Construction World August 2015

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CONSTRUCTION WORLD AUGUST 2015
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COMMENT
EDITOR
Wilhelm du Plessis
ADVERTISING MANAGER
Erna Oosthuizen
LAYOUT & DESIGN
Lesley Testa
CIRCULATION
Karen Smith
TOTAL CIRCULATION:
(First Quarter ’15)
4 698
PUBLISHER
Karen Grant
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Tandym Cape
Wind energy now accounts for about half of all
renewable energy generated in South Africa:
740 MW of electricity is contributed to the
grid – out of the 45 000 MW of installed power
in South Africa. According to Johan van den
Berg, CEO of the SA Wind Energy Association,
the entire fleet of wind turbines is currently at
a capacity of 70% – this is because wind does
not blow consistently.
If one looks at our wind energy in context,
South Africa currently produces around 2,5% of
what Denmark produces (wind energy). Van den
Berg is the first to admit that there is huge room
for improvement – especially given the optimal
South African winds that are still unharvested.
South Africa’s winds
South Africa’s size counts in its favour as far as
harvesting wind energy is concerned. A project
that mapped winds has found that South Africa
has very good winds by international standards.
In fact, it found a 20 000 MW wind industry
quite possible. According to Van den Berg, an
In a world where regular load
shedding has become a reality,
industry and normal South
African citizens have looked to
renewable energy sources as a way
to become independent of Eskom
and its dependence on electricity
generated from fossil fuel and
nuclear energy.
industry of this size equates to around 7 000
towers and turbines.
As far as the wind situation goes: the
mentioned study showed a U-shape – starting
about 400 km north and west of Cape Town,
running down to the coastline and to the edge
of the former Transkei. This means that areas
inland – such as the central Karoo, are also
good wind areas.
Advantages of wind energy
Apart from the fact that it is renewable, the
biggest advantage is the relatively short up-time
of wind power when compared to fossil and
nuclear power generation. Van den Berg
says that a wind farm can reach the bidding
process within four years. He indicates that
this has already taken place and various wind
farms are at the execution stage. From bidding,
the next phase, according to Van den Berg is
‘financial closure’ during which construction
begins. Depending on the size of the wind
farm, construction can take between 12 and
14 months (for a small wind farm), while larger
farms take longer.
In South Africa, by international standards,
extremely large wind farms are being built – up
to 60 large turbines (130 MWand 140 MW). Even
though the construction of such farms may
take up to 18 months, it is still much faster than
conventional power plants that may take up to
15 years to complete.
Wilhelm du Plessis
Editor
@ConstWorldSA