SuedLink is evolving in major steps this year. The DC line – realised jointly by the two TSCNET shareholders TenneT, the Dutch-German transmission system operator (TSO), and TransnetBW, the TSO from southwest Germany – is the largest and probably most important single project of the energy transition in Germany. With around 700 kilometres of underground cable to be laid and an investment of around €10bn, SuedLink will connect the windy regions of northern Germany with the centres of consumption in the industrially highly developed south and west. In February 2020, the Federal Network Agency (Bundesnetzagentur) initiated the plan approval procedure for the first SuedLink sections, in May the orders for the regional planning offices were placed and now TenneT and TransnetBW have awarded the contracts for the plastic-insulated 525kV underground cables – in parallel with the ongoing approval procedures.
NKT and Prysmian PowerLink have eventually been selected as providers for the SuedLink cables, with a total order value of approximately €2bn. The contract comprises design, manufacture, supply, laying of the underground cables, further installation work, and the final high-voltage testing of the cable system. Both companies have demonstrated their expertise in numerous international connection projects on and offshore, and both have proven the quality of their cables in extensive prequalification tests with several cable manufacturers in a multi-year test phase. They were also commissioned for the German affiliate project, SuedostLink, by the two TSOs 50Hertz and TenneT.
TenneT and TransnetBW chose plastic-insulated underground DC cables with a voltage level of 525kV because they transmit more power compared to a 320kV solution and only require half as many cables. Less transmission loss and less civil engineering work translate into both, financial benefits for the TSOs and minimal environmental impact. TenneT Managing Director Tim Meyerjürgens comments: “In the future, SuedLink will form the backbone of the energy transition in Germany. With the commissioning of the DC ground cables, we are now moving from the planning stage to the realisation of this important power link.” Dr. Werner Götz, Chairman of the TransnetBW Executive Board, adds: “We are very happy to be able to apply this innovative and environmentally benign technology for SuedLink.”
TenneT and TransnetBW awarded the contracts for the 525kV DC underground cables for the SuedLink power highway (picture: TenneT)