| Abstract |
Low to medium temperature geothermal resources widely exists in South Africa with a great potential for exploitation and utilization to generate electricity, but they remain untapped. On global scale, such resources have become one of major renewable energy resources for decades, but in South African they have been overshadowed by the usage of coal as a means of primary energy generation. However, due to energy crisis, the state has begun considering the potential of renewable resources as alternative and a possible long term energy supply. Geothermal energy is excluded partly due to convenient technology barrier and also lack of government support. To tackle this problem, we investigated the potential of geothermal energy using variety of available geologic data such as heat flow measurements, hot springs, and petroleum & mining exploration boreholes. Data shows that geothermal potential areas with good heat flow include the Namaquland, south and west of Upington; northern part of Kwazulu-Natal; thermal springs at Tshipise, Brandvlei, and Siloam hot spring in the Limpopo Province shown in figures on text. On tapping these untapped heat resources, a thermoelectric generator (TEG) is proposed for geothermal power generation in this study. TEG technology is capable of converting heats into electricity directly with less or no mechanical work involved, and at a cheaper cost as compared to the traditional high-cost technologies, such as Steam Rankine Cycle (SRC), Organic Rankine Cycle (ORC) technology and etc. Moreover, economic appraisal of a Binary system proves not to be economic friendly than a TEG system because it cost high, making the TEG a better viable energy option for South Africa. With the generation of electric energy using TEG, not only does the waste heat provide heat source but also reduce carbon emission while improving the efficiency of TE based systems. Finally, after considering the nature of the resources in South Africa and the cost of the available heat recovery systems, we laid down a proposal for using Thermoelectric Generators (TEGs) as the suitable and convenient technology. |