Why is aluminum used for the electricity cables of the national grid instead of copper?

Answer 1

Aluminum actually is used to carry electricity, but only in applications where the problems it presents can be overcome and reliability assured. Aluminum has some issues with the "joints" or connections made to it. It has a high rate of thermal expansion, so in applications where temperatures fluxuate widely and/or frequently, it may present problems. It is a pretty good conductor of electricity, and it is attractive because it is cheaper than copper, but issues with thermal expansion and also with oxidation at connections have lead to arcs and the disruption of service - and to fires.

Answer 2

Aluminum is cheaper and lighter. The downside is aluminum is not as strong as copper. In overhead power lines, aluminum is often used with an internal steel core which provides the strength (aluminum conductor, steel reinforced or ACSR).

Answer 3

Nowadays aluminum is replacing copper for use in electrical cable for two reasons:

1. Aluminium is cheaper than copper.

2. Aluminium is a good substitute for copper.

<<>>

It is not replacing copper in the smaller sizes that lesson was learned in the 70's. It is used in service entrance conductors for the reasons above. Even though the aluminum conductors has to be up sized for the same ampacity as copper it is still more economical in the larger sizes than copper.

Answer 4

Aluminium (or aluminum as it is known in America) is considerably less expensive than copper. Also, because aluminum is a different color than copper, it is sometimes useful to have a double stranded wire that has one copper and one aluminum strand, to enable you more easily to track the individual strands - my stereo cable has that design.

Answer 5

Copper is more usual for wires because it is the best conductor, except silver which is slightly better.

Aluminium can also be used. It does not conduct so well but it is a much lighter metal so it is popular for overhead power lines which use stranded cables with aluminium strands on the outside and steel strands at the centre for strength; that is called ACSR.

<><><><><>

Above IS correct- but in addition, aluminum wiring for inside buildings has been tried. Aluminum exposed to air tarnishes to aluminum oxide, which is a poor conductor. When points where aluminum wires were connected to standard switches and outlets tarnished, they get very hot when current passes thru them. This resulted in several fires. and the withdrawal of aluminum wiring for routine indoor uuse.

Additional AnswerAluminium also suffers from a problem called 'cold flow', in which the metal tends to 'flow away' from points of pressure. This causes the conductors to become loose, over time, wherever they are secured by screw terminals. This makes aluminium conductors unsuitable for use with the sort of connections used in residential wiring (e.g. screw-terminals at light switches, socket outlets, etc.).

Answer 6

For 2 reasons; alumimum is cheaper (per pound) than copper, so it's more price-competive on those multi-mile distances, plus it's lighter, which lets those expensive pylons be placed farther apart.

Answer 7

Aluminum is used instead of iron because it does not rust like iron and is very much lighter in weight.

Answer 8

Because copper is a very good conductor of energy

Though gold is better it is much more expensive

Answer 9

It's lighter and cheaper.

Answer 10

it is cheaper