Electricity systems and sources

Underground cables

Electricity can be transported either by overhead lines or underground cables. Like overhead lines, underground cables can be either AC or DC and there are various reasons why underground cables may be used rather than overhead lines.

Underground cables produce EMFs in the same way as an overhead line, but the electric fields from underground cables are contained within the cable's protective insulation and sheath, so there are no external electric fields. The magnetic field can pass through the sheath and the ground so there is still an external magnetic field associated with buried cables. As with overhead lines, underground cables will always produce magnetic fields that comply with the UK exposure guidelines. 

Underground cables can be either used for transmission or distribution.

Find out more about transmission cables

Find out more about distribution cables