Nonfunctioning traffic lights, caused by power cuts, are a motorist’s nightmare and cause untold delays, hence the enthusiasm in Cape Town, where the first solar-powered traffic light in South Africa is now functioning.

The pilot site, an eight-robot intersection on Plantation road, Lotus River, has been fitted with a four-square-metre solar panel and battery packs to capture energy from the sun, and began opera-ting on October 1.

Solar panels at the top of the light pole are used to power the lights, and surplus power is stored in the battery packs, allowing the system to work throughout the night, and for up to three days of cloudy weather if need be. Solar-powered traffic-light systems have been operational in Europe for years and, more recently, have been manufactured in Japan.

The company implementing the project is MagCode SA, of Cape Town, and MD Reinhardt Hanel affirms that the company is confident that the project will succeed. “Solar technology is advancing very quickly, and there should be no reason why it will not soon be possible to run robots entirely on energy harvested from the sun,” he adds.

In addition to the solar panel, the intersection has been fitted with energy-efficient light-emitting diode (LED) heads, to increase efficiencies. “The change from halogen bulbs to LEDs reduced the energy consumption from 75 W a head, to about 10 W,” says MagCode SA director and engineer Stefan Hanel.

The company has built a mobile rig, with which it can demonstrate the benefits of the system to other municipalities and local administrations that might show an interest in the technology.

The solar-powered lights for the pilot project come at a cost of R150 000; however, if installed in larger numbers, the cost would decrease to R110 000 for a set of eight lights, for example.

The project is funded by Eskom, which is looking at various ways of alleviating pressure on the grid. “Besides the obvious benefits for motorists, being solar powered means the robots are more environment friendly, because they draw less electricity that has been generated by the predominantly fossil-fuel-burning power stations,” explains National Energy Efficiency Agency operations manager Barry Bredenkamp.

A standard eight-pole traffic light consumes about the same amount of electricity as a family of four occupying a three-bedroom house, and it is estimated that Cape Town’s traffic lights use the same amount of electricity as 1 200 homes. The objective of the solar-powered lights is to determine the extent to which traffic intersections can run without Eskom power, as well as to combat the inconvenience caused by power cuts, because the solar-powered traffic light will work even in the event of a power cut.

The results from the pilot site will be evaluated to determine how solar-powered traffic lights could most effectively be used throughout South Africa. It will provide an opportunity to address practical issues like theft prevention and ease of maintenance.

Besides electricity savings being monitored over the next three months, the pilot site will research and determine the savings for motorists on both fuel and time.