New load shedding stages for South Africa about to take a step closer to reality
Friday (22 September) marks the last day that South Africans and other stakeholders can submit comments on the new proposed load shedding stages for the country.
The national energy regulator Nersa published the consultation document on the restructuring of load shedding on 11 August.
Once the comment window has closed, responses will be collated and taken into consideration for the final decision on the proposals. Once finalised, the new rules will ultimately be known as the NRS 048-9 Code of Practice Edition 3.
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.
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.
New load shedding stages
The key change in the document comes in extending load shedding stages to stage 16 – but the structure of the new stages may be unfamiliar to what most South Africans have become accustomed to.
At present, most South Africans understand each stage of load shedding to reflect 1,000MW of power that is removed from the grid.
However, under the proposed structure, this is rather expressed as the percentage of demand assumed by the System Operator at the time the stage is called. The percentages range from 5% of demand at stage 1 to 80% at stage 16.
While these percentages are in-line with the current Code of Practice, the percentages in the code being used now refer to a percentage “reduction in load profile of the national non-curtailment load” – not specifically demand.
The consultation paper also makes no mention of specific ranges (ie, +/- 1,000MW) as is the case in the standing code – although this may change in the final document.
“The specific reduction in load required to stabilize the system under a national supply constraint will be dictated by the power system conditions that prevail at the time,” Nersa said.
The proposed schedules also include the structure for customers who are part of the load curtailment programme.
The proposed stages are as follows:
Stage | Reduction required through load shedding | Reduction required through curtailment |
1 | All stage 1 load scheduled by utilities 5% of demand | 10% reduction in normal demand profile |
2 | All stage 2 load scheduled by utilities 10% of demand | 10% reduction in normal demand profile |
3 | All stage 3 load scheduled by utilities 15% of demand | 15% reduction in normal demand profile |
4 | All stage 4 load scheduled by utilities 20% of demand | 20% reduction in normal demand profile |
5 | All stage 5 load scheduled by utilities 25% of demand | 30% reduction in normal demand profile |
6 | All stage 6 load scheduled by utilities 30% of demand | 30% reduction in normal demand profile |
7 | All stage 7 load scheduled by utilities 35% of demand | 40% reduction in normal demand profile |
8 | All stage 8 load scheduled by utilities 40% of demand | 40% reduction in normal demand profile |
9 | All stage 9 load scheduled by utilities 45% of demand | 50% reduction in normal demand profile |
10 | All stage 10 load scheduled by utilities 50% of demand | 50% reduction in normal demand profile |
11 | All stage 11 load scheduled by utilities 55% of demand | Reduction to essential loads or as instructed by SO |
12 | All stage 12 load scheduled by utilities 60% of demand | Reduction to essential loads or as instructed by SO |
13 | All stage 13 load scheduled by utilities 65% of demand | Reduction to essential loads or as instructed by SO |
14 | All stage 14 load scheduled by utilities 70% of demand | Reduction to essential loads or as instructed by SO |
15 | All stage 15 load scheduled by utilities 75% of demand | Reduction to essential loads or as instructed by SO |
16 | All stage 16 load scheduled by utilities 80% of demand | Reduction to essential loads or as instructed by SO |
According to the document, the responsibility for keeping the national electricity grid stable lies with the National Control Centre (NCC).
“If the NCC requires additional load reduction, utilities may assume this is in the best interest of the grid. The System Operator will undertake to understand, via network studies, the impact and management of the grid under lightly loaded conditions caused by high – above stage 8 – stages of load shedding,” it said.
The full consultation paper can be found here, or embedded below.
Last-minute written comments can be sent to [email protected] or hand-delivered to Kulawula House, 526 Madiba Street, Arcadia, Pretoria, 0083; or posted to PO Box 40343, Arcadia, 0007, Pretoria, South Africa.
Read: Why Tuesday is the worst day for load shedding in South Africa