Evaluating the impact of consumer behaviour on the performance of domestic solar water heating systems in South Africa

Abstract

South Africa experienced a rapid expansion in the electric power consumer base after 1994 that was not matched by corresponding investment in the country’s generation capacity. By the dawn of 2008, the situation had reached a critical point, with regular countrywide blackouts and load shedding and is expected to persist for several years, before the proposed new base stations can come online.
Currently, 92% of the country’s electricity is generated in coal-based power stations and are responsible for the country’s heavy carbon footprint. Additionally this power must crisscross the country to distant load centres via an aging transmission infrastructure and in the process massive amounts of energy are lost particularly during peak power demand.
Electricity consumption in South African households accounts for approximately 35% of peak demand, with water heating constituting 40% of that. The country has abundant sunshine and solar water heating technology and offers one of the most viable compiementary solutions to the country’s energy and environmental crises. Moreover the location of the systems at the consumer end means that the need to upgrade the transmission infrastructure can also be differed.
Application of technology alone however, may not necessarily result in the required energy savings particularly in cases of uninformed consumer usage. In this paper the authors evaluate the impact of consumer behaviour on the performance of domestic solar water heaters in South Africa and suggest measures that could be taken to optimize this performance.