Most of the electrical power generated at the power plants is transmitted and distributed through overhead lines. The power transmission and distribution through overhead lines employs conductors with appropriate spacing between them supported on towers or poles.

The spacing is provided to avoid electrical discharge between conductors by increasing the insulation. Compare to underground power transmission and distribution lines, overhead lines are much cheaper.

For transmitting power over long distances at higher voltages, overhead lines are the best choice. For the same power transmission, insulation cost and size of conductor required for underground cables is more. The erection cost is much lesser and the maintenance is convenient for overhead lines.