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For thousands of years people have used windmills and the energy
derived from wind to pump water and to grind corn. After a breakthrough
by scientists, wind can now also be used to generate electricity.
Wind energy, like solar energy, is a free renewable energy source
and will never run out.
The amount of energy that can be extracted from the wind depends
on its speed. The higher the wind speed, the more energy can
be harnessed to generate electricity on a large scale. However,
this requires large tracts of land to install enough wind turbines
or generators, which are also noisy.
Wind as an energy source is only practical in areas that have
strong and steady winds. South Africa has fair wind potential,
especially along the coastal areas of Western and Eastern Cape.
Currently, the Klipheuwel wind farm is operating near Cape Town
and the Darling wind farm is expected to be in operation by
early 2007. |
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Klipheuwel Wind Farm
Eskom's demonstration wind farm at Klipheuwel in the
Cape is exploring the use of wind energy for bulk electricity
generation. Of the turbines, the most basic unit is performing
the best under high wind conditions in summer, while the largest
turbine is performing the best under weak wind or winter conditions.
Overall, the total production annually has been just more than
4GWh. The Klipheuwel wind farm has a total capacity of 3.2 MW,
and is expected to generate at a load factor of between 20 and
30 percent. The wind farm consists of three units, that is two
Vestas (Danish) turbines of 660kW and 1 750kW respectively,
and a Jeumont (French) turbine of 750kW. The blade spans are
47, 66, and 48 metres respectively.
The first unit started generating on 16 August 2002 and the
last on 20 February 2003. Each wind generator has its own small
meteorological station on top of the turbine, as well as an
aircraft warning light. The wind turbines at Klipheuwel generate
at wind speeds between 11 and 50 km/hour. Full power is reached
at 50 km/hour.
Darling National Demonstration Wind Farm
In June 2000 the Minister of Minerals and Energy declared the
Darling wind farm as a National Demonstration project. This
facility will consist of four German-designed wind turbines
that will produce 1.3MW of electricity each, bringing the total
output of the wind farm to 5,2MW with an annual average output
of 13.2 GW (28% load factor). This is the 1st grid connected,
independent wind energy power-generating facility developed
in South Africa. The Darling Wind farm Company (DWP) signed
a 20 year Power Purchase Agreement (PPA) with the City of Cape
Town as well as a Power Wheeling Agreement with Eskom.
The project is being developed with financial assistance from
the Danish government through Danida, its funding agency, loan
from the Development
Bank of Southern Africa and investment by the Central
Energy Fund and the Darling Independent Power Producer.
Referred to as the National Demonstration Project, it will be
used as an example for future public-private partnerships in
the establishment of electricity generation. Historically, this
was largely the sole domain of Eskom.
The turbines are erected below Moedmaag Hill, about 12 km from
Darling along the way to Yzerfontein on the West Coast. The
structures will be 50m high and the blades will have a span
of 31m.
Approval was granted after the environmental impact assessment
as prescribed by legislation. The Department of Environmental
Affairs and Tourism (DEAT)
established the positive impacts will far outweigh any possible
negative environmental impacts.
South Africa Wind Energy Programme
The South Africa Wind Energy Programme (SAWEP) originated from
the declaration by the Minister of Minerals and Energy in June
2000 of the Darling National Demonstration Wind Farm as a National
Demonstration Project and her request for international assistance.
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