Kathy Gibson reports – Rooftop solar has become the most in-demand solution for South African households and businesses – but there are many challenges in installing and maintaining these systems, which require a high level of skill to counter.
Prinaven Naidoo, solar channel manager at Huawei Digital Power, points to recent news reports about rooftop solar fires, and accidents involving lithium ion batteries.
Solar fires have hit business, warehouses, homes and retailers around the world, with most of them caused by over-voltage. “So fires are a bit problem for solar photo voltaic (PV) systems,” Naidoo says.
A massive 70% of all the faults in a solar system happen on the DC side – this is where the power is produced. The current is fed into the inverter, which converts it to usable AC.
Faults that could result in a fire include unreliable soldered joints within modules, broken PV cables or loose PV connectors.
A solar PV fire burns at 3 000 degrees, so it causes immense damage, Naidoo says. “And an electrical fire will continue to burn until something stops it by breaking the circuit.
Naidoo advises that rapid shutdown is a standard that is starting to be built into fire safety standards.
A major challenge when fires occur is that firemen are unable to extinguish them because they continue to burn. And, because there is still voltage running through the system, adding water raises the danger of electrocution.
“Rapid shutdown optimisers can help the system to produce more power, and also quickly cut off the power in the PV modules if a fire breaks out,” Naidoo explains.
“These are important for fire safety,” he adds. “And insurance companies are going to start demanding them.”
He urges companies and individuals to insist on these devices to protect themselves from total loss caused by an uncontrollable PV fire.
Countries around the world are starting to set standards for rapid shutdown. “The standards are coming in South Africa,” Naidoo says. “Everyone who has solar systems today will be non-compliant, and will have to go back and upgrade.”