Design of Cost-effective Energy Supply Systems for domestic Households in Developing Countries -- Pledge for utilising Thermal Energy to Electricity Conversion Systems

Abstract

Abstract A medium scale household in South Africa consumes about 1000 kWh on average. This amounts to about 3300 ZAR per month is spent on energy supply using grid electricity. Grid electricity in South Africa is supplied by a huge governmental organisation at about R3..00 per kWhr, including taxes. Statistical analyses indicate that the current increase of the cost of grid electricity in South Africa is about 60% per annum. Solar energy irradiation levels in South Africa are about 850 W/m2 on average in summer. This study shows that by utilising a hybrid combination of renewable energies, such as combining PV supply with solar thermal energy absorbers, converting thermal energy to electricity, and also using petroleum gas and wind turbine energy supply systems as supplements, could reduce the current cost of electricity per household in South Africa to about half of the national grid supply prize, i.e about R1.50 per kWh. The study also shows that water provides as a most viable medium to store energy overnight, instead of using expensive battery technology to perform such functions. Our research also show that Photo-Voltaic (PV) only technology can offer as viable second alternative, provided a large initial capital outlay can be made. The cost of this type of electricity utilised, capitalized over 20 years, is around 2.80 ZAR.