The camera that saved Eskom billions

Checking the state of the insulator discs on power lines led to a new invention. (David Harrison, M&G)

Checking the state of the insulator discs on power lines led to a new invention. (David Harrison, M&G)

It all started with a phone call that got forwarded through to Roel Stolper by chance. It was 1992, and that conversation – between Stolper, a researcher at the Council for Scientific and Industrial Research (CSIR), and Eskom’s Wallace Vosloo – and their subsequent research collaboration has saved the power utility millions of rands and created a multimillion-rand business.

Vosloo had a problem: he was doing his doctorate in the use of different insulators on transmission lines – they sometimes look like a collection of stacked side plates or an upside-down bell which connect the power line to the pole or pylon – but he could not see the effects of the insulator, whether current was leaking out, or determine how it was ageing.

This is why he phoned the CSIR and got put through to Stolper. “I asked: ‘What do you need, describe it, and why do you need it?’” Stolper remembers.

The problem hinges on something called coronal discharge, an electrical leak from the power lines, which can be caused by faults in the line or a defective insulator.
But you cannot see this discharge, which is ultraviolet (UV) light, because it is outside the visible spectrum.

“Corona discharges are in the unseen spectrum of the eye, so you need a kind of transducer [a device that converts one form of energy into another; in this case, it acts like a detector] to make the invisible visible,” Stolper explains.

So the CSIR and Eskom, through these two researchers, created a camera that could detect UV radiation.

“The very first camera only worked at night,” Stolper says, “and it was used, but then we had a further brainstorm: How can we extend the operation time from night to day?” Enter the CoroCAM, a corona detection camera that is now sold in more than 50 countries in the world.

Far beyond the research
The applications of this little camera – which looks like an old-school camcorder – go far beyond Vosloo’s research project, especially because the researchers continued to tweak it, adding capabilities such as infrared detection (which is on the other side of the visible spectrum to UV).

Corona discharges can occur when there is a fault on a transmission line. If left unattended, this can cause the current to arc (which is when it discharges into the air) or the power line to break down completely. There are tens of thousands of kilometres of transmission line crisscrossing South Africa. “Typically a line dip is costed at approximately R150 000 per event, [depending] on the line location, type and fault,” Barry MacColl, general manager of Eskom’s research, test and development unit, told me in 2012.

“This does not take into consideration the loss of supply to the customer or the substation equipment that is affected.” Through the use of multispectral technology, or the CoroCAM daylight cameras, the inspector has three times as much information available, especially for internal defects.

Dirk Lindeque, who was first introduced to the project in 1999 as its business development manager at the CSIR, says that the importance of corona detection is that you can find faults at a very early stage.

“If there is a fault situation, the electric field at that point is higher than normal. At a certain point, it starts ionising the air [ionisation is the process by which an atom loses or gains an electron] and ozone is formed; nitric acid is released into the air as well,” he says.

This power is lost, effectively floating into the air and this loss increases if it is humid or rainy. Although the power loss is small, it affects the transmission line components around it.

“If [the power utilities] don’t know that there is a corona or a fault, they will leave the insulator and expect it to last fifty years … but because of the damage it might only last ten years,” Lindeque says. But with the CoroCAM maintenance operators can image the fault before it becomes a serious issue.

Pressure to commercialise
The problem for the CSIR’s CoroCAM team was that the technology became so popular. Lindeque says: “We suddenly found ourselves earning money as a business inside the research institution and there was a lot of pressure on me to commercialise [the product].”

This is why, in 2008, the technology was spun out into a standalone company, Uvirco, with Lindeque at the helm. Uvirco stands for Ultra-Violet, InfraRed Company. Stolper now holds the international patent to the technology.

The CoroCAM is present in more than 50 countries; in fact about 95% of Uvirco’s cameras are exported. The company – which has an annual turnover of about R40-million – has about 36 distributors.

Lindeque jokes that “we deal with them, they deal with their customers. That way we don’t need to learn Chinese, Russian, Japanese and French.”

The CoroCAM is assembled, tested and qualified in South Africa and Lindeque is quick to note that “all the manufacturing of mechanical parts, reworks and covers is all made in South Africa”, with more than fifty local suppliers.

Yet, the heart of the CoroCAM, the detector, is imported and counts for about 50% of the hardware costs. Lindeque says that they are planning to move the manufacture of the lens, currently made in Switzerland, to South Africa.

These cameras are well beyond the price of the person in the street. Your basic CoroCAM, with no bells and whistles showing only the visible and UV spectrum, will put you back €45 000. The handheld multispectral camera, which includes infrared, will cost you between €60 000 and €70 000.

But for the power utilities that use them, the capital expenditure is worth it. The alternative is spending millions, possibly billions, on fixing equipment that you expected to last for another 30 or 40 years.

  This is an extract from Sarah Wild’s book Innovation: Shaping South Africa Through Science, which will be published in September by the Gordon Institute of Business Science and PanMacmillan South Africa

Sarah Wild

Sarah Wild

Sarah Wild is a multiaward-winning science journalist. She studied physics, electronics and English literature at Rhodes University in an effort to make herself unemployable. It didn't work and she now writes about particle physics, cosmology and everything in between.In 2012, she published her first full-length non-fiction book Searching African Skies: The Square Kilometre Array and South Africa's Quest to Hear the Songs of the Stars, and in 2013 she was named the best science journalist in Africa by Siemens in their 2013 Pan-African Profiles Awards. Read more from Sarah Wild

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