Aluminum wire is used as electrical conductors on electric utility transmission and distribution systems. The overhead wires spanning utility poles are made of aluminum and do not have insulation around them.

Aluminum has two advantages over copper as a conductor for utility lines:

• It is lightweight and economical. The light weight permits larger spans between poles.
  
• And because aluminum costs less than copper, it helps utilities keep costs down.

Most electrical codes do not permit aluminum wiring in residential buildings. Aluminum can be used in many commercial and industrial buildings provided it is installed and maintained under strict rules.