

Photovoltaic modules are gaining popularity in South Africa,
with around 200 000 households making use of this technology
(e.g. lighting, television, telecommunications). At present,
the solar modules are expensive, although their cost has been
steadily declining. The major drawback for solar generated
electricity is that it is difficult to store. For off-grid
systems, current storage technologies require significant
running costs (due to their limited life). However, new technologies
such as super capacitors, flywheels and fuel cells, as well
as improved chemical batteries, are expected to reduce storage
costs significantly. Currently grid-connected applications
are the main international market for PV technology. In this
case, the ‘grid-system’ can be used as storage
along with distributed storage options and pumped storage
systems.
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Solar thermal electric technologies use the sun’s heat
to drive either conventional steam turbine drive power plants,
or to power more unusual engines such as the Stirling engine.
Solar thermal electrics have an advantage in that single plants
can be built on a multi-megawatt to gigawatt scale. There
is also some potential for energy storage in thermal energy
stores (e.g. molten salt). This allows some solar thermal
plants to run well into the evening, or even 24 hours a day.
Gas hybridisation options are also practical.

Solar water heaters, process heaters, space heating systems
and even solar cookers are all currently used in South Africa.
The water heater market in particular shows significant signs
of maturity and growth potential. However, as a country, South
Africa is behind best practice norms with regards to utilising
this resource.
According to the Australian Greenhouse Office website
"For most households, hot water is the largest energy
cost and cause of greenhouse gas emissions."
Solar and heat pump water heaters use much less energy and
therefore produce significantly less greenhouse gas emissions
than electric conventional water heaters. |