The use of benchmarking techniques for evaluating township reticulation systems

At the present time one of the major thrusts in South Africa is the provision of electricity to the large majority of the population who are still living without a supply. The aim of this drive towards electricity for all is to connect about half a million consumers per year for the next 10 years. Because of the scale of these plans the costs involved are extremely high and numerous alternative reticulation systems are being investigated in attempts to reduce these costs. However, the assessment of all these alternatives is in itself a problem. This paper proposes a method of adopting the concept of “benchmarking” used in the computer industry to enable a quick comparison of alternative reticulation practices to be made. It involves the use of a set of standardised maps and specialised computer CAD based software. The system enables a particular distribution system to be matched with the appropriate map topography and consumer loading patterns. A costing spreadsheet is used to evaluate the scheme. The spreadsheet can either be directly utilised as supplied or easily customised to suit differing costing practices. It is shown that by using the proposed “benchmarking” procedure systems that differ in respect to the type of cabling used, the value of the medium voltage supply, the sizes of transformers, the number of phases and many other features can be evaluated for different terrains, load patterns and population densities. From the example given for two systems in present use a table is presented that shows how the costs vary for different situations