The use of small scale hydroelectric power in South Africa, hydro and economic potential for rural electrification.
Small hydro generation refers to generating capacity of less than 10 MW with the most common being Run-of-River. In South Africa, the level of rural electrification is approximately 50 percent with most of the energy needs being met with biomass fuels. The purpose of this study was to investigate the hydropotential regions that were identified by Eskom and the Department of Minerals and Energy in 2002 and determine sites for small scale development for rural electrification purposes. Technical and feasible analyses were carried out in order to assess the applicability of this kind of energy generating system. The aim of this study was to consider the Free Basic Electrification policy and Solar Home Systems to assess the electrical demand of rural households and possible funding transfer scheme respectively. Furthermore, to formulate an appropriate methodology that can be used given the available data and resources currently available in South Africa. In total, six sites were identified and analysed in this paper, namely: (1) Berg River at gauge G1H013, (2) Mzimvubu River at gauge T3H008, (3) Orange River at gauge D1H003, (4) Mlambonja River at gauge V1H041, (5) Thukela River at gauge V1H002 and (6) Mkomazi River at gauge U1H005 which are in the Eastern Cape, Western Cape and KwaZulu-Natal Provinces. Flow gauge data were analysed in order to develop monthly mean Flow Duration Curves which were used to determine the design flow, power generation (through Power Duration Curve construction) and renewable energy potentially produced from each scheme. Costing functions were utilised in order to determine the initial capital cost of the system which was used to assess the project’s feasibility. In order to predict potential power output of the schemes, the streamflow and hydraulic head of the six rivers were assessed. The potential renewable energy production ranged from about 240 to 6060 MWh/year. Through this energy production, it was found between 165 and 10100 houses could be electrified depending on the electrical allowance provided. This significantly exceeds existing housing numbers. Costing bands ranged from 3 – 7 R/kWh which was high but within reason based on the community income and the transfer of the Solar Home Systems pricing policy. The results of this study provide a good foundation for future work in the estimation of hydropower potential in South Africa and will hopefully be a stepping stone to better estimation of both technical and exploitable hydropower potential for South Africa.