Wind Power For centuries, the energy created by wind has been caught and used for milling, pumping and other things. Only in the past 50 years or so have we started to use wind energy to generate electricity on a small and large scale.

Advantages: Wind energy is there to use, it is renewable, clean and does not give off harmful gases. Our coastal regions are ideal for use of this technology.

Disadvantages: The wind doesn’t always blow, and wind generators create noise and are expensive to build, which means the electricity will be expensive.

How do we Generate Electricity from Wind Energy? The principle involved in electricity generation is very much the same as what has been used during the centuries. The only difference is the introduction of an electricity generator. The movement of air is used to propel blades. These blades then turn in the wind and along with it an axle that is attached at the centre of the blades. The axle caries over the energy to a gearbox and finally to the generator where the electricity is generated.

[source:  http://www.eskom.co.za]

Internationally, coal is currently the most widely used primary fuel, accounting for nearly 36% of the world’s electricity production.  It is likely to remain this way until at least 2020.  Coal has traditionally dominated the energy supply sector in South Africa, from as early as 1880 when coal from the Vereeniging area was supplied to the Kimberly diamond fields. Presently, about 77% of our country’s primary energy needs are provided by coal. This is unlikely to change significantly in the next decade, due to the relative lack of suitable alternatives to coal as an energy source. South Africa produces an average of 224 million tones of marketable coal annually, making it the fifth largest coal producing country in the world. 25% of our production is exported internationally, making South Africa the third largest coal exporting country. The remainder of South Africa’s coal production feeds the various local industries, with 53% used for electricity generation. The key role played by our coal reserves in the economy is illustrated by the fact that Eskom is the 7th largest electricity generator in the world, and Sasol the largest coal-to-chemicals producer. South Africa’s coal reserves are estimated at 53 billion tonnes, and with our present production rate there should be almost 200 years of coal supply left. Producing electricity from coal starts when the coal is pulverised in huge mills into a fine powder before it is blown into huge kettles, called boilers. Due to the heat in the boiler, the coal particles combust and burn to generate heat to turn water into steam. The steam from the boilers is used to turn the blades of a giant fan or propeller, called a turbine. The turbine turns a coil made of copper wire (the rotor) inside a magnet (the stator). Together they make up the generator. The generator produces an electric current, which is sent to the homes and factories of consumers via power lines.

[source:  http://www.eskom.co.za]