The Power Alert system, launched on May 22, has taken only three weeks to prove its value, Eskom said on Thursday.
The power utility said it expected a turbulent weekend in the Cape after the shutdown of the Koeberg nuclear power station’s unit one on Friday afternoon.
With both Koeberg units unavailable, the city faced an additional shortage of at least 400MW in the early morning (6.30am to 10am) and early evening (5.30pm to 9pm) peak demand periods.
But coupled with the technical good fortune was the response from the Cape Town consumers to the Power Alert messages, said Eskom spokesperson Fani Zulu.
”We do not yet have the exact numbers, but certainly on Friday night, consumers’ responses resulted in significantly less load-shedding than what we expected.”
Eskom’s good fortune included Koeberg returning to service almost 24 hours earlier than planned, which meant that on Sunday no load-shedding was necessary. On Friday and Saturday the pumped-storage schemes had enough water to provide emergency power supply.
Eskom also received permission from the National Nuclear Regulator to use the gas turbines at Acacia for emergency generation.
Power Alert was intended for broadcasting on weekdays only, but the latest crisis required a weekend broadcast as well.
”And although load-shedding could not be avoided, the residents of the Mother City joined forces and came to the party in a big way, proving that a concerted effort does make a remarkable difference,” Eskom added.
Although Koeberg’s unit one is generating electricity at full capacity again, unit two is still on its refuelling and maintenance outage.
Therefore, residents of Cape Town are reminded of the Power Alert colour-coding and the actions required for each colour:
Green — there is limited strain on the electricity supply of the Western Cape. Consumers still need to use electricity wisely by, for instance, switching off lights in unoccupied rooms.
Orange — the electricity supply system is under some strain, and residential consumers are prompted to switch off non-essential loads such as tumble dryers, washing machines, dishwashers, pool pumps and any unnecessary lights for the duration of the evening peak period or until notification of a green status is given. The shedding of these loads is not expected to cause any discomfort to residential consumers.
Red — the electricity network is under increasing strain, and possible supply interruptions are imminent. Residential consumers are further prompted to switch off additional loads such as stoves, microwaves, kettles, space heating, air-conditioning and any unnecessary lights. This should continue for the duration of the evening peak period or until notification of a green or orange status is given.
Brown — the electricity supply system is under significant strain and load-shedding is in progress. Residential consumers are prompted to switch off all loads not absolutely essential except the minimum lighting required for the room they are in and their television set (which they need to receive further information). This should continue for the duration of the evening peak period or until notification of a change in status is given.
Eskom also requested consumers in the Western Cape continue to switch off their geysers when arriving home after work and only to switch the geyser back on when going to bed, thereby helping alleviate the continued strain on the electricity supply system. — Sapa