Energy-crisis myths, misrepresentations and fallacies

Bryan Hadfield, Mail & Guardian, “Thought Leader”, 25 March 2008

Much of the recent reporting on the Eskom crisis is based on a poor understanding of the true nature of the energy problems and what would constitute useful responses from the public. Half-truths, disingenuous excuses, obfuscation and myths abound.
  • Turning off your hot-water cylinder for a few hours a day saves large amounts of energy: It does not. It mostly just defers the use of that energy until you turn it back on.
  • Load-shedding has to be done because people are using too much energy: A half-truth. Load-shedding has to be done because too many people are using too much energy at the same time and Eskom did not act to increase its generating capacity to match the predicted demand for electricity.
  • Unseasonable rain wetting the coal has been a major factor: Well, yes; but only because misguided reductions in normal stockpiles and mismanaged supply contracts resulted in coal stockpiles running so low that Eskom was forced into trying to handle large quantities of the finely crushed coal dust that collects at the bottom of the heap and which becomes a conveyor-clogging slush when it is wet.
  • Growth rates in the economy have exceeded all expectations. We are victims of our own success: Not true! Growth rates have been below target values set by the government, and the forecasts made in the 1990s correctly predicted the need for additional capacity to be brought on line by 2007.

So what are the real stories and what can be done?

Government policy with regard to the electricity-supply industry delayed the construction of new power-generation plants. Warnings that new, large power stations would be needed by 2007 or 2008 and that they would take 10 or more years to plan, build and commission were ignored or not believed. Eskom has been complicit in allowing the situation to reach crisis levels by failing to lobby the government forcefully enough and by not making sure that the politicians understood the inevitable and economically catastrophic consequences of delays.

Did Eskom senior management have appropriate electricity-supply-industry backgrounds and the experience to appreciate fully the need for urgent action and the consequences of failing to maintain an adequate margin between peak generation capacity and peak system load? Possibly it did not.

Eskom adopted aggressive affirmative action and black empowerment policies. Meeting racially defined quotas was given much greater importance than retaining and employing skilled and experienced personnel. This applied as much at the top as elsewhere, or perhaps even more so. Highly qualified and very experienced people with years of service in senior positions were encouraged to retire early to make room for these policies to succeed. In a highly technical, complex and strategic industry, this was a particularly dangerous strategy. No matter how politically frustrating it may be, there is no substitute for appropriate experience, and unfortunately it still takes 20 years to get 20 years’ experience.

Exacerbating the present crisis is the age of much of the infrastructure as well as inadequate capacity in parts of the network. Transport of power to the points of consumption, particularly when equipment failures occur, becomes an aggravating factor. Large parts of the present infrastructure were built in the 1960s, 1970s and early 1980s. Much of the equipment is now 40 to 50 years old and approaching the end of its useful life.

A fundamental and poorly understood characteristic of the electricity-supply industry is that large quantities of electricity, the quantities needed to supply big cities and heavy industry, cannot be economically stored. It must be manufactured at the same time and in the same quantities as it is being used. Turning something off does not allow electricity to be saved and made available later. It simply means less electricity has to be generated now, but it will have to be generated when the load is turned back on.

Another poorly understood issue is the magnitude of the loads and the capacity of the generating plant needed to power a modern economy. Renewable resources are at present unable to provide power on the scale that it is needed for many purposes. Nine hundred large wind turbines would be needed to match more or less the output of the Koeberg nuclear power station. The Western Cape at present uses more power in peak periods than two Koebergs can produce. The balance is imported from stations in Mpumalanga via Eskom’s 400kV transmission lines.

The wind turbines needed to meet this load would probably occupy more than 2 000ha of land, and they only work at full capacity when a good, strong breeze is blowing. You cannot place them too close to each other or one behind another because they affect each other. And, of course, you cannot store their output for use when the weather is calm.

When it comes to solar panels used to generate electricity, not to be confused with solar water heaters, it is definitely no contest. Nearly 2 000ha or 20 square kilometres of solar panels would be needed to match Koeberg’s output. They produce direct current at low voltages, and expensive inverters would be needed to turn that into the alternating current necessary for economical transmission and distribution. And then, what do you do at night? Remember you cannot store electricity economically in large quantities.

So where do we go from here? It’s a big problem, which reminds me of the story of the traveller asking for directions and being told: “You can’t get there from here.”

We are not the only country needing to build new, large-capacity power stations urgently. The additional capacity we need over the next two decades pales into insignificance compared with the needs of countries such as China and India. An international shortage of skilled artisans and engineers is making it difficult to recruit skilled staff and easy for existing technical staff to find lucrative employment elsewhere at highly competitive salaries. Insisting on meeting racial quotas and applying preferential procurement and promotion policies is not helpful.

In the short term, we need to do two things. The first, and most important, if we are to avoid or reduce the need for load-shedding, is to spread our consumption of electricity more evenly over the day and avoid, as far as possible, consuming energy during the morning and evening peak periods. Isn’t it strange that Eskom has not clearly and unambiguously told us this and told us exactly when demand is normally at its highest? Gee, guys, it does, after all, follow a similar pattern every weekday with timing variations between summer and winter. Pretty warning gauges on TV are all very well but don’t allow us to plan ahead.

So, yes, turn your hot-water cylinder off in the late afternoon and turn it back on after 10pm to heat the water you used showering after your evening run, washing the dishes and so on. This may not save much energy, but it will defer its consumption into the low load period in the late evening and at night. There should be plenty of hot water for a morning shower if that is your preference.

Now comes the hard part. If you prefer to shower or bath in the morning but also need hot water in the evening, you need to replace any hot water used by switching the cylinder on during the day when the peak load on the national grid occurs — but when? Why don’t you tell us, Eskom? A better plan is to change your habits and shower or bath in the evening, reheating the water overnight.

Then we also need to be careful. If we all turn our cylinders back on, say between 10pm and 11pm, we will generate a new peak, which could be as big a problem as the present situation. It needs a proper plan. If no hot water is used during the day, leave the cylinder on so that there is enough hot water ready for you when you get home. The thermostat will make sure that the cylinder only turns on for a few minutes at a time once or twice during the day, particularly if it is well insulated, so make sure you install a geyser blanket. The on-and-off operation during the day is not a big problem because it only lasts for short periods. As long as no hot water is used, you are only replacing the small amounts of heat energy that leaks through the insulation. There will almost always be timing differences between the thousands of cylinders in South African homes, spreading the load fairly evenly through the day.

To save significant amounts of energy you have to reduce your consumption of hot water or use solar water heating. You can fit low-flow shower heads, you can shower instead of bathing and you can insulate the hot-water pipes between the cylinder and the hot taps so that you don’t have to run off litres of cold water before the hot water arrives and then let the hot water in the pipe go to waste and get cold when you turn the tap off.

Run your washing machine and dishwasher, if you use them, after 9pm rather than during the day. If you can afford it, use a dishwasher instead of washing by hand. Make sure it is full before you run it. Wash clothes in cold water; very few modern fabrics have to be washed in hot water to get them clean. Use compact fluorescent lamps to replace old-style incandescent lamps to reduce the load on the electricity network during the evening peak.

But understand that although these measures will help for a while, they are not a solution to the electricity crisis. They are a delaying tactic. The government and Eskom must use the time they buy wisely. Once we have taken all reasonable and affordable steps to reduce energy usage and defer peak-period consumption, this opportunity is no longer available. If they spend the time we buy them in endless debates and political bickering, if they continue to prioritise meeting BEE and affirmative-action employment targets over skills retention, experience and competence, then it will very quickly be too late. We will be back where we are today, but worse off because we will have no short-term options left.

The load on the electricity network is growing all the time. If the economy is to continue to grow and provide more employment and a better quality of life, then electricity consumption must and will grow too. The reserve margin is currently around 6% compared with an internationally accepted norm of 15%. Unless even more new power stations are built and other measures are taken to increase the supply of electricity, the present situation is going to deteriorate.

In an interview with the publishers of a number of respected technical journals in February, Eskom’s CEO, Jacob Maroga, provided figures that seem to indicate that if Eskom builds everything it is planning to build and it is all commissioned on time, as planned, the reserve margin will fall to 3,5% by 2014.

What does this tell us? What kind of a solution is that?
  • Bryan Hadfield is a graduate electrical engineer. He spent 30 years with one of the larger South African mechanical and electrical engineering consulting practices, of which 15 were in a senior management position. For the past eight years he has been practising as an independent engineering consultant specialising in the design and management of public lighting systems, the design of bulk power-supply networks for selected industrial clients and in engineering forensic investigations for the insurance industry


1950 words