With recent reports of a domestic solar panel exploding on a roof at a West London council house, is there a hidden danger lurking? How does this impact confidence and the growth of solar photovoltaic (PV) panels across both domestic and commercial sectors?

Richard Williams is foremost an engineer, as well as founder and managing director of Aztec Solar Energy Ltd, with over 30 years in the energy services sector. Here he shares his views on safety issues facing the sector.

Last year, primarily due to the energy price crisis and a sustainability drive, the solar power industry saw a significant jump in solar PV installations. According to data from the Microgeneration Certification Scheme (MCS) – the standards organisation for solar energy and heating – 130,596 solar panels were mounted on UK roof tops in 2022.

This figure represented growth in one year which was previously only experienced in the three years between 2019 to 2021 combined, with the exception of those years following subsidy changes. These figures include all solar PV systems with a generating capacity of up to 50 kilowatts and registered with the MCS, notably therefore the figure is likely to be even higher, with an increasing number of installations in the UK not registered at all.

It does mean there are over 1.3 million registered solar power installations across the country, two thirds on the ground and the remainder on residential and commercial roofs, generating at least 15GW of solar power in the UK.

PV solar panels promise cost savings in terms of energy bills and are described as the clean and green electric energy. Seen in many a field and roof top, the growth of the solar PV panel has been significant and is changing the energy landscape.

But what controls are in place and who is monitoring safety?

Some may be shocked that PV installers are not legally bound to follow the guidelines or obtain accreditations from certifying organisations such as the MCS.

The big issue is that anyone can install a solar panel in the UK. Yes, work must be cleared by the local council and the government ‘recommends’ use of a registered electrician, but it’s not a necessity by law.

As with all electrical installations, electrical incidents may happen, which is why all electricians are qualified and must undertake regular competency training and on-going refresher training. Arc faults and faulty wiring can cause solar panels to catch fire and the risk of a solar panel catching fire is very low, but it is not zero.

Solar panel fires can be caused by improper installation or maintenance, and by damage from extreme weather events, such as hail or lightning. Higher voltages can be prone to arcing and is a known common cause of fires, but through the installation of micro inverters connected to the panel to convert the output to a safer level they considerably reduce the risks. As does using reputable and registered PV installers and, like maintaining your car, checks need to be done on all PV installations regularly. PV panels are often forgotten about and left to deteriorate and with those systems come risks, as with any neglected equipment.

It’s important to be up to date with the latest safety recommendations and regulations, and as with all things new, products evolve. Technologies continue to develop and with that have come new solar panels that are more resilient and offer an even greater reduction in fire risks. Understanding these products and their installation comes from experience and working in an evolving sector and with experts who can recommend the most appropriate panels and systems for installation.

The first step would simply be to ensure those installing your PV system and / or battery storage are registered with the MCS and has been installed in accordance with IET guidance.  This will verify the competence of the installer and the installer is duty bound to use verified products, so ensuring safety and quality.

Anyone concerned about their PV systems should seek further advice and consider retrofitting a micro inverter AC system or module level optimisation.  Look at the maintenance programme and ensure the system has been checked through periodic testing and by a professional. If at all worried and you suspect signs of overheating, isolate the supply, and call the installer.

As with all technologies that have been installed effectively and are maintained and managed, be assured solar PV panels will deliver clean, cost-effective power safely.

Aztec Solar Energy Ltd