Final EIAR - Aurecon AME Environmental | Environmental Projects

Proposed Wind and Solar (Photovoltaic) Energy Facilities on Kangnas Farm near Springbok in the Northern Cape: Final EIR 32
3.2 DESCRIPTION OF THE PROPOSED ACTIVITIES
3.2.1 Wind Energy Facility project
The proposed wind energy facility would consist out of four phases of 140 MW each, the
turbine sizes would range between 1.5 – 4 MW which means each 140 MW phase may consist
of between 94 (using 1.5 MW machines) to 35 turbines using 4 MW machines). The combined
four phases would have a maximum total installed capacity of 560 MW. The size of the turbines
would be selected by the developer in a tender process nearing the point when this project is
nearing the DoE’s procurement programme, the final turbine would be selected based on fit for
site technology, cost of technology available within required timelines, local content achieved by
respective turbine suppliers, turbine dimensions and numbers approved within this
environmental study, etc.
A wind turbine is a rotary device that extracts energy from the wind. If the mechanical energy is
used directly by machinery, such as for pumping water, cutting lumber or grinding stones, the
machine is called a windmill. If the mechanical energy is instead converted to electricity, the
machine is called a wind turbine. Figure 3.1 shows a wind energy facility in Texas, United
States of America.
3.2.2 Components of a wind turbine
Wind turbines can rotate about either a horizontal or a vertical axis. Turbines used in wind farms
(see Figure 3.1) for commercial production of electricity are usually horizontal axis, threebladed
and pointed into the wind by computer-controlled motors, as is proposed for this project.
These have high tip speeds of over 320 km/hour, high efficiency, and low torque ripple, which
contribute to good reliability.
The main components a wind turbine is made up are listed and described below (see Figure
3.2):
• Rotor and blades;
• Nacelle;
• Generator;
• Tower; and
• Foundation.
3.2.2.1 Rotor and blades
The rotor has three blades that rotate at a constant speed, approximately 6-15 revolutions per
minute (rpm) in the case of the turbines being considered at Springbok. The blades are usually
coloured light grey and, in the case of the proposed project, would be approximately 40 – 60 m
long (80 – 120 m rotor diameter).
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or adaptation, in whole or in part, may be made.
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