Electricity in the realm of the lion king (Kelvin Kemm) South Africa

Electricity in the realm of the Lion King

By Dr Kelvin Kemm August 2, 2019 Imagine sitting in the garden on a warm afternoon with a couple of friends discussing electricity supply. You're having a nice cup of tea. The tea is in a cup and the cup, in the traditional manner, is on a saucer.

Someone points out that hydro power is a good way to generate electricity. It certainly is politically environmentally friendly, it does not produce any carbon dioxide, to upset certain people, and it is not complicated. Norway has a large amount of hydro and can claim to have very green energy, which they do.

Hydro is great, on condition that you have the water. In Norway the hydro units can be compared to the tea in the tea cup, on the table. Their dams are constructed in between rather vertical rock walls which form the famous Norwegian fjords and which tower above Norwegian valleys. Many of these geological formations are permanently topped with ice and snow. This ice and snow constantly melt into the dams. Regular rain keeps the water supply plentiful. So, the height of the water in the dam and its volume are essentially constant.

The discussion turns to the challenges of electricity supply in Africa. Africa is huge, far larger than the majority of people realise. Africa is larger than the US, China, India and Europe together. The standard common flat map projection is based on Europe for historical reasons and does not adequately portray the true size of Africa.

Many African countries have very little electricity and one major challenge is their size. South Africa alone is the same size as the whole of Western Europe. The distance from the capital city Pretoria to the southernmost city; Cape Town, is equal to the distance from Rome to London. Many African countries are less than 20% electrified, some only 10%. Many African countries also use a large proportion of hydro power, in fact quite a few are 100% hydro, which is environmentally politically great, similar to Norway. But there is a snag.

The African hydro dams are like the saucer under the tea cup. They tend to be very wide flat expanses of water. Many African countries tend to be rather dry, and so evaporation off the saucer-surface is dramatic. The only way that the dams are filled is from periodic rainfall, not a constant ice and snow runoff. Rainfall can be really ‘periodic’ and dam levels can fall fast when drought conditions set in. In South Africa large dams are built to accommodate droughts of up to 5 years. A year ago, a number of South African dams were down to 15% full. Cape Town started to prepare for a drinking water emergency. Thankfully some rains came just in time to stave off real trouble. In South Africa the issue was with drinking water, not so much with electricity because South Africa has a relatively small percentage of hydropower. But as of writing the large Kariba Dam in Zimbabwe is only 25% full and it is very important for Zimbabwean electricity production. They are very worried.

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Very wisely many African leaders have said that they cannot possibly continue to plan 21st Century economies on African hydropower. Mother Nature cannot be cajoled into arranging for more rain.

Another problem with expanding African hydropower is that all the cheapest sites were used first. For hydro one has to build dams where it is possible to dam some geological feature to create the dam. Due to the size of Africa each potential new site is very much further away from the consumers, or is a major engineering challenge, due to the lack of Norwegian-style fjord rock walls.

South Africa happens to be blessed with huge quantities of coal and is a major coal exporter. Coal is continuously moving by rail to a port where it is loaded onto ships by highly effective automatic systems in which entire railway trucks are picked up and tipped upside-down. But most African countries have no coal, oil or natural gas.

So most African countries face a real problem when it comes to contemplating turning a 20% electrified, vast country into say a 75% electrified country.

When I spoke to an African minister of energy, from a landlocked African country, he pointed out that if they imported coal from South Africa the only way to do it would be by overland rail, over a vast distance. To make matters much worse the train would have to cross four international borders. So he said that coal imports were out of the question. The same type of arguments would apply to oil and gas imports through incredibly long pipelines, or by road tankers. The geographical and political risks are just too great.

Some enthusiasts will loudly advocate solar and wind power. It will be pointed out that much of Africa has good conditions for solar power. That is true, but one can't escape the glaring reality that you only get solar for part of the daytime over midday and you get zero at night. You also get next-to-nothing when it rains, or if clouds come over in the daytime. A layer of dust on the solar panels will also knock out a substantial portion of the solar output. An enthusiastic European vendor may tell you to wash the panels regularly. They use automatic water washers. Simple! But Africa has no water to spray daily onto solar panels.

Much of Africa is also prone to violent storms. Hail can sweep over an area, or great winds can blow for an hour or two. African violent storms usually only last a very short time, but time enough to wipe out, or badly damage a huge array of solar panels.

There are undoubtedly special applications for solar, in remote areas, or in providing power to some application which only needs electricity over lunchtime but powering a national grid to a substantial percentage with solar is not it. Also, remember that to produce one megawatt of solar power requires an area the size of a football field.

Somebody in the building business indignantly said to me: "What is wrong with some company putting one megawatt of solar on their roof if they want to?" The answer is; nothing, if you want a football field on the roof for lunchtime use.

The arguments for wind are similar. Wind turbines have to be placed where the wind is found. That can be far from the consumer. Wind is intermittent and seasonal.

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Handling intermittent power, coming and going on a grid, which ideally should be stable, is a constant control nightmare. The wind enthusiasts say that if you put in enough turbines, thousands of them, then the wind is always blowing somewhere.

Well that is not true, for a few reasons. One is that meteorological data show that wind incidence patterns, over very large areas of thousands of kilometres across, tend to vary together. So, low wind over the whole area is not only possible but likely.

Turbines kill birds and bats, by the thousands. With both wind and solar one gets locked into foreign suppliers for supply and much of the maintenance.

The future of the world is nuclear power. Nuclear has a few inherent advantages. It is without doubt the cleanest, greenest and safest form of power production. No matter what you have heard about the 2011 Fukushima nuclear plant when it was hit by the tsunami, the truth is that not one single person was killed or injured by nuclear radiation. Not one. Also, no private property was harmed by radiation.

Another major advantage of nuclear power is that it uses so little fuel. The annual fuel usage of even a large nuclear plant can be carried in a couple of trucks. It can be airlifted-in, if need be. There is no need for long supply lines which can be prone to weather or political disruptions. Nuclear reactors are only refuelled every 18 months.

Critics will say that nuclear is expensive. No, it is not. One has to look at the total life cycle. A modern reactor is designed to last for 60 years and will probably last for 80 years. What is true is that money needs to be spent upfront in the construction, but then the benefit is reaped over the following decades. So, what is required is an innovative approach to the project-cycle funding. Right now in South Africa the nuclear-generated electricity is the cheapest by far. The current nuclear plant, Koeberg, is over 30 years old and is now running very profitably, since the construction costs have been paid off. Another plus is that the price of uranium is almost irrelevant. Such a little amount of uranium is used in a nuclear plant, that even if the international uranium price were to double it makes extremely little difference to the annual fuel bill. It is nothing like a variation in the coal or oil price.

Uranium atoms are known as fissionable atoms which means that they will split or 'fission' reasonably easily, when struck by neutrons. However, there is another metal called thorium which is known as a 'fertile' atom and it lies very close to uranium on the chemical table. With a slight nuclear transformation, the fertile thorium can be converted into a form of fissile Uranium which does fission.

So thorium can also be used as a nuclear fuel. There is much more thorium on the planet than uranium and it is much more widely spread around the world. So thorium provides hundreds of years’ worth of extra nuclear fuel availability. There are two other major advantages of thorium. One is that the nuclear waste that results from thorium is much milder than the waste resulting from uranium. The other is that while it is very difficult to produce nuclear weapons from uranium, without very sophisticated technology, it is impossible to produce weapons from thorium. So from a potential weapons proliferation point-of-view thorium can be readily distributed around many countries without ramping up international political fears.

The world's richest thorium mine is in the Western Cape region of South Africa and it is called Steenkampskraal. Some of the earliest gas-cooled reactors in the US and 3

Germany developed in the previous century, were fuelled by thorium.

Steenkampskraal mine supplied thorium to a few countries at that time.

Large-scale nuclear needs water cooling which means that it has to be built on a coastline or on a large inland water source. But big nuclear is probably too large for many nations to start with. There is a second solution. There are smaller reactors which are currently being developed called the SMR-class. SMR is Small Modular Reactor. The South African PBMR is an SMR. The PBMB is Pebble Bed Modular Reactor and one nuclear power station can be only 10% the size of a large one. A PBMR does not need large water cooling, so you can place it anywhere you like. In fact, close to the point of consumption is no problem. The 'Modular' means that you can add extra reactors to the initial system, as you wish, when you wish. It is something like adding extra locomotives on a large train, but all controlled by one driver.

Obviously a PBMR is considerably cheaper than a large reactor. So, a very viable answer for any African country is to plan for PBMR nuclear systems. One PBMR reactor will produce 100 to 200 Megawatts, depending on its design. The PBMR reactor was developed to be able to use uranium or thorium fuel.

An important consideration with nuclear power in Africa is for countries to work together. Africa needs a nuclear network for operations, training and for general nuclear development. In the spirit of the Fourth Industrial Revolution thinking, now is the time to plan an African nuclear network. Thankfully a number of African countries have already started.

Dr Kelvin Kemm is a nuclear physicist and CEO of Nuclear Africa (Pty) Ltd, a project management company based in Pretoria, South Africa. He also does consultancy work in strategic development of various industries.

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