Underground Cables at Extra High Voltage Levels

Europacable is the European Confederation of Associations of Manufacturers of Insulated Wires and Cables. Europacable, and its member companies in the European cable industry, have spent 30 years investing in innovative technology for underground cabling that overcomes the limitations of overhead lines in certain circumstances, and today, cable manufacturers are able to provide innovative and customised solutions for the modern power transmission industry.

Crosslinked polyethylene (XLPE) cables have been in commercial use at high voltage (HV) levels (i.e. 220-275kV) in Europe for over 25 years and, although XLPE cable systems at extra high voltage (EHV) levels (i.e. above 380kV) were only introduced in the early 1990s, they have become the globally preferred insulation for underground power cables.

Around 2,000km of underground EHV cables exist in Europe and over 4,000km worldwide today. Although most of these have been laid either in urban areas, to support major infrastructure projects, under waterways or to link power stations to the transmission network, over the last 40 years, EHV underground cables (UGCs) have also been laid in rural areas across Europe, principally in areas of outstanding natural beauty or where visual amenity supports an underground approach and planning consent for an overhead line (OHL) was unlikely to be granted within an acceptable timeframe.

Since their introduction in Europe in 1997, 400kV XLPE systems have had an excellent service record and have been installed in/around Berlin, Copenhagen, London, Madrid, Milan, Rotterdam, Turin and Vienna and in rural areas of Denmark and Italy. There has also been a significant expansion of EHV cable systems elsewhere in the world including the Middle East, China, Japan, South Korea and the USA. At HV levels, XLPE cable systems have been installed since the 1980s in various locations in Europe such as Barcelona, Dublin, Lisbon, Paris and Stockholm and many other parts of the world.