Eskom has implemented Stage two rational load shedding from 9am until 11pm.
This, the power utility said in a statement, comes as its electricity system has been severely constrained this week.
“As a result of the loss of additional generation, delays in the return to service of units that are on planned maintenance and limited diesel supply, it has become necessary to implement stage two rotational load shedding in order to protect the power system from a total collapse,” Eskom said in a statement issued on Wednesday.
Last month in a system status briefing, Eskom warned that in order to avoid load shedding, unplanned breakdowns needed to be contained at below 9 500MW. In the event generator breakdowns are experienced beyond 10 500MW, there will be high usage of emergency resources (diesel and pumped storage generators), which may lead to load shedding if the supply constraints is sustained for a long duration.
“The severe supply constraint being experienced has come about due to high levels of unplanned breakdowns that have exceeded the 10 500MW limit. The supply constraint is caused by, among others, five generating units that are unavailable due to boiler tube leaks.
“In addition, a conveyor belt supplying Medupi Power Station with coal failed on Saturday 12 October resulting in low volumes of coal being supplied to the power station thus limiting the generating capability to approximately half the station output,” Eskom said.
The power utility pumped storage and Open Cycle Gas Turbine (OCGT) generators have been used extensively since Saturday due to the shortage of generating capacity from coal fired generation. This has led to a decline in the dam levels and diesel tank levels.
Eskom has apologised for the negative impact of load shedding but assured to continue to work tirelessly to ensure security of energy supply.
Eskom has appealed to customers to continue to use electricity sparingly throughout the day:
• Set air-conditioners’ average temperature at 23ºC.
• Switch off your geysers over peak periods.
• Use the cold water tap rather than using the geyser every time.
• Set your swimming pool pump cycle to run twice a day, three hours at a time for optimal energy use.
• At the end of the day, turn off computers, copiers, printers and fax machines at the switch. Avoid stand-by or sleep mode.
Customers are advised to check their load shedding schedules on the Eskom or municipal website.
“We will keep customers informed if there are any further changes to the power system,” said Eskom.