Whether it is a blown light bulb from a sudden power surge or a television that flickers from low voltage, it indicates an unsteady flow of energy which, if regulated, could mean massive power savings for South Africa.
Voltage Power Optimisation (VPO) is a Japanese technology that can account for energy savings of up to 19%. It was patented in Japan 15 years ago when scientists figured out how to regulate electrical power and voltage in a safe, efficient and reliable way.
Power Optimisa holds the exclusive licence to distribute this technology in South Africa. Alan Palmer, Power Optimisa’s chief executive, said the device gives customers efficient control over the electricity they receive. “Electricity supply is variable, like water pressure,” he said. “It can go up and down, and voltages and currents vary.”
But VPO manages this through a solid-state electrical device. A controller in the device monitors the power and voltages within a series of custom preset intervals (known as “taps”) and adjusts it as required. Japan was motivated to implement the technology, Palmer said, because it had energy constraint issues for a long time and needed to import most of its power. More than 300?000 units have been installed since the 1990s.
The United Kingdom was the first to licence the technology from Japan and since then EDF Energy, one of Britain’s largest home and business energy suppliers, has given it a major endorsement and supplies it to clients. Large groups such as Tesco and Hilton Hotels have installed the devices.
South Africa was the second country to acquire a licence. The typical energy saving is 10% to 12%, although it is claimed that some VPO clients in South Africa have saved more. The device ranges in size from 50kVA to 2mVA and the cost is about R100?000 to R1-million. The payback period is between two and three years and the device is guaranteed for 10 years, although it is designed to last maintenance free for 35 to 50 years.
Power Optimisa clients include Pick n Pay, Woolworths, Gold Fields, Mr Price and McDonald’s. Eskom told the Mail & Guardian that VPO had a very specific application and when used in some locations it was possible to achieve savings. “However, the technology is known to be expensive and we would need to understand exactly what these savings would cost. A project proposal would need to be submitted to establish a benchmark for implementation of the technology.”
Eskom said it has asked the supplier several times to register as an energy services company (Esco) to enable it to use the Esco process to fund the project, but “the supplier has not as yet provided us with a test unit, which we would need to provide us with more technical information to support the technology”.
Graham Pateras, managing director of the Pick n Pay Family Store chain in Durbanville, in Cape Town, installed VPO in his shop more than three years ago and has had no difficulties since. “We were looking for a technology to help us save electricity, especially considering what is happening with Eskom. Some supermarkets electricity costs are higher than the rent,” Pateras said.
Power Optimisa first did an analysis to see what sort of saving was viable. “It is not possible on every site,” said Pateras, who is also a qualified electrical engineer. “Those closer to the point of distribution tend to have a higher voltage,” he said.
The University of Stellenbosch independently monitored VPO in Durbanville and found a saving of up to 9%. Eskom asked the University of Cape Town to do the same and found the result was similar.
Pateras said that the Durbanville Pick n Pay had expanded 30% in physical area but was using the same input power it had always used. Now that the expansion had stopped and the readings were more stable, Pateras said the year-on-year savings were 10% to 12%.
Chris van Heeswijk, Gold Fields South Africa’s senior consultant in electrical engineering, said VPO was installed at the Constantia office park which was the head office of Gold Fields’ South African operations until the end of last year. “The analysis indicated that we would save 10% on the Constantia office and experience showed that we saved between 7.5% to 9%,” he said.