What are superconductor’s roles for lossless power distribution?
All the power losses that occurs in an electrical system boils down to the fact that all of the components needed to transmit electrical power has resistance. Power losses is dissipated in the form of heat in the electrical system happens because there is an opposition to the flow of current called resistance.
Given this fact, we may wonder what if resistance does not exist in any electrical components. By then we can assume that our system would inevitably be a 100 per cent efficient one. Utilities would no longer worry about technical losses in its system.
Fortunately, we now have that technology readily available for use in the form of Superconductors. Superconductors are defined as materials that have no resistance to the flow of electricity and are one of the last great frontiers of scientific discovery.
Not only have the limits of superconductivity not yet been reached, but the theories that explain superconductor behavior seem to be constantly under review. In 1911 superconductivity was first observed in mercury by Dutch physicist Heike Kamerlingh Onnes of Leiden University. When he cooled it to the temperature of liquid helium, 4 degrees Kelvin (-452F, -269C), its resistance suddenly disappeared. The Kelvin scale represents an "absolute" scale of temperature.
Thus, it was necessary for Onnes to come within 4 degrees of the coldest temperature that is theoretically attainable to witness the phenomenon of superconductivity. Later, in 1913, he won a Nobel Prize in physics for his research in this area.
Superconductivity, on the other hand, is a phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occurring in certain materials when cooled below a characteristic critical temperature.
The electrical resistivity of a metallic conductor decreases gradually as temperature is lowered. In ordinary conductors, such as copper or silver, this decrease is limited by impurities and other defects. Even near absolute zero, a real sample of a normal conductor shows some resistance.
In a superconductor, the resistance drops abruptly to zero when the material is cooled below its critical temperature. An electric current flowing in a loop of superconducting wire can persist indefinitely with no power source.
Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical phenomenon. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor as it transitions into the superconducting state. The occurrence of the Meissner effect indicates that superconductivity cannot be understood simply as the idealization of perfect conductivity in classical physics.
Sources: wikipedia, www.superconductors.org
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