What are the requirements for linking an underground section to an overground section? How much land is required?

The size of the transition/sealing end compound would depend to some extent on the number of cables, but if two circuits of three cables are used, the analogy is more like a “tennis court”; if four cables are used the analogy is more like a “football field”. If the transition compound is placed in a woodland area, it can be easily camouflaged from view. In Denmark, for example, the compounds had to be camouflaged through tree and shrub planting. Today, the transition of a 275 kV line can be housed directly on the last tower, and it may be that, in the near future, the same transition will be available at 400 kV. In a recent CIGRE paper into 400kV cables in rural areas, the six transition compounds were approximately 50x80 metres. These were designed to accommodate two double cable circuits.