The Darling Wind Farm is intended to be a learning platform for the development of the wind energy industry in the country, by providing a financial, contractual, technical and operational framework for further independent power producer projects.
Further, the project is in line with the Government’s vision in respect of climate change and pollution mitigation, efforts to create a new industry and help the local population to benefit economically.
Construction on the project started in September 2007 and the first wind-generated energy was produced in May 2008.
In one year the 4 wind turbines installed (each 1.3MW) produce 8.6 Giga Watt hours or the equivalent of the yearly consumption of some 700 average South African households.
The turbines rise 50 meters above the ground, (equivalent to a 17-storey building) where the three rotor blades and the nacelle, housing the generator and the gearbox, are located. Their combined weight is 62 tons.
The turbines start producing power at a wind speed of 8km/h. They reach their full potential at 54 km/h wind speed. The blades rotate slowly at a constant speed of 32 revolutions per minute regardless of the wind speed. The length of the blades is 32 meters, just slightly more than the length of a tennis court.
A computer monitors the turbines’ condition permanently with over 100 sensors, ranging from wind speed and direction, turbine orientation, temperature, vibrations, the electricity produced etc. in order to optimize the production and efficiency at any time.
Should wind speeds exceed 97km/h, the control system will close the system down and initiate braking to stop the blades from turning.
Wireless technology allows operation, of the Wind Farm to be remotely controlled from anywhere over the internet, allowing for the monitoring of possible alarms, support from the manufacturer (Germany) and swift response action 24hours a day.
All turbines are connected to small transformer houses built next to their foundations where the current is transformed from 690V to 11000V, In turn each transformer is connected in series to the main transformer or substation built at the bottom of the hill where the current is transformed from 11 000V to 66 000V. The substation is linked to the national grid and feeds electricity into a 66 000Volt high voltage line under the control of Eskom.
The next stage of the project will consist of 10 wind generators.
