General Comment

The only way that eThekwini Electricity can contribute to the national requirement for a rapid reduction of load when Eskom’s generation capacity is about to be exceeded is to use the remote control facilities at our central Control Centre to switch out transformers and/or feeder circuits at major substations. Owing to the reaction time required, it is impractical to send staff into the field to switch the hundreds of circuit breakers in, given that the switching for each block has to be reversed 2 hours later.

It has therefore not possible to cater for the needs of individual customers or groups of customers.

Question 1.     Why aren’t we given advanced notice for Load-shedding?
Load-shedding is the last resort in a number of steps taken to prevent a total grid collapse and a national blackout. Hence, it is an emergency response to an emergency, where all other measures have failed and this only becomes evident shortly before emergency load-shedding is declared.
It is also not unusual that an emergency is declared and a reduced demand is seen on the network and load-shedding is averted at the last minute.

Question 2.    Why am I affected when I know of other areas which have not experienced load shedding?
This will be for one of two reasons. The areas not affected are on the same transformer or circuit, which supplies a critical load that would have a serious regional impact if isolated. The other reason would be that the particular circuit cannot be remotely opened when it was supposed to be switched off.

Question 3.    Why am I scheduled to be switched off only in the evening or morning hours?
Our approximately 730 000 customers have very diverse needs and whilst we have endeavoured to keep the schedule as simple as possible for better understanding, we needed to balance them against a host of other criteria. 

Without getting into the technical detail, the result is that we could not avoid some customers getting scheduled for predominantly morning hours whilst others were scheduled for predominantly evening hours.

Load-shedding is ONLY implemented under an extreme emergency and sustained load-shedding over sequential days is unlikely, hence customers that are switched off will only experience a single or at the worst case a few incidences of load-shedding a year.

Question 4.    Why am I scheduled to be switched off at the same time every alternative day?
The largest number of complaints from customers during the initial load-shedding of 2008 was that they did not know when they were scheduled to be switched off. It was therefore deemed practical to only have 2 different switch-off times per Block on alternative days for Stages 1 & 2. This made it easier for customers to remember or even write down.

Question 5.    How do I know which Block I am in?
The attached Schedule is a guideline to determine which Block a customer is in and should be accurate under normal operating conditions. However, each customer can be fed from multiple substations, some of which could be in different Blocks. Under fault or high load conditions, customers can be fed from alternative neighbouring substations, some of which may be in other Blocks. It is extremely difficult to report on this dynamic change in network configuration in real time and we appeal to customers to be patient if this situation does occur.

It is recommended that if load shedding occurs for a prolonged period, a customer should use their first outage experience to identify the applicable Block. However, this cannot be guaranteed for the reasons explained above.

Question 6.    What does Stage1, Stage2 and Stage 3 mean?
Eskom has developed a hierarchy of emergency conditions each requiring a specific load reduction stipulated below. Depending on the severity of the supply constraint, Eskom would declare a Stage 1, 2 or 3 Emergency to prevent a national blackout.

Stage 1 –National shortage of 1000MW
Stage 2 – National shortage of 2000 MW
Stage 3 – National shortage of 4000 MW

Please note that eThekwini Stage 1 emergency will affect largely residential & commercial loads whilst Stage 2 will include industrial loads. A Stage 3 emergency will entail all customers with the exception of certain critical resources.

Question 7.    Will load shedding occur every day?

Load shedding is required when the national demand is predicted to exceed the generation capacity connected to the national grid and this can happen at any time depending on the situation causing the incapacity of Eskom to meet the required demand. Whilst, we are most susceptible during the peak times, it is also possible to go into load-shedding during off-peak hours as was the case in May 2008 and on 2 November 2014. These incidences were caused by the interrupted supply of coal to the generation plant and unless Eskom experiences another similar unlikely event we should be able to avoid sustained load-shedding.

Question 8.    Why not load shed at night?
Load shedding has to take place immediately the load is predicted to exceed generation capacity. The load normally exceeds generation capacity during the day when businesses are using electricity and in the early morning and evening when most households are using electricity. Late at night and on weekends when there is low load, there is a less likelihood of the load exceeding generation capacity and hence a less likelihood of load shedding being required.

Load shedding can become necessary at night and on weekends if, for example, Eskom has used the lower load usage during these times to perform essential maintenance on generation plant. In this case the generation capacity will be lower than normal and any additional un-planned loss of generation capacity will result in load shedding being necessary.

Question 9.    Will eThekwini Municipality compensate me for losses?
As covered by the general comments above, eThekwini is simply responding to the national situation and cannot be held liable for any interruption. As no electricity utility worldwide can guarantee supply at all times, customers must provide for the possibility of an interruption of supply at any time.

Question 10.    Why does the schedule provide for 2½ hours for each block?
The principle of 2-hour blocks still applies but some overlap has to be expected to provide for the numerous switching steps involved. At the end of the 2 hours the circuits of the next block have to be isolated before the circuits of the previous block can be restored or this would defeat the purpose of load shedding. The principle of 2 hour blocks still applies but it is necessary to indicate an overlap which could be as long as 30 minutes.

Question 11.    Will I always be in the same block?
Distribution substations are supplied from major substations by multiple circuits and it is possible that the source of supply could be changed for reasons outside of load shedding. While this does not happen often (and usually returned to the normal state after a period), it is possible that this would result in the customer being associated with a different block.

Question 12.    Will you stick to the schedule?
Every effort will be made to follow the schedule, however it must be recognised that abnormal network conditions and unexpected faults cannot b be predicted.

On the other hand, it may not be necessary to switch off all areas in the scheduled block to achieve Eskom’s load requirement at the given time. Areas will only be turned off according to the schedule if Eskom requires the reduction of load.

Question 13.    How long can my freezer stay off before the quality of the food deteriorates?
This cannot be answered directly as it depends on the working temperature of the freezer and the effectiveness of the seals. It is, however, strongly advised to avoid opening the freezer and fridge compartments during an interruption of supply, as this will have a significant affect.

Question 14.    Should I switch off appliances during load shedding?
Ensuring that appliances are switched off during any interruption of supply is advisable, simply because this ensures that they will not turn on when the supply is restored and create an unsafe situation. This also assists the restoration of supply process, as it will avoid high ‘waiting loads’ with the potential to cause an overload trip of an individual circuit. This would require staff to be dispatched to the point of supply and therefore result in an extended interruption.​