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.

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. This occurrence has been substantially reduced with the new schedule as entire areas are now being switched off at the High Voltage Substations and any change in network configuration would generally be within the same Block.

It is recommended that a customer should use their first outage experience to confirm the applicable Block that they are in.

Question 4.

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, 3 or 4 Emergency to prevent a national blackout.

Stage 1 - National shortage of 1000MW
Stage 2 - National shortage of 2000 MW
Stage 3 - National shortage of 3000 MW
Stage 4 - National shortage of 4000 MW

Please note that eThekwini Stages 1 & 2 will affect largely residential & commercial loads whilst Stage 3 & 4 will include industrial loads.

Question 5.

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 to meet the required demand.

Question 6.

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.

Eskom has also load shed during the off-peak weekend hours in recent months to conserve fuel and water (pump storage) for the high demand weekday period.

Question 7.

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 8.

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 9.

Will I always be in the same block?
Switching is now done at the High Voltage Substation and it is unlikely that there will be a change in Blocks brought about by network re-configuration. However, this possibility cannot be totally ruled out.

Question 10.

Will you stick to the schedule?
The schedule is followed strictly, however under abnormal network conditions and unexpected communication difficulties it may not be possible to switch off/on substation as scheduled. Every effort is made to strictly adhere to the schedule.

Question 11.

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 12.

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.