Featured: REG installs dissipated power absorber for energy efficiency

The Rwanda Energy Group (REG) has installed equipment intended to absorb reactive power, a move that will help increase efficiency and stability of power system, and avert damages that might be caused by excess voltage. The shunt reactor – an absorber of reactive power –, was installed at Birembo Substation in Kinyinya Sector of Gasabo District, on Saturday. Shunt reactors are installed to offset the capacitive effect of transmission lines and therefore improve the voltage profiles of transmission lines. In addition, they also help regulate the volt/VAR of power systems Reactive power is the imaginary power or apparent power, which does not accomplish any real work but merely moves back and forth in the power system lines. It is different from real power or active power in that, the latter is the true power given to any load, accomplishing useful functions such as lighting light bulbs, starting television and refrigerators among other equipment. The installed reactor in Birembo substation has capacity of 7.5 megavar, which will absorbed the reactive power from transmission lines across the country. A megavar is a unit of reactive power measurement equivalent to a million volt-amper. Gerard NDAYIZEYE, Chief Engineer in charge of electrical network protection at REG said that the parameters of power system change depending on the size of the load, entities who consume energy, or energy demand. He said that i that some energy if the reactive power goes high, the voltage profile goes higher than the nominal values that is recommended by the standards. For instance, he said the voltage that is received at Birembo substation is 110 kilovolts, but, it goes up to 120 kilovolts as it even gets the power generated from Kivu Watt power project and many more power plants located in western Province of Rwanda. “For example When the voltage goes higher up to 120 kilovolts, it makes the client undergo excess voltage which maybe out of nominal voltage,” he said. In a bid to address the problem to ensure that the client gets energy that meets standards, he said, they have installed the shunt reactor so that it makes compensation of the voltage so as to keep pace with standard power measurements, for power plants that generate power to make compensations for the parameters to return to normal values. “If there should be 200 volts in the client’s plug/socket, yet it is supplied with 230 volts± 10% , their light or radio can be damaged while they are rated 230 volts. So, we have to prevent such losses in advance,” he said. “We expect it to help us supply more stable power to the client,” he said pointing out that “for us to have stability and reliability of the network, we have to install reactive power compensators including shunt reactor.” Birembo Substation supplies power to various areas in Kigali including the Kigali Special Economic Zone – which hosts most of factories operating in Kigali – Kimironko, Kibagabaga Hospital, and Parliament. Power losses in Rwanda stand at 22 percent and are incurred in the distribution process, which is higher than tolerable loss of between 10 and 15 per cent in developing countries, according to Rwanda Energy Group. Rwanda Energy Group says that the country targets to enable 100 per cent of Rwandan households to access electricity by 2024. Currently, over 44 per cent of Rwandan households have access to electricity, indicate figures from REG.

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Featured: REG installs dissipated power absorber for energy efficiency