Aluminium conducts electricity!

Whether you need ice cubes, a hot pizza, a cold beer, clean washing or sufficient light: you cannot have any of them without electricity in the home. Not to mention industry, which would not be possible in today's form without electricity. Aluminium overhead lines make the efficient transport of electricity possible to our homes and to our factories over large distances.

Electrical current needs a metallic conductor to flow. Today, this is usually aluminium or an aluminium alloy such as the "Aldrey" alloy (AlMgSi). The conductor cables of aluminium have a steel wire core to ensure mechanical stability. The diameter of the overhead lines is determined by the expected current intensity to ensure that they do not overheat. For lines to carry 380 volts, which are required for household power supplies, cables are used with e.g. a steel cross-section of 85 mm2 and an aluminium cross-section of 680 mm2. The cable thus as a diameter of around 35 mm and can withstand a long-term load of around 1,100 amps. The cable temperature under normal load is around 40°C. With a distance between pylons of 330 metres, a cable sag results, when the required tension of the cables is taken into account, of around 12.5 metres. However, this varies depending on the temperature and on the season: in a hot summer, the cable can actually be up to 1.8 metres lower.

Air serves as the insulator for the electrical lines; mechanical insulators, e.g. of plastic, glass or porcelain, are only used at the positions where the lines are secured e.g. to the pylons.

In Germany, all high-voltage networks are connected to a national grid whose total length amounts to around 1.5 million kilometres. The German grid is in turn connected to the western European grid, which makes it possible to exchange power between countries. Storage power plants in Switzerland and Austria, for example, supply electricity to Germany at peak times, while Germany passes on basic load power from fossil fuel power stations.

Aluminium's capability of conducting electrical current has helped us enjoy considerable comfort.

Overview