In the past 18 months, there have been at least seven fires at City Power substations, costing the Johannesburg power utility an estimated R106-million. The Brixton substation was the latest casualty and came less than a week after a fire at a City Power substation in Soweto.

Read in Daily Maverick: Brixton substation fire compounds Joburg electricity and water outage woes

The substation fires have caused significant inconvenience for Johannesburg residents and have compounded the challenges of load shedding.

Fixing substations can take time and, according to City Power, the asset renewal backlog on substations and transmission lines is R3.6-billion.

The substation fires are caused by a range of issues including theft and vandalism, rolling blackouts and overloading the transformers.

Daily Maverick asked City Power if it had any contingency plans to deal with substation fires. 

City Power’s spokesperson, Isaac Mangena, said: “City Power is operating in a strongly regularised environment and as such we are forced to have contingency measures. We have contingency plans for all the substations as required by the code of practice mandate and authority from Nersa [the energy regulator] as part of the Electricity Regulation Act.”

He said City Power had updated its planning and design philosophy to include the following:

• Construction of firewalls. This is part of a risk reduction strategy to reduce the likelihood of a faulty or burning transformer affecting healthy plants.
• Establishment of interconnectors between substations. This includes the provision of an alternative source of supply from a different substation to provide additional capacity in the case of a total blackout in a substation. This option depends on the availability of a similar primary substation in the vicinity.
• Upgrade of substations. Asset renewal programmes to refurbish and upgrade equipment at substations. This includes the installation of fire suppression systems to limit or reduce the impact of fire.

Mangena said City Power had gone on a drive to accelerate predictive and preventative maintenance to improve infrastructure conditions and prevent the likelihood of failures while reducing the number of plants out of service. 

Energy expert Chris Yelland believes the main cause of the problem is transformers which are not well maintained and managed.

“In South Africa, in many municipalities, even Eskom, the levels of failures of transformers are too high and it’s just a lack of attention to detail. In a substation environment, there should be comprehensive, protective devices that protect, in particular, transformers from any damage caused by overloading or any other reason, because in reality they can be overloaded,” he said.

“You have to have a whole maintenance strategy for transformers. A lot of the problems are caused by old, ageing transformers that have reached the end of life and are not being replaced. The other reason is that transformers are poorly maintained,” he said.

Not all of City Power’s substations are fully operational following the fires and the estimated cost to fully restore the affected substations is R106-million.

Below is a breakdown from City Power of the current status of the affected substations and what it would cost to restore them to full capacity:

• JG Strydom switching station is operating with ring main units. The estimated cost of full restoration is R18-million.
• Robertville substation is operating with one transformer. The estimated cost to fully reinstate the high voltage bay is R15-million.
• Eldorado Park substation is operating with two transformers and two feeder boards. The estimated cost of full restoration is R34-million.
• Lenasia South substation is operating with one transformer. The estimated cost of full restoration is R15-million.
• Lotus substation is running with one transformer. The estimated cost of full restoration is R6-million.
• Soweto Local substation is in the progress of being restored using a strategic spare feeder board. The estimated cost of full restoration is R15-million.

Brixton is a traction substation. The estimated cost of full restoration is R3-million. DM