Underground gas insulated cables show promise

Underground gas insulated transmission lines hold out the prospect of carrying up to 3000 MW of electrical power over long distances (one hundred kilometres or even more) at less than ten times the cost of a conventional overhead line. This at first sight may seem too high a price to pay, but considering the growing public opinion against the erection of new overhead lines in urban areas and nature reserves for example, the extra cost could well be considered justifiable by many electricity distribution authorities. This article looks briefly into the basic technology and outlines a feasibility study that is currently underway.