PowerAlert Forums – – Load Shedding Questions & Answers – From #Eskom

PowerAlert Forums :: View topic – Load Shedding Questions & Answers – From Eskom.

Load shedding – frequently asked questions (FAQs

1. What is load shedding?
Load shedding is a last-resort measure to prevent the collapse of the power system countrywide.

When there is insufficient power station capacity to supply the demand (load) from all the customers, the electricity system becomes unbalanced, which can cause it to trip out countrywide, which could take days to restore. When this occurs, Eskom can either increase supply or reduce demand to bring the system back into balance. As the difference between supply and demand becomes small, we refer to the system becoming “tight”, which implies that there is a need to take action to prevent the system from becoming unstable.

Eskom follows a sequence of steps to keep the system stable and to avoid load shedding except when it is absolutely necessary as a last resort.

1) Eskom will run its power stations at maximum available capacity and bring “peaking plant” (hydro stations and open-cycle gas turbine (OCGT) stations) on line to increase supply. However, under the current conditions of capacity constraints, there are severe limitations on Eskom’s capacity to increase supply. Therefore, the need to reduce demand becomes inevitable.

2) Eskom is appealing to all customers to voluntarily reduce consumption by 10%. This results in a reduction in demand, which makes a huge difference to the “tightness” of the system. In recent weeks, the cooperation of mines, large industries, and other customers in reducing consumption by 10% has resulted in there being no need to carry out load shedding on the scale of that which was experienced in January 2008.

Load reduction through efficient use of energy is preferred to load shedding.

As the benefits of voluntary customer load reduction are achieved,
the extent of scheduled load shedding will be reduced.

3) On days where the system is “tight” (due to insufficient supply capacity because of maintenance or faults, and the 10% reduction being insufficient to compensate), Eskom needs to reduce demand still further. It does this by interrupting supply to large industrial customers who have special contracts with Eskom that allow this to be done. These demand market participation (DMP) customers can cope with being switched off, as long as the interruption does not exceed specified periods, or can reduce part of their load, provided they are not switched off completely.

4) When all other options at its disposal have been exhausted, and if the demand still exceeds available supply, Eskom will be forced to cut supply to other customers. This process is called Scheduled load shedding.

Scheduled load shedding is a controlled way of sharing the available electricity between all customers. By switching off parts of the network in a planned and controlled manner throughout the day, the system remains stable throughout the day, and the impact is spread over a wider base of customers.

Load shedding schedules are drawn up in advance to describe the plan of how parts of the network will be switched off in sequence during the days that load shedding is necessary.

On days that load shedding is required, the networks are switched according to the predetermined plan to ensure that, as far as possible, customers experience load shedding in accordance with the published load shedding schedules.

In exceptional circumstances, if scheduled load shedding is not achieving the required load reduction and/or unexpected emergencies or failures occur, then Emergency load shedding may be required. System control centres will then shed load using emergency switching in order to protect the network. Such events are rare, but if a state of Emergency load shedding is required, then all customers can expect to be affected at any time, and the planned schedules will not necessarily apply.

2. How does load shedding work?
The load shedding schedules have been simplified in order to:
• make the schedules easier to understand and remember;
• improve our ability to adhere to the planned schedules;
• improve the stability and consistency of the schedules;
• improve the predictability of being switched off;
• improve the communication of the schedules and the status of the power system; and
• make the impact more equitable across the entire customer base.

Load shedding has been simplified to one stage, called “scheduled load shedding”:
• There are no longer the confusing stages 1, 2, and 3.
• On days that load shedding is required, a single, fixed plan of load shedding schedules will go into operation.
• These schedules are published in advance so that customers can familiarise themselves with the days and times when they will be affected if load shedding should be required.
• There are different schedule times for alternate days of the week. One set of times operates on Mondays, Wednesdays, and Fridays. The other set operates on Tuesdays, Thursdays, Saturdays, and Sundays. This is done in order to spread the impact more equitably between customers.
• Period of load shedding:
o Load shedding will only occur when required by the system.
o Eskom will predict the “tight” periods in advance, and a fixed period for scheduled load shedding (for example, two weeks) will be identified up front and communicated to customers in advance via the media.
• Length and frequency of outages:
o The schedules have been designed so that each customer will experience, on average, not more than two hours of disruption every second day.
o Scheduled load shedding will take place only between 06:00 and 22:00.

Emergency (unplanned) load shedding can occur during network emergencies:
• This will happen rarely, if ever (and is always a small possibility in any power network, even without the current capacity constraints – for example, the incident in Florida, USA, during February 2008).
• All customers could be affected.
• The scheduled load shedding schedules will not be adhered to, as in the event of a “catastrophe”, the technical requirements of the power system need to receive priority, and this will determine the sequence in which parts of the network are switched.
• For these reasons, a schedule will not be published for emergency load shedding, and the media will be the main channel used to keep customers informed.

3. Exemption from scheduled load shedding
The country has now entered the second phase of the National Emergency Response Plan, the power rationing phase, which will extend from March to July 2008. This means that Eskom is now looking to the commercial sector and residential and other smaller customers to save 10% of their consumption and reduce demand.

For customers who are individually switchable (see note *), should a 10% demand reduction be achieved, these customers will be exempted from the load shedding.

In the case of embedded customers (see note **), who are not individually switchable, a group achievement of the 10% reduction will lead to an exemption of that group from load shedding. Although selectively switchable critical loads or services will be exempted from load shedding where possible, they still have to achieve the set 10% demand reduction.

The period that will be used to set the base consumption level, from which savings have to be achieved, is October 2006 to September 2007.

Given the key principle of equity, key industrial customers, municipalities, and high-voltage industrial or commercial customers that are selectively switchable can apply for exclusion from scheduled load shedding once savings have been achieved.

Scheduled load shedding will commence on 31 March 2008. In the run-up to the implementation of this programme, the following dates will assist all customers with their planning for the load shedding. On 17 March 2008, the proposed load shedding schedules will be published. From that date to 21 March 2008, all municipalities and key industrial customers will be in a position to apply to Eskom for exemption from load shedding on the back of prior recorded savings or a concrete implementable demand reduction programme. On 24 March 2008, the revised load shedding schedules that exclude the exempted customers will be published. The load shedding will then begin on 31 March 2008 according to the revised schedule.

Every two weeks, Eskom will benchmark individual contracted reduction to ensure that each customer is achieving the committed reduction that allowed it to be exempted from load shedding. If over two benchmarks periods, the reduction is not achieved, the customer will be reprogrammed into the load shedding schedule. A protocol to discuss this reprogramming to the schedule will be established.

Eskom aspires not to implement load shedding and, therefore, requests all customers to engage with the load reduction programme required.

Notes:

* “Switchable customers” means those customers over whom the electricity supplier has direct control from its control rooms. The electricity supplier would, therefore, be able to isolate them and switch them off or avoid switching them off depending on their performance in terms of savings.

** An embedded customer is supplied via the Eskom network at reticulation levels or via another supplier, for example, a smaller municipality that gets its electricity from a metro or a house in a township or a suburb or a large power user such as a factory. It is, therefore, a customer who cannot be isolated during load shedding.

4. When will load shedding commence?
• Scheduled load shedding will commence on 31 March 2008. On 17 March 2008, the proposed load shedding schedules will be published. From that date to 21 March 2008, all municipalities and key industrial customers will be in a position to apply to Eskom for exemption from load shedding on the back of prior recorded savings or a concrete implementable demand reduction programme.
• On 24 March 2008, the revised load shedding schedules that exclude the exempted customers will be published.
• Every two weeks, Eskom will benchmark individual contracted reduction to ensure that each customer is achieving the committed reduction that allowed it to be exempted from load shedding. If over two benchmark periods the reduction is not achieved, the customer will be programmed into the load shedding schedule.

5. How can I stay informed regarding load shedding?
It is important for every customer to know where to find the following information:
• The status of the power system on a daily basis (Is load shedding happening/likely to happen in the country today?)
• The next “tight” period when scheduled load shedding will take place (What is the outlook for the country for the next few weeks?)
• The scheduled load shedding schedules (When exactly my power will be cut during scheduled load shedding periods?)
• Changes to the schedules (Has my schedule changed?)

The current status of the power system is available on:
• the Power Alert dial on the websites www.eskom.co.za and www.poweralert.co.za;
• SABC TV Power Alert broadcasts in the evenings; and
• daily power status broadcasts on regional radio stations.

The notification of the next scheduled load shedding period will be carried out by means of:
• notice on the Eskom website www.eskom.co.za;
• SMS notification to Eskom customers;
• daily power status broadcasts on regional radio stations; and
• notification in the press.

The detailed scheduled load shedding schedules are available:
• on the Eskom website www.eskom.co.za;
• in the press (to cut out and keep);
• by SMS and email notification for Eskom customers; and
• on request from the Eskom Contact Centre on 08600ESKOM (0860037566).

Keep updated on changes to the schedules, which may take place from time to time:
• on the Eskom website www.eskom.co.za;
• in the press (to cut out and keep);
• by SMS notification for Eskom customers; and
• on request from the Eskom Contact Centre on 08600ESKOM (0860037566).

Ad hoc deviations from published schedules due to operating issues that may arise from time to time will (where possible within the constraints of the time available) be advised:
• on the Eskom website www.eskom.co.za;
• by SMS notification for Eskom customers; and
• on request from the Eskom Contact Centre on 08600ESKOM (0860037566).
6. What is the difference between load shedding and saving electricity?
Load shedding is aimed at removing load from the power system when there is an imbalance between the available generation and the demand load. If we did not shed load, then the whole national power system would switch off and nobody would have power. Load shedding is, therefore, done to protect the national power system from collapsing.

Saving electricity (through using efficient appliances, switching off equipment when not in use, and using alternative sources of energy such as solar geysers) has benefits such as reduced cost, reduced pollution, better use of natural resources (coal, water, and fuel), and less wear and tear on the power stations and transmission and distribution systems − and it saves customers money.

In these times of capacity constraints, saving electricity also means that the load on the national power system is reduced, thus helping with the balance between available generation and the demand load, thereby reducing the risk of load shedding.

Therefore, saving electricity can help to avoid load shedding taking place, especially if customers switch off unnecessary appliances and loads during peak periods and at other times when the risk of load-shedding is high (Power Alert goes into orange, red, or brown).

7. How did load shedding come about? What happened?
Over the last decade, South Africa has experienced a steady growth in the demand for electricity on the back of a robust economic growth. The continued growth in the economy has exhausted Eskom’s surplus electricity generation capacity and reduced its reserve margin progressively. We expect the reserve margin to continue on a downward trend for the next seven years until new base-load power plant is built (2014). In spite of new capacity coming on line, which includes bringing back mothballed power stations and building open-cycle gas turbines, the demand is still higher than available capacity. Eskom is accelerating the implementation of this capacity expansion programme and will invest in excess of R300 billion over the next five years in the upgrading of South Africa’s power supply infrastructure. The biggest percentage of the expenditure will go towards improving generation capacity through, among others, building new power stations.

Until we can build the necessary capacity, and unless we can substantially reduce national demand, there will be times where load shedding becomes necessary in order to protect the electrical power system.

8. What are Eskom’s short-term plans, not long-term as in building power stations?
• Improve load-shedding schedules, accuracy, quality, equity, and adherence to schedules.
• Improve suburb search (navigation) on the website.
• Improve agent training and increase the number of agents in the contact centres.
• Liaise with the municipalities on an ongoing basis.
• Develop other channels of communication, such as regular schedules published in newspapers, an SMS notification service, and a voice-response system to handle queries.
• Encourage saving of electricity – using electricity sparingly.
• Investigate and implement alternatives to load shedding, such as power rationing.
• Improve transparency and communication.
• Work with customer groups and stakeholders to find and agree on acceptable solutions.
9. If Eskom has a capacity problem, why are metro/municipality customers affected?
The electricity consumed by metro/municipality customers is generated by Eskom power stations and transmitted across the country, where it is sold in bulk to metros/municipalities who, in turn, distribute and sell it to their end customers.

So, if Eskom faces capacity problems, it not only reduces load among its own customers, but it also asks the municipalities to reduce load, and they, in turn, activate load shedding among their customers.

10. Where do I find out when I will be shed?
Load shedding schedules for Eskom areas and most metros/municipality areas are published on the Eskom website www.eskom.co.za and are being published in major newspapers. Information is also available from the Eskom Contact Centre on 08600ESKOM (0860037566).

11. The schedules on the website/in the newspaper are not accurate − in reality, the power goes off at different times to those published and is off for longer than the scheduled time. Why is this?
While we are trying to make the schedules as reliable and accurate as possible, there are inaccuracies due to the following:
• Most networks do not coincide exactly with area boundaries such as suburb boundaries. There will, therefore, always be a margin of error, as two customers living in different parts of a suburb can be fed by different networks, which are switched off at different times.
• The schedules, as published, are a plan of what we intend to do in the event of a power shortfall. In reality, operational reasons sometimes cause the engineers to have to switch networks differently from the plan. We try to minimise this as much as possible and stick as closely as possible to the schedules as published. We are also working on ways to inform customers when we have to deviate from the published schedules.
• There are occasions when the power is off longer than stated in the published schedules. The usual cause of this is that when the engineers attempt to switch the power back on, either the remote control switches sometimes do not operate, meaning that field staff have to drive out to switch customers back on manually, or sometimes network faults happen on re-energisation due to the surge. Field staff then need to physically go out and fix the fault.

12. Why are not all suburbs/areas listed in the schedule?
The Eskom schedule information is based on our network and customer databases − and since we do not have complete coverage of the whole country, not all areas are listed.

The municipality/metro information on our site is provided by them and is subject to similar constraints.

We are busy with a new website (target end March), and this will be organised according to the official South African government database of regions, towns, and suburbs.

13. Not everyone has access to the Internet. How can they find out the information they need?
Schedules are also being published in the major newspapers. We suggest that customers cut these out and keep them for future reference, so that they are aware of when cuts will take place should it be necessary to go into load shedding.

In addition to this, we are expanding a range of electronic communication channels to improve access to the information:
• We are using our existing outage management SMS campaign system to notify Eskom customers. It is important that customers keep us up to date when they change their cell phone numbers. There are sometimes delivery delays on the cellular networks due to congestion when large numbers of SMS messages are sent.
• We are developing an additional SMS service where Eskom and other customers can request to be kept informed by suburb.
• We are investigating using other technologies such as email, a self-service automated phone-in system, and various cell phone technologies, including a mobile website.

The contact centre is not the recommended method for finding out about schedules because it often means waiting in a frustratingly long queue. The agents only have access to the same schedules as published on the Web. However, we acknowledge that some customers do prefer to call, so we have employed more agents, who have been trained on how to handle load shedding issues, and we have improved systems to improve the information available to the agents, as we know there were shortcomings in all these areas.

14. The municipality/metro information is not as complete as the Eskom information
We are working with all the municipalities and metros to improve this. The intention is for all the communication channels mentioned above to provide the information for Eskom and municipality/metro customers.

15. Why are some customers switched off for longer than the published times on the schedules and sometimes more that once a day?
Most customers are switched off according to the published schedules because we normally use remote-controlled switches to control the network. However, some customers are switched off for longer than published in the schedules because, if the remote switching fails to operate, due to failure of the switching equipment or the telecommunications links, we have to send out technicians to do this switching manually, and in these cases, we may overrun the scheduled times.

Another possible cause of time overruns is that when we re-energise the network, there are large surge currents that flow, which can damage our network equipment or cables, meaning that we need to send out field teams to find and repair the fault before power can be restored. Customers should please switch off all apparatus and appliances during an outage in order to minimise the effect of this surge and also to protect their own equipment against possible damage. Leave only one light on in order to know when power has been restored.

Some customers are switched off more than once a day because, in some parts of the country, we do not have enough “blocks” of load to achieve the desired reduction throughout the day by switching off each block only once. We then have no choice but to switch off the same areas more than once to achieve load reduction throughout the day. This issue is being addressed in the design of new schedules to be released in March.

16. Why are some customers not experiencing load shedding at all, yet in other areas the same customers are shed over and over again?
We have agreements with certain large customers that they will reduce a significant percentage of their load when we go into load shedding, but we still need to keep their power on during these times. Also, we do not shed critical entities that directly contribute to the continuity of power supply, for example, coal mines, oil refineries, water supply pumps, etc. It could be that other customers are connected to the same network feeding these large or critical customers, and since we do load shedding switching by network (it is practically impossible to switch individual customers), these other customers would benefit by not having their power cut.

We are responding to customer concerns by revisiting our load shedding principles and protocols and revising schedules where we can to ensure more equity. These issues are being addressed in the design of new schedules to be released in March.

17. Why are customers not informed well in advance, and why can we not provide a forecast for future load shedding events for customers to plan accordingly?
Eskom forecasts the future outlook for the days, weeks, months, and years ahead, based on load growth projections and planned maintenance of our power stations. These outlook forecasts show that load shedding is likely to happen on a regular basis into the future until the reserve margin is adequate.

We are using various media channels to keep the public better informed about the outlook, which will give customers a better idea of what days load shedding is likely to happen. We also publish the schedules in advance, so that, if load shedding should happen, customers will know at what time of day they are scheduled to experience power outages.

Customers should assume that load shedding will take place in accordance with the published schedules and, therefore, plan accordingly.

However, on any given day, the situation could change at a moment’s notice due to an unforeseen fault, resulting in additional emergency load shedding being necessary.

18. How do these schedules, colours, and stages work?
The Power Alert colours represent the balance between supply and demand on the power system. When the colour reaches brown, the system is in a critical state, and unless enough load is reduced voluntarily, load shedding will start.

The schedules are a predetermined set of schedules (including 30 minutes’ overlap time to allow for switching) that give the time we would shed each area if load shedding is necessary. When we need to shed, we try and stick to these schedules, so that customers know what to expect if shedding starts.

To spread the impact of load shedding more equitably, there are two sets of schedules, one applicable to Mondays, Wednesdays, and Fridays, and the other applicable to Tuesdays, Thursdays, Saturdays, and Sundays.

In the previous schedules, there were three stages, which related to how big a problem (that is, shortfall) existed on the national power system:
Stage 1: up to 1 500 MW.
Stage 2: up to 3 000 MW.
Stage 3: up to 4 500 MW.

These schedules were a source of confusion to customers, and the new schedules to be published in March have been simplified, and the confusing stages have been removed.

We will be refining these schedules all the time, so please always refer to the latest on the Web or in the press.

19. Can load shedding time be negotiated?
In general “No”, since we cannot negotiate at an individual customer level. However, in compiling the schedules, we have tried to take into account as far as possible factors such as peak periods, business hours, and the nature of life and work in the various areas and communities. The reality is, when necessary, we have to remove load from the system, and we can never do this in such a way that it will not inconvenience somebody, somewhere.

We do not have the flexibility that we have when negotiating planned outages for maintenance of our lines, which many customers have been used to in the past.

We are, however, taking into account all the inputs received from our customers in refining the way we do load shedding in order to take into account as many of the concerns raised as possible, within the constraints of technical limitations and the realisation that it is impossible to satisfactorily meet the needs of every customer.

20. What about customers with special needs?
Customers with special needs such as medical support equipment (ventilators, dialysis machines, etc.) should consult their medical practitioner on what special arrangements can be made. For example, it may be possible to obtain a battery back-up unit for medical equipment or obtain additional oxygen cylinders as a back-up.

It is generally impossible to leave individual customers on when whole networks and areas are switched off, so customers with medical needs must please take extra precautions to ensure that their needs are provided for and that they are prepared to deal with power cuts.

21. What will be affected by power outages?
The following will not be available when the electricity supply to your home is switched off:
• Geyser and hot water supplies
• Cookers, electric kettles, microwave ovens, and refrigerators
• Lights
• TV and hi-fi equipment
• Electrically motorised security gates and garage doors
• Pool pumps
• Personal computers
• Electric air conditioning
• Electric alarm clocks
• Household electric pumps for irrigation or plumbing systems
• Electrically operated ignition systems on certain gas appliances
• Automatic electronic control systems and time clocks
22. What will usually not be affected by power outages?
• Security systems that have battery back-up (some may go off due to the interruption)
• Telephones that are not reliant on mains electricity (answering and fax machines may, however, be affected)
• Cell phones
23. What advice do you have to help me cope with power cuts?
Hints and tips in case of power outages
Eskom has a short-term power supply shortage, while at the same time experiencing higher than expected demand. From time to time, this may result in power outages – what is termed load shedding – for short periods across the country. The more electricity South African consumers can save by switching off non-essential appliances or not switching them on at all, the fewer power outages there will be. Below are hints and tips to assist you in case of power outages.

Switch it off
If the power goes off, it is safer to simply turn off (or even better, disconnect) any electrical appliances that you were using. Keep one light switched on to alert you when the power returns. Clearly mark on/off switches with a piece of masking tape. When the power comes back on, it may do so with a momentary surge, which may damage electronically controlled appliances such as computers, televisions sets, VCRs, DVDs, etc.

Remember to reset time control clocks on cooking ovens, pool pumps, geysers, and other automatically controlled appliances, unless these are battery operated. Also remember that householders are responsible for all electricity usage and appliances in their homes.

Useful tips to minimise inconvenience when the power is off
Think about communication: ensure that your cell phone is always fully charged when power is available.

Think about transport: ensure that your vehicle (car, “bakkie”, motorcycle, etc.) always has fuel in the tank, since, during power outages, petrol stations cannot pump fuel.

Think about cash: ensure that you have adequate cash as auto tellers cannot operate without electricity.

Think about access, security, and safety:
• Release automatic electric garage door mechanisms to allow you to gain access to your property during a power outage.
• Release electric security gates and switch to manual operation to avoid being either locked out of or into your home.
• Keep temporary lighting readily available, for example, electric torches, candles, etc. Be sure to locate these items in places where they will be easy to find in the dark.
• Keep a torch (with fresh batteries) by your bedside at all times.
• Obtain a small LP gas lamp, as they provide good quality lighting for a large area.

Think about keeping things cool and heating them up:
• Boil water and keep it in thermos flasks for hot drinks for when the power is scheduled to be switched off.
• Use a thermal cover on teapots and other pots and pans to keep drinks hot and meals warm.
• Prepare meals beforehand in readiness for periods when there will be power cuts.
• Obtain a small stand-by bottled LP gas heating ring for essential cooking and to boil water for hot beverages.
• Keep adequate stocks of essential foodstuffs.
• Keep refrigerator and freezer doors closed. A power outage of four hours should not cause food spoilage, and a freezer should keep frozen food safe for at least a day. It is a good idea to have available alternative snacks that do not need refrigeration.
• Most medication requiring refrigeration can be kept in a closed fridge for several hours without spoiling. (To be sure about this, check with your doctor or pharmacist.)
• Fill plastic containers with water (still leaving some space inside each container for expansion during freezing) in a deep freeze or the freezer compartment of your fridge. This (frozen) water will help keep food cold during a power outage.

24. How do we tell the difference between a power fault and load shedding?
When the power goes off, it is not possible to know whether it is a fault, emergency load shedding, or scheduled load shedding, except to refer to the published schedules.

If an outage occurs at a different time to the published schedule or goes on longer than the published time, and emergency load shedding is not being publicised in the media, it should be treated as a fault.

Customers must always check the load shedding schedules, and any outage not coinciding with these MUST be reported as a fault. Do NOT assume that it is load shedding. Eskom staff must ALWAYS assume it is a fault, unless it coincides with confirmed load shedding.

25. Why are the municipality customers referred to Eskom?
We are concerned about this, which is happening in some cases, and we are liaising with the municipalities concerned. Municipalities should be able to assist their direct customers with information on their own schedules. However, as a service, we aim to include all the municipal schedules on our own website.

26. What are we going to do in 2010 if we cannot provide enough electricity now?
FIFA regulations require that all stadiums and other key installations, such as media and communications centres, must have their own generated power. The utility power is regarded as a back-up. This applies to any country in the world where the World Cup is held and not just to South Africa.

The key installations for the 2010 World Cup lie within the host cities and are supplied by the municipalities, so Eskom is working with the municipalities as part of the Eskom 2010 strategy. We have a dedicated executive focusing on 2010, supported by a dedicated team consisting of subject matter and operational specialists.

27. What about winter?
Winter will continue to be a challenge due to the higher loads, but, on the other hand, planned maintenance of our power stations is done during summer (hence the present shortfall) so that we have maximum generation capacity available during the winter season.
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Please note, that the light at the end of the tunnel might be an oncoming train…

Best solution : LEAVE THE COUNTRY!