Africa is predicted to be the continent that will be most affected by climate change, which is a daily experience in people’s lives. Nowhere in the world is this more likely than Zimbabwe – because of its unique position between two great continental weather systems. One covers the southern states of Africa, where the wet seasons are set by successive cold fronts that sweep across the continent bringing moist air from the Atlantic Ocean. The second is controlled by the Inter Tropical Convergence Zone (ITCZ) which waters the central African region – shifting annually to the north from March onwards, and then moving to the south in October and November.
The ITCZ is forecast to shift 18 degrees north on average and this will affect the southern/central states of Africa most. It may also result in greater precipitation to the north of the equator. This summer we have seen a series of cyclones develop off the Mozambique coast, drawing moisture and rain out of Zimbabwe and causing havoc in Malawi, northern Mozambique and Madagascar.
Overall we can expect more precipitation on average and greater extremes. This has serious implications and I want to consider these here from the perspective of energy security.
Potential energy sources
Zimbabwe has an abundance of potential energy sources – coal bed methane gas, hydroelectricity and solar energy. We have an abundance of coal of differing qualities and the bulk of it suitable for use in coal fired power stations. In addition we have coal deposits suitable for converting into oil and for conversion into coke.
Coal bed methane resources are thought to be considerable but difficult to exploit and unreliable for any large scale ventures. Small (50 megawatt) power plants are a possible option. We have considerable hydro-electricity capacity – mainly located on the Zambezi River. The Zambezi basin already generates some 7000 megawatts from four power stations and this potential could be doubled with additional dams and power stations and river flow barrage based power plants.
Our solar power potential is only limited by demand at the right price (about double current prices per kilowatt hour) and the capital cost.
Regional power pools
The Central African Power Pool is already located in Harare and manages a regional power grid that stretches from the Congo to Cape Town. Total power generated in the region managed by the CAPP is thought to be about 60 000 megawatts with demand growing at about 5 per cent per annum. This means that power demand will double every 12 years or so, calling for very considerable investment in new energy sources to keep the region supplied.
The major issues are:
• Replacing old coal fired plants that are now at the end of their useful lives;
• Bringing into production new power plants;
• Reducing the carbon footprint of the region, which means moving away from coal fired plants;
• Meeting overall power consumption demand at a price that will allow the private sector to compete globally;
• Meeting peaks in demand during the daily cycle and on a seasonal basis; and
• Exploiting both regional and continental potential.
It is clear that historical policies that have attempted to ensure that each country is able to meet its own demand and is secure in that respect, no longer makes sense. To meet and manage future power demand it has become essential to provide for the evolution of regional markets such as that managed by the CAPP.
Zambezi River rise
Power plants need water to operate and this resource is going to become increasingly scarce in southern Africa. Rivers that rise in the more arid regions are going to handle less off run than they have historically. Already long term trends in Bulawayo show that local dams are receiving 27 per cent less average intake than they have historically. By contrast, regional rivers that rise in areas predicted to become wetter will see a rise in average river flow. The Zambezi is the classic example.
This rises in the Congo and traverses Zambia before spilling over the Victoria Falls and it is this region that supplies 85 per cent of the river’s water. This region is predicted to become much wetter and this has significant consequences for infrastructure constructed on the river in the form of dams and hydroelectric power stations. Kariba (2000 megawatts) and Cahora Bassa (4000 megawatts) are examples. Further dams are planned in Mozambique and at Batoka Gorge below the Falls.
The potential of the Zambezi River basin, including the Kafue and the Shire, is considerable and should be exploited to the full. Care must be taken that abstraction for either urban or agricultural use is strictly managed and controlled to protect this potential.
Largest in world
But it is the continental potential of the Congo River basin and the natural gas fields in northern Mozambique that may hold the key to regional demand and supply at affordable prices and on a sustainable and climate friendly basis. The potential of the Congo, one of the greatest rivers in the world and entirely located in a region that is unlikely to be affected by the movement of the ITCZ, is enormous. The potential of a single scheme – the ox bow below Kinshasa is thought to exceed 100 000 megawatts and could become one of the largest power plants in the world. It is also very low cost and clearly must become a priority for the entire region.
The gas find in northern Mozambique is thought to exceed 250 trillion cubic feet and is one of the largest finds in the world. It opens up the possibility of not only regional oil refinery capacity (it is estimated that the field will yield sufficient crude oil to supply the whole of southern Africa) but global demand for LNG and regional demand for electrical energy. Already a north/south pipeline for gas is being planned.
But for these projects to attract the vast capital resources that they require, calls for a stable, reliable and well-managed regional system that has at its disposal high voltage, long distance DC power lines that would feed into the regional and national grids. The CAPP has made an excellent start but more needs to be done before regional States and sources of international capital feel secure and confident to proceed with the exploitation of this potential.
Role of energy
In Zimbabwe it is clear that we will have to pursue all options – it now seems as if the joint Zambian/Zimbabwean Batoka Gorge project will proceed with a potential for 2000 megawatts. We will also proceed with new capacity at Hwange power station (another 600 megawatts) and a new power station (coal fired) for 2000 megawatts at Binga on Lake Kariba. At the same time we are planning a gas fired plant in Mutare and this could be expanded once the north/south gas pipeline is in place.
Solar energy projects on a small scale (100 megawatts) are being considered but are well above current unit costs and this will inhibit development. New technology may overcome this problem but it exists today. Small scale power plants are under construction using hydro potential in the Eastern Highlands and some capacity using bio resources in the South East Lowveld.
Energy, in all its different forms plays a key role in the lives of everyone today. It is our capacity to harness energy effectively that gives us the potential to live lives well above subsistence. Economic growth is simply not possible if we cannot supply our economies and people with energy at the lowest cost possible. This is a huge problem for countries like Zimbabwe that are land-locked and do not have adequate supplies of electrical energy to meet current, let alone future, needs.
Large-scale agriculture
Zimbabwe has a quarter of the world’s chrome and platinum group metals and could supply the majority of the latter and at least a quarter of global demand for the former, if we had the electrical energy to process the product for final shipment – at least 2 400 megawatts of energy would be needed at about 6 cents per kilowatt hour.
We should be converting our railways to electrical energy as the primary source of motion. Cheap power on a reliable basis would also foster the growth of local industry and commerce. In South Africa today 70 per cent of all basic food is produced by just 100 large scale agribusiness companies. In many ways this points the way to the future of food security in a region where global warming is going to make peasant, subsistence agriculture less and less viable.
As rainfall declines across the country and the region and extreme weather (both wet and dry) intensifies, smallholder agriculture will become less and less viable. This means that countries like Zimbabwe are going to have to resort to large-scale agriculture with irrigation and using very sophisticated technologies as the only way that we can feed our people on a sustainable basis. This will require energy to pump water on a very large scale. We need to build more pipelines.
Post published in: Environment