Document Type

Closed Project

Publication Date

Spring 2012


Tugrul Daim

Course Title

Energy Technology Innovations

Course Number

ETM 510/610


Dwellings -- Energy consumption -- South Africa, Solar water heaters -- Consumer attitudes, Hierarchical Decision Model


In recent years there has been a major drive for the adoption of energy efficient devices in the residential sector of South Africa. The introduction by the Utility (Eskom) of incentives for solar water heaters and heat pump water heaters, as well as the Residential Mass Rollout Program has tried to encourage this adoption. Since this is a decision by the consumer on which of the available technologies to choose from, a Hierarchical Decision Model (HDM) was created to try understand this decision. A survey was sent out to eleven consumers in South Africa and a pairwise comparison was used to determine the importance among the criteria and sub criteria that are part of the purchasing decision. It was determine that the criteria with the highest importance were Performance and Economic , while the lowest importance was Support and Service. The highest relative importance of the sub criteria to the goal was for Environmental Performance and the lowest was for Upgradability and Utility Incentives. The outcome of the model ranked the geyser controller the highest when incentives were not taken into account, and the heat pump water heater the highest when current incentives were included. The lowest ranked in both scenarios was the gas stove hob. This model can be used as an effective way of understanding consumers purchasing decisions as well as for ranking new energy efficient technologies against existing technologies before they enter the market.


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