This paper focuses on the energy economics and
environmental impacts of solar water heaters
(SWH) in the Gauteng Province and compares the
results with other technology options for residential
water heating with regard to the different income
groups. The critical energy situation in South Africa
and the highly coal dependent energy generation
demonstrates the need to shift to a more sustainable
way of living. The residential sector proves to be an
optimal starting point to implement new technologies,
especially for water heating.
The residential hot water demand calculation
shows that the annual demand in Gauteng is about
188 million cubic meters. In order to satisfy this
demand, different technologies are investigated in
this paper, where SWHs lie in focus.
Due to the vast income inequality in Gauteng,
and also in South Africa, it is obvious that there cannot
be one single optimal solution suitable to all
households. Therefore, this paper focuses on the
differentiation of the residential sector into income
groups to show the divergence in warm water
demand and the applicability of alternative technologies.
In order to analyse appropriate solutions
for all income groups, low-cost alternatives are also
analysed. The economic analysis shows that
although SWHs have higher investment costs than
conventional technologies, the payback periods are
relatively short (between 3 and 4 years) for high
and mid income groups. The payback periods will
be even shorter when the planned electricity price
tariff increase comes into effect. Furthermore, SWH
utilisation has the additional effect of reducing the
overall electricity demand up to 70% and greenhouse
gas emissions significantly. In addition, SWHs
are the most cost-effective water heating technology
to reduce greenhouse gas emissions for mid and
high income groups with negative abatement costs.
It is concluded that the SWHs are the most suitable
option to decrease fossil energy consumption
and reduce the household’s expenditure for energy
services, especially for mid and high income groups.
For lower income groups the utilisation of solar
energy can increase the access to energy services
and living quality and, therewith, lessen the financial
burden to meet their energy needs.