Staff Writer3 March 2023
The National Rationalised Specifications (NRS) Association of South Africa says that it is currently drafting new load shedding stages for the country, planning for any likelihood that Eskom is forced to move beyond stage 8.
The NRS is a voluntary forum of organisations that was formed to collaborate and develop voluntary industry specifications to standardise equipment specifications across the South African Electricity Supply Industry.
The group is a key body involved with developing and compiling the NRS 048-9 Code of Practice – the code or regulation that essentially governs load shedding.
The NRS 048-9 Code of Practice is primarily an electricity utility-driven and executed document that derives its mandate and authority, once approved by the National Energy Regulator of South Africa (Nersa), as part of the Electricity Regulations Act.
The association confirmed it is currently working with Nersa to develop and approve NRS 048-9, Edition 3.
When the first edition of the NRS048-9 code was established in 2010, load shedding stages were capped at Stage 4 – representing 25% of the base load – requiring utilities to “find” electricity load under emergency conditions.
According to the NRS, ‘finding’ electricity with 75% of the load not being used was reasonably straightforward. However, attempting to do so beyond Stage 4 was not easy.
The need for Stage 6 load shedding in 2019 prompted the NRS 048-9 Work Group to consider extending the load shedding stages to manage load shedding to Stage 8 (Edition 2).
In Stage 8 half the electricity load is shed, and the other half is waiting to be shed, it said. Under these conditions, it is generally much harder to “find” electricity load, it said.
Given the deterioration of Eskom’s grid and energy availability, it has now become prudent to plan even further ahead.
The group said the final NRS 048-9 Edition 3 will now provide a methodology for utilities to reduce the whole load base in a structured way. Ostensibly, this would provide for 16 stages of load shedding – although the final picture could look very different with other changes under consideration.
This also means that contingency plans for the unknown – ie, “what happens beyond stage 8” – can be dropped.
“Once all the load is used, there is no need for a contingency option,” it said.
The NRS stressed that just because the new load shedding schedules will extend beyond stage 8, it does not necessarily mean that the country will move beyond stage 8 – it’s just planning ahead.
“The public is assured that the need to plan for load shedding beyond Stage 8, and the removal of the associated contingency measures, is primarily a proactive measure to enable the various electricity utilities, especially Eskom, to be in a state of readiness and preparedness to respond in the event of and the need to – but hopefully not – institute load shedding beyond Stage 8 levels.
“Although the Association believes that NCC and SO have managed load shedding well, often under difficult circumstances, to keep as many of the lights on as possible, it feels that the proactive planning and preparation for load shedding at elevated stages will prevent errors from occurring,” it said.
What is being proposed
On top of adjusting the load shedding stages, the NRS is also considering changing the way load shedding is handled – including the blocks (times) that outages occur.
Other changes under consideration include:
- The removal of non-16 block or non-2-hour options
- The removal of contingency sections
- Explicit instructions for utilities to keep lists of their exempted loads
- Allowing municipalities to use the gap between 5% and 6.25% for critical electricity loads that benefit all customers, while allowing Nersa to audit and possibly undo this if inequity is discovered
- More specific instructions on how load shedding is done to help the System Operator protect the system and frequency
- Specifying that single blocks must be shed and returned in turn
- Allowing the System Operator to dictate changes to odd or even hour shedding to balance the load
- Allowing the National Control Centre to intervene in the real-time shedding of utilities to improve frequency control
The processes to change the load shedding stages and schedules are still underway.
Once the association’s management committee has approved the NRS 048-9, Edition 3, the Code of Practice document will be forwarded to Nersa for approval once it has satisfied all Nersa’s internal processes and public consultation.