Johannesburg - As the rest of the country braces itself for stage 3 load shedding, the City of Joburg and City Power on Tuesday morning announced a pilot project called “load limiting” in an effort to eliminate future load shedding in the city.
In terms of the pilot, City Power would monitor household energy usage remotely and curb excessive consumption during periods of constrained supply to about 65 000 properties with smart meters.
It is the first project of its kind to be implemented in South Africa.
The need for this sort of management was underlined on Tuesday morning when Eskom issued a black power alert, begging customers to switch off.
A black alert is the most severe, and indicates “significant strain” on the electricity supply.
“Eskom will implement stage 2 load shedding from 6am, and this is likely to continue until 10pm,” said Eskom.
This morning load shedding was an earlier start to the cuts than usual, leaving commuters in certain areas stuck in rush-hour jams with some traffic lights out.
Eskom could not provide an update on the state of the system on Tuesday morning, but on Monday night reported it had a total generating capacity of 29 528MW, with more than 14 000MW offline due to planned maintenance and breakdowns.
Of this amount, 8 700MW was due to breakdowns.
Units off for planned maintenance still include Koeberg’s Unit 1, offline since February and due back only at the end of next month.
The loss due to breakdowns is the fifth highest reported this year; the worst day was January 26 with 10 515MW in breakdowns.
On Monday, Eskom implemented load shedding and load curtailment from 4pm to after 10pm.
It also load-shed on Sunday.
Last month City Power said it aimed to avoid the effects of Eskom’s load shedding by June, by managing Joburg’s consumption.
Tuesday morning’s announcement on load limiting is a key part of that.
Load limiting would allow City Power to accurately determine available supply in relation to consumption in real time and alert households that are above the required consumption threshold to cut down, said City Power managing director Sicelo Xulu.
When fully implemented, it would mean Joburg would be able to avert stage 1 and 2 and partial stage 3 load shedding.
It would save 153MW for City Power.
City Power plans to implement load limiting in two phases: first, on demand when Eskom issues a notification to municipalities to load-shed due to constrained supply, and second, advance scheduling to reduce consumption and pressure on the grid.
Households would be informed of the daily consumption rate and consumers would be expected to adhere to this threshold.
“Households that don’t comply will be remotely disconnected, thus sparing conforming customers from load shedding,” said Xulu.
During peak times, 7am to 10am and 4pm to 8pm during weekdays, consumers are encouraged to use only essential appliances. Energy-intensive appliances such as geysers, stoves and fuel pumps should be turned off during these times to avoid disconnection.
“We are continuously exploring how the power of technology can enhance security of supply.
“Load limiting is one of the ways in which City Power strives to ensure that we keep the lights on during periods of constrained supply,” he said.
Consumers will be educated on the new system before it is implemented.
City Power has begun implementing a ripple control system through which it can switch off geysers remotely when electricity is constrained to free up load and avert load shedding.
So far, it is enabling the utility to control 100MW of power.
The roll-out of solar water geysers around Joburg has saved another 60MW and the Kelvin power station has contributed an additional 150MW to capacity.
“Through a number of interventions, City Power has freed up additional power which has in turn been fed back to the grid,” said Xulu.
The Star