13 June 2012 – Campaigns encouraging consumers to switch off and unplug or face the consequences of load shedding this winter often overlook how much South Africa’s ageing and poorly maintained electricity supply network is contributing to power loss.
While the amount of energy lost to poor connections and power spikes on overhead cables and other transmission infrastructure is currently unknown, using infrared technology to identify and prevent electricity loss could contribute significantly to the amount of electricity available for consumption.
“We will never know how much is being lost, be able to locate major loss areas or learn how to prevent this loss until we subject all substations and switchgear to infrared inspection,” Wernher Le Hanie, a thermographer at Marsh Africa says.
Infrared thermography allows humans to visualise and understand what a thermal camera sees – with a spike in temperature indicating an abnormality in the flow of electricity. Le Hanie and his team have used infrared cameras to identify areas of resistance, and hence energy loss, on property circuits and overhead rail cables.
“While using thermographic surveys to investigate electricity loss for these commercial customers it became evident that municipal grids were also losing significant amounts of power from their network of faulty connections and points of resistance, even before any breakdowns occurred.”
Major cities, like Johannesburg, have by far the greatest concentration of cables, connection and transmission points, all areas of potential resistance and loss. And just because there is not a breakdown, doesn’t mean there isn’t loss.
“Our experience with infrared technology show us that cities, with their multiple opportunities for electrical resistance, are the most likely areas of power loss – often accounting for months and years of increased resistance and lost power before a breakdown occurs,” Le Hanie says. As such, even when a city’s electricity supply network appears to be operating smoothly vast amounts of power are being lost and wasted.
With infrared thermography cameras now in South Africa and currently in use in the electrical, mechanical, building, veterinary, medical, security and transport industries, “it is a pity that South Africa’s major cities are not applying this technology more effectively to their electricity supply grids.”
Moreover, those few municipalities that are using thermography to combat power loss and other breakdowns often use it incorrectly. For example, switchgear panels are often not equipped with infrared windows. Nor are they left open due to safety concerns. This results in thermographic scans only reflecting surface issues – missing weak connections and other faults deeper within the panel.
Compared with maintaining it, it always costs more to replace or rebuild equipment. The cost of shutdown for repairs should also be considered along with the cost of damage to the network. “If you include the cost of lost productivity and stock trade etc. the cumulative cost of South Africa’s ageing and poorly maintained municipal electricity grids to the overall economy become significant,” Le Hanie argues.
The worst case is when electrical equipment catches fire due to a loose connection resulting in the entire system burning down – even though this could have been avoided by preventative infrared scanning.
Beyond these spectacular and very visible consequences of a poorly maintained municipal electricity supply network, given that most of the power lost in South Africa is unseen and unmeasured, “there is a dire need to start applying modern predictive infrared risk assessment to our electricity grid, especially in our major cities.”