Enhanced energy efficiency of underground cables

Utilities can increase their energy efficiency and improve environmental quality by making a simple choice of which underground (UG) cables they employ in their transmission and distribution (T&D) systems. Underground cables, as well as many other T&D assets are most effectively evaluated on a life cycle cost basis. It can be estimated that losses associated with UG cables comprise over one third of their total life cycle cost. Dielectric losses, one of the two types of electric losses associated with UG cables, can vary widely based solely on the type of insulation used. While smaller than the inherent losses associated with the impedance of the metallic conductor, dielectric losses are present whenever the cables are energized and monetary losses can be substantial over the life of today´s modern cable designs which are projected to last a minimum of 40 years. Cables insulated with tree retardant cross linked polyethylene (TR-XLPE) insulation have dramatically lower dielectric losses than cables insulated with ethylene propylene rubber (EPR). Energy efficiency, cost savings and reduced carbon emissions can all result from using TR-XLPE for a utilities´ UG cable infrastructure.