Comparison of Photovoltaic- and Solar Thermal Hot Water Systems in the South African Context
Abstract
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 technical performance and lifetime costs are evaluated and compared. A feasibility analysis is carried out using the data gathered from PV and SWH hot water systems at Mariendahl Farm, Stellenbosch, South Africa and measured data from installations provided by a South African PV hot water system manufacturer. The feasibility of the technologies are compared taking into account lifespan of the installations, specific solar yield (kWh/m2), efficiency (%) and thermal energy (kWhth), capital costs, operation and maintenance (O&M) costs and electricity costs for investigating the annual savings, internal rate of return (IRR) and payback periods of systems over their respective lifespan. The study develops levelised cost of heat (LCOH) for both technology types and identifies challenges to the uptake of PV water heating and SWH systems in the country.