SA Affordable Housing September - October 2019 // ISSUE: 78 | Page 19

FEATURE
SOLAR POWER
Housing finance must
embrace solar power
Solar installations can be paid off within five to seven years producing long term savings.
The use of solar thermal (ST) and solar photovoltaic (PV) systems
in housing must increase if the demand on energy is to be
managed in South Africa’s growing urban environment.
By the South African National Energy Development Institute
T
hese systems are available and coming down in costs
and payback period (5-7 years), therefore financing of
affordable housing must stress the inclusion of these
systems at construction stage, rather than as an add-on.
This is the opinion of Barry Bredenkamp, General Manager
Energy Efficiency for the South African National Energy
Development Institute (SANEDI), who started work in this
area in 1996, when South Africa had amongst the cheapest
electricity tariffs in the world and surplus electricity
generating capacity.
At the affordable housing level, there must be the
inclusion of solar thermal systems to provide hot water and
the addition of PV systems to generate electricity for the
householders. These systems could run independently of
each other or work in tandem.
There is a lack of understanding as to the difference
between the two systems and how the technological
advances, even over the last few years, have reduced the
costs of solar energy.
“What is evident is that the majority of the residential
property market – 58% at the end of 2017 – includes
homes valued at less than R600 000. About a third of the
total residential property market is estimated to have been
fully subsidised by the government. Housing affordability
also remains a critical challenge. In 2018, the cheapest
newly built house was estimated at R352 500,” says
Bredenkamp.
www.saaffordablehousing.co.za
RELIABLE HISTORY OF SOLAR THERMAL
SYSTEMS
Solar thermal collectors use the same solar energy that
photovoltaic panels do, but they generate heat instead of
electrical power. A considerable share (40-50%) of electricity
used in the residential sector is for hot water preparation.
Solar thermal water heaters in this sector can reduce the
electricity demand and thus lower the environmental effects,
like CO 2 emissions, caused by fossil fuel power plants.
“In comparison to other regions of the world, the use of
solar thermal energy is still very low in African countries,
even though the resource – the availability of solar radiation
– is one of the highest worldwide and available in all African
countries”, Bredenkamp continues.
These ST systems are well known in the market. The
majority of the installed systems are thermosyphon systems
that, in the South African low-cost housing sector, are
relatively small in scale. They also do not need electricity
for a pump or an electronic control mechanism, enabling an
installation in regions without access to the electricity grid.
Typically, solar panels work by transferring heat from the
collector to the tank through a separate circuit and a heat
exchanger. Heat collected by the panel heats up water that
flows through a circuit of pipes into a copper coil inside a hot
water tank. The heat is then passed into the hot water tank and
the cooled water returns to the collector to pick up more heat.
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