Some people ask me why Van uses silver for electrodes in the Line. So , here it is.
Copper has a high conductivity. Silver is more conductive, but due to cost it is not practical in most cases. However, it is used in specialized equipment, such as satellites, and as a thin plating to mitigate skin effect losses at high frequencies. Because of its ease of connection by soldering or clamping, copper is still the most common choice for most light-gauge wires.
Aluminum wire has been used in building wiring for its lower cost. By weight, aluminum has higher conductivity than copper, but it has properties that cause problems when used for building wiring. It forms a a resistive oxide within connections, causing terminals of wiring devices to heat. Aluminum can "creep", slowly deforming under load, eventually causing device connections to loosen, and also has a different coefficient of thermal expansion compared to the materials used for connections. This accelerates the loosening of connections. These effects can be avoided by using wiring devices approved for use with aluminum.
Aluminum wires used for low voltage distribution, such as buried cables and service drops, require use of compatible connectors and installation methods to prevent heating at joints. Aluminum is also the most common metal used in high-voltage transmission lines, in combination with steel as structural reinforcement.
Anodized aluminum surfaces are not conductive. This affects the design of electrical enclosures that require the enclosure to be electrically connected.
Source :
Wikipedia
