Flames at Vodacom: The fire risks that come with solar panels

Vodacom’s Cape Town headquarters caught flames on Sunday, with solar roof panels being the suspected source – but could they really be?

Research by Stellenbosch University’s Fire Engineering Research Unit indicates that photovoltaic (PV) solar panels could be a fire hazard, if correct installation processes are not followed.

Despite few previously reported incidents in South Africa, the associated risk could soon increase as households and businesses switch to solar energy to cope with load shedding.

Stellenbosch University’s Prof. Richard Walls, a fire expert, says the leading cause of ignition is poor installation and a lack of maintenance.

Concerned about rushed installations amidst the growing preference for solar power, Walls strongly recommends appointing competent contractors to install and regularly maintain PV systems.

He says although there are some reputable installers, some lack sufficient expertise and training, often cutting corners and endangering lives.

What causes solar PV fires?

Aside from poor quality material and subpar installation, Walls says multiple factors can lead to ignition, just like with normal electricity.

• Ground faults;
• Hotspot effect – localised hot areas on the panels;
• Overheating of components;
• Arc faults;
• Build-up of combustible debris, like leaves – where the source of ignition is external.

What are the chances?

What’s the likelihood of solar panels igniting? Walls says there isn’t enough data to gauge the probability since the use of solar power is relatively new to the country.

“Due to the rapid rate at which this technology has been developed and applied, more research needs to be conducted to fully quantify the risk presented by these systems,” says Walls.

“So proper guidelines can be set up,” he adds.

Mitigation and prevention

Property owners with solar PV panels can implement a number of measures to prevent and mitigate fires.

Using trusted contractors

It’s strongly advisable to enlist the services of licensed contractors with sufficient experience to install and maintain your solar PV system.

Make sure to get enough information about potential installers before choosing one, to avoid risks posed by poorly installed panels.

Module-level power electronics (MPLEs)

According to research by the Fire Engineering Research Unit at Stellenbosch University, using MPLEs like micro-inverters or DC power optimisers can mitigate solar panel fires.

The research suggests MPLEs provide the system with a module-level rapid shutdown function, which can disconnect panels and prevent further generation of electricity in the event of a fire. MPLEs can also detect panel malfunction, which can be quickly corrected to prevent possible ignition.

Strategic placement of PV panels

Walls warns against placing panels too close together. 

“Sufficient and wide [space] should be provided for proper maintenance and cleaning”, says Walls.

In the event of fire, closely placed panels can hinder firefighters’ access to the roof’s apex.

Walls also says attempting to walk on solar panels can pose danger due to possibility of fire travelling between panels.

Mechatronic engineer and Stellenbosch University lecturer, Courtney Devine says “PV panels continue to produce power, even when disconnected”.

“Which is a significant risk to firefighters,” she adds.

Walls indicates that clustering panels can prevent ventilation by trapping smoke and stopping fire from escaping.  

“There should be a gap between panels to allow flames and smoke to escape.”

The fire expert also warns that fires are likely to spread faster when panels are too close – travelling from one panel to the next.

“The gaps… can interrupt a spreading fire and limit the damage it inflicts on the roof, if applied strategically,” he says.

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