Gold and silver are considered the best conductors offering the least resistance, but due to their high price cannot be used for mass deployment. Copper and aluminium are the next best alternatives, each with pros and cons. Despite its drawbacks, the advantages aluminium offers over copper are increasing its popularity for use in domestic electric wiring, with the National Electric Code specifications approving its use in alloy form.
The primary reason for using aluminium power cables is significantly reduced costs. Copper prices spiked in the mid- 1960s and have been rising ever since, making copper wiring quite expensive. Aluminium is much cheaper and offers similar performance. Although when used in its pure form there is a reduction in performance in a few areas, alloys have been developed to remedy this issue.
Copper wiring can be three times heavier than identical aluminium wiring. Aluminium's reduced weight means less strain on supporting equipment for suspended cables, lower transportation costs and hassles and more efficient handling during installation.
Aluminium is also more flexible than copper and more suitable for use in cables exposed to frequent bending and twisting. Aluminium's tendency to break is much lower, increasing the cable's reliability and reducing the chance of power disruptions due to cable damage by bending.
Reduced Corona Effect
Corona discharge or corona effect is the formation of ions around a conductor which results in electrical discharge of the current flowing through it at high voltage, leading to power wastage. Copper cables are prone to a higher level of corona discharge.