Electricity Generation: Superconductors:
Better production and transmission of electricity.

Electricity is produced at power stations and sent along high voltage transmission lines (see figure above).  Energy losses always occur as one form of energy (such as the chemical energy in natural gas) is converted into electrical energy. In fact, energy losses occur during each stage of the electricity production process. As a result, only about 30 to 42 per cent of the original energy is converted into electricity.

When electrical energy is sent through power lines, as much as 20 per cent of this energy is lost in the form of heat. This energy loss occurs when the electric cur­rent encounters resistance in the copper wire. As the electric current passes through the power lines, some of the electrons collide with other electrons, dissipating their energy in the form of heat.

To view a diagram of the coal to electricity process:
http://www.macgen.com.au/

However scientists are on the brink of making discoveries which could lead to incredible savings in energy. Their research is focusing on “superconductivity”. The superconductivity process involves a remarkable transition, which occurs in many metals when they are cooled to temperatures within 20 degrees of “absolute zero”, or, as scientists prefer to designate it, 20° Kelvin (20K). Absolute zero is the equivalent of -273°C and it is the coldest temperature conceivable.

As the metals approach absolute zero temperature, they suddenly lose all their electrical resistance and become “superconductors”. This enables them to carry electric currents without the loss of any energy and in some cases to generate immensely powerful mag­netic fields. This is because in super­conductors, the electrons do not col­lide but are bound into pairs and move in step with each other.

The discovery of superconductors was made as far back as 1911. However within the last few years, superconducting materials have been discovered (special ceramics) which will operate well above 20K. There have been recent claims of super­conducting materials which operate close to room temperature. It is cheaper and more feasi­ble to use a superconducting material if the operating temperature can be raised to room temperature.

Most scientists believe the successful development of superconductors could lead to huge savings in energy, as well as highly efficient electric generators and motors; trains that speed across the countryside at hundreds of kilometres per hour on a cushion of magnetism; practical electric cars; more powerful computers of a more compact size; safer reactors operating on nuclear fusion (rather than nuclear fission); and a host of other rewards still undreamed of. Scientists are already working on the idea of using superconductors for electric power production. If power station genera­tors had super­conducting electromagnets, the out­put could be doubled. This would be a big savings to Western Australian electricity businesses and consequently to their customers. In theory, all of a large city's electrical energy needs could be supplied through a handful of underground cables.

For more information about superconductors, go to:
http://science.howstuffworks.com/question610.htm

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