Evolving risks of PV Solar Systems to be addressed at upcoming Liability Conference

Photovoltaic (PV) solar systems are becoming more popular than ever as we strive to convert sunlight into electricity to reduce our greenhouse gas emissions. But these systems also carry an emerging risk.

That’s according to Mark Cousins, a partner at Burgoynes, who specialises in investigating fires, explosions and other major incidents.

Australia has the highest uptake of solar PV systems globally, with around 3.4 million rooftop installations in use, according to the Clean Energy Regulator.

Identifying the cause

Cousins, who will address the ANZIIF Australian Liability Conference in Sydney in October, says as more PV solar systems are installed, reports of fires attributable to them are becoming more frequent. 

He notes that where the fire is the result of the solar system, poor installation accounts for most of the incidents.

To put the issue into context, of the 3,000 fires investigated by Burgoynes each year, only around 10 to 15 actually involve PV solar systems. 

And, when properly investigated, not all these cases are the result of the failure of the solar system involved – that is, the solar system is often a casualty rather than the cause of the incident.

Cousins explains that a solar system essentially consists of an array of PV panels that convert solar radiation (sunlight) into direct current (DC) electricity, and an inverter that converts the DC electricity into alternating current (AC) electricity at the correct frequency.

The AC output from the inverter is connected to the consumer unit or distribution panel, and the power from the system supplies the circuits connected to that consumer unit or distribution panel, providing power to the premises. 

This arrangement means that any excess power generated by the system that is not used by the premises is fed directly into the electricity supply grid.

The inverters are the most complex part of any PV system, but Cousins says investigations tend to show that only a minority of the fires involving defects of such systems were the result of a defect in the inverter itself.

In contrast, many more of the fires are a result of defects in ancillary equipment – which includes cable connections and isolators – and the majority of those are a consequence of poor installation.

Emerging risks in electrical systems

That being said, Cousins says solar panels are much like other electrical appliances.

“Ultimately, most electrical systems are fine and don’t have any issues. A small percentage of electrical items and appliances fail, but generally, when they fail, they just stop working.”

Provided that electrical systems, which include solar systems, are installed by somebody reputable, the risks of failure should be reasonably small.

While most failures are benign, Cousins adds that there is a risk that solar and other electrical systems will break down in a catastrophic manner that leads to a fire.

Another possible emerging risk, according to Cousins, could be fire issues with electric cars and battery storage systems, both of which employ lithium cells or batteries.  

“The actual number of electric cars and storage systems with such batteries is increasing,” he says.

“The lithium-based technologies are still maturing. Also, the overall effects of cell or battery age in real-life situations are still emerging. For example, do we know what's going to happen as more of them reach the end of their life? Essentially, we don't, as there isn’t enough data on this yet.

“With age, all things will eventually fail. Solar system equipment and batteries in cars are no different. As they age, there will likely be an increased risk of a small percentage failing, but we don’t yet know just how many units this will involve or how large the risk will be.

“There is a risk that electric vehicles will catch fire, but then again, fossil fuel cars regularly catch fire too.” 

Similarly, Cousins says the infrastructure we connect the solar systems to, which will also be used to charge electric cars, such as the switchboard in a domestic property, may be many years old and may not have been inspected or serviced for many years. 

“This will also present an increased risk of safety failure on the fixed electrical distribution equipment.”

Charting a career in fire investigation

Cousins began his career in the Royal Navy dockyard in Plymouth, as an electrical fitter with the Ministry of Defence in the United Kingdom.

He then completed an electrical engineering degree and became a chartered engineer before moving into the field of fire and forensic engineering investigation.

He joined Burgoynes’ Cardiff office in 2002, becoming a partner in 2014. Moving on to attain Certified Fire Investigator status with the International Association of Arson Investigators in 2018 and in 2019, he opened Burgoynes’ Melbourne office.

He suggests fire and forensic investigation requires a broad skill set.

“When you receive a call to attend a fire or similar incident, you never quite know what you are going to arrive to and what you may find,” he says.

“It could be a fire that's caused by a pan of oil on the hob one day, a fire at a multi-million dollar factory the next day, or even a fire onboard a ship, possibly one involving many thousands of shipping containers with varied contents.  

“While the overall investigation process for all such incidents is similar, each has its own distinct facets, and each will take on its own overall form. It is this that makes what I do such an interesting and varied profession, albeit sometimes a very smelly one!"

Find out more about the Australian Liability Conference