First published 30 March 2016
So SA is projecting to put R64 billion into this long proposed DRC hydroelectric scheme. The project has always sounded appealing – about 26,400m3/sec falling approximately 150 metres, with a potential therefore of around 39GW which I would estimate as roughly Southern Africa’s present total consumption (which is not the same as total demand!). One wonders though how the planners have modelled the political risk aspect of the project in DRC and the countries through which the 2500MW will be transmitted. It is not just the stability of the countries but also their ability to hold SA hostage. Issues round Russian pipelines come to mind. I recall my surprise on going to the Italian Alps around 1960 and learning that elements in the German speaking parts (earlier part of Austria) were blowing up pylons as part of their protest and at another time encountering army checkpoints on paths over Alpine passes to discourage infiltration. The long transmission distance raises questions of transmission losses which in overhead lines can be 0.5% per 100km for a 765kV line. The DA seemed to have this mind when they suggested a 20% loss of power and queried at what point the 2500MW would be measured (apparently at the DRC/Zambia delivery point per Energy Dept deputy DG Ompi Aphane). Higher voltages reduce current and therefore resistance but the upside is currently limited.