Abstract:
up to 40% of their total energy be allotted to the heating of water. The implementation of energy efficient
or renewable energy source technologies, for the main purpose of heating water, may assist in reducing
the magnitude of the energy crisis that South Africans are facing daily. This will, in turn, reduce energy
consumption and costs, so that the energy price hikes do not affect the consumers as severely as it would
otherwise.
The purpose of this paper is to provide a survey of the most frequently used domestic water
heating technologies. The paper aims to critically analyse and summarize recent advancements made
in renewable and non-renewable water heating technologies, particularly in the South African case.
These technologies include the electric storage tank water heater, solar water heaters (passive and active
circulation), heat pump water heater, geothermal water heating, photovoltaic-thermal water heater, gasfired
tankless water heater, biomass water heater and oil-fired water heater.
Substantial research works and other academic studies focusing on efficiency improvement, optimal
design and control, were consulted and categorized in terms of contributions, focus and respective
technologies. The key findings of the review conducted on the various water heating technologies are
discussed and organized, based on the advantages, drawbacks, approximate initial investment, average
life expectancy and payback period.
The results of this survey identify gaps in existing research. The aim is to propose a new perspective
on the importance of energy efficient hybrid water heating systems and the cost savings they might offer.
