with the correct tools and procedures, and components must be approved to work together unless the manufacturer declares them universally compatible.

Panel certification: IEC 61215 and IEC 61730

Two points to remember:

• IEC 61215 is not a lifetime prediction – the IEC says so explicitly ⁴.
• Ask for the actual certificate, naming the test lab and the exact panel model, not just a logo in a brochure.

Our panel data comes from the Californian CEC list, which does not include IEC certificates, so we don’t show them per panel.

Wiring and electrical safety

The electrical installation must comply with the IET Wiring Regulations (BS 7671), which include a dedicated section for solar PV. Good practice you can ask about:

• one connector type throughout, matched to the panels’ own connectors;
• DC isolators installed so water can’t collect in them, and cables routed and clipped so they can’t chafe or sit in water;
• a clear shutdown procedure and labels at the consumer unit and meter so electricians and firefighters know there is a PV system.

Roof, fixings and weather

1. Structural check of the roof, in writing – especially on older roofs.
2. Wind loading appropriate to the site (height, exposure, edge zones, coastal locations).
3. Tiles and slates: roof hooks must not crack tiles; flat-roof penetrations must be watertight.
4. In-roof vs on-roof: in-roof systems replace the roof covering, so fire rating and weatherproofing matter even more.

Checklist for your installer

• Are you MCS-certified, and will I get the MCS certificate?
• Which connectors will you use – the same make and type as on the panels?
• Is the mounting kit MCS 012 certified?
• How will you check the roof structure, and can I have it in writing?
• Are the panels certified to IEC 61215 and IEC 61730? Please send the certificates.
• Where will the inverter and DC isolators go, and how is the system shut down safely?
• What workmanship guarantee do you give on roof leaks and fixings?

Have the system checked after storms, roof work, a burning smell or crackling sounds. Compare panels and inverters on measured values in our solar panel database and inverters.