The rapid uptake of solar PV and battery backup systems during South Africa’s loadshedding years solved an immediate problem, but it also introduced a quieter, less visible one.
A large number of systems were installed under pressure, often without the level of engineering oversight, compliance, and quality control required for long-term safety. Today, many of those installations are still in operation, and while they appear to be working, they may be carrying hidden risks.
One of the most concerning of these risks is the potential for fire.
It is easy to associate this risk purely with lithium batteries, but the reality is broader. Poorly designed or installed wiring, incorrectly sized cabling, overloaded PV combiner boxes, and inadequate fuse protection can all become sources of heat. Over time, these components can degrade or loosen, and when heat builds up in electrical systems, the conditions for ignition are created.
These risks rarely present themselves clearly in the early stages. Systems continue to operate, the lights stay on, and the monitoring app reflects generation. However, beneath that surface, small issues can develop into serious hazards if left unchecked.
Where the Risk Is Increasing
As an engineering-led business, AWPower has engaged with key industry players to better understand how these risks are evolving. Through collaboration with Santam and Fidelity SecureFire, as well as insights from ongoing system audits, it has become increasingly evident that solar- and lithium-related fire incidents are on the rise.
Ageing systems are of particular concern.
The PV combiner box is one component receiving increased attention. This device combines direct current (DC) electricity from multiple solar panel strings into the inverter(s). Although it plays a critical role in the PV system, it is often overlooked once installed.
Over time, combiner boxes can become overloaded and internal connections may deteriorate, creating a potential fire risk. In older designs, fuses may burn out under overload conditions, and with multiple fuses present, failures may go unnoticed unless system performance is regularly monitored. Such issues are typically identified via remote monitoring and then confirmed through physical inspection.
A typical burnt fuse-holder is shown in the image.
Lithium battery installations also present their own challenges. Many residential systems are installed in garages or enclosed spaces. Even a minor impact, such as a vehicle lightly bumping against a battery bank can unknowingly damage internal cells. In some cases, this damage may initiate a gradual rise in temperature over a period of time, typically two hours for most lithium types, eventually leading to combustion and the release of hazardous gases.
These are not always sudden events. In many cases, there is a window of time where intervention is possible, provided the issue is detected early enough.
The Importance of Early Detection
One of the key challenges in managing fire risk in solar systems is that warning signs are often not visible to the user. Temperature increases within batteries or electrical components can occur gradually and without triggering immediate system faults.
Without monitoring, these changes go unnoticed.
Recognising this, AWPower has embedded a more proactive approach to fire safety into its maintenance and support offering. Through SolarSupport 26, a technology-driven maintenance and support programme, a layer of continuous thermal monitoring has been introduced to identify potential risks before they escalate.
At the centre of this approach is HeatWatch, an early-warning system designed to detect abnormal temperature changes in lithium batteries, electrical switchgear, and PV combiner boxes. The HeatWatch device is about the size of a mobile phone, has a long-life battery and is relatively quick to install by being attached with a gum-strip directly on key components within the system.
Once installed, they connect to Fidelity SecureFire’s Sigfox network, which provides extensive national coverage across South Africa.
HeatWatch Remote Monitoring & Dashboard
SolarSupport 26 subscribers who opted for HeatWatch, and members of AWPower’s support team will have access to the HeatWatch monitoring dashboard. A typical example of the HeatWatch Dashboard is shown below:
Fidelity’s Sigfox, which is a network providing national SA coverage mostly focused in areas where there is economic activity and population, is very similar to the SA cellular network coverage. Sigfox SA coverage is shown in the map below:
HeatWatch continuously tracks temperature behaviour and is monitored 24/7 by Fidelity SecureFire. This allows for early alerts in the event of abnormal thermal activity, creating an opportunity to intervene before a situation develops into a fire.
As a general guideline, it is recommended that a HeatWatch device is installed on each lithium battery as well as on the PV combiner box, ensuring that the primary heat-generating components within the system are covered.
Additional Protection Measures
While early detection plays a critical role, it is only one part of a broader safety strategy.
As a first line of defence, the inclusion of a specialised gel-type fire extinguisher provides an additional layer of protection. These extinguishers are specifically designed to suppress lithium-related fires quickly and effectively, addressing a type of fire that conventional extinguishers are not always equipped to handle.
The Fireblock 9kg gel-type extinguisher, supplied as part of AWPower’s offering, can be serviced in Cape Town and other major centres through Fidelity SecureFire, ensuring that the equipment remains ready for use if required.
In the video below, see how the FireBlock gel-type fire extinguisher, as supplied by AWPower, kills lithium fires quickly and effectively compared to other types of extinguisher:
A Risk Worth Taking Seriously
Solar remains one of the most effective ways to manage rising electricity costs and improve energy resilience. However, as systems age and installations become more complex, safety can no longer be assumed.
A system can appear to be functioning normally while underlying risks develop over time. Without regular inspection, monitoring, and maintenance, these risks remain hidden until they become critical.
Taking a proactive approach to safety does not require major changes to an existing system, but it does require awareness, the right tools, and a willingness to reassess installations that may not have received the attention they need.
In many cases, the difference between a minor issue and a serious incident comes down to whether the warning signs were detected early enough.
*Interested? Get in touch with us: info@awpower.co.za