This study provides a comparison of photovoltaic- (PV) and solar thermal- (solar water heater, SWH) hot water systems for residential use in South Africa. The study was carried out as a financial feasibility analysis using the performance and cost data recorded from the 1.56 kW(p) PV and 2.4 m(2) SWH hot water systems installed at 2 separate houses on Mariendahl Farm, Stellenbosch, South Africa. Performance data recorded from these systems, from 1 May 2018 to 30 April 2019, was also used to investigate the financial feasibility of another inexpensive PV water heating system locally available on the South African market. The study compares the performance and financial feasibility of the 4 different alternatives of solar water heating systems over a 25-year period. Financial factors including; capital costs, total savings, net present value (NPV), internal rate of return (IRR) and levelized cost of heat (LCOH) was determined and compared for all of the solar solutions. The SWH and PV hot water systems produced a total of 2 219 kWh(th) and 1 403 kWh(th), respectively, indicating a 45% difference in the annual thermal energy yield. The SWH and PV hot water systems produced annual heat gains of 925 kWh(th)/m(2) and 140 kWh(th)/m(2) over the same period, respectively. When comparing the financial outcomes of the study, it can be seen that the 2.4m(2) SWH system provides the largest benefits from a cost perspective, with a payback period of 6 years and a LCOH of 0.04 USD/kWh(th) over the 25-year period.
