At a cross-border project between the Netherlands and Germany, people kept asking to explore the possibility of building the new power line underground. When they understood that an underground AC cable would not be possible, they focused their demands on a DC cable. A previously conducted study on the technical feasibility of undergrounding in the Netherlands came to the conclusion that no more than 20km of underground AC cables would be feasible in the Dutch system. However, since the new line is an interconnector to Germany and DC connectors are being realised elsewhere in Europe, a new study was conducted that took the DC question into account. In the end, the result was the same: an underground option in DC was not feasible mostly due to the necessity of building two converter stations and the substantial energy loss resulting from converting DC to AC (and vice versa). However, it was useful that the government commissioned a second study specifically for this case, concerning the Dutch-German interconnector.
Mr. Camiel Masselink