Siemens is to supply eight converter transformers for the Nemo Link project, a high-voltage direct current (HVDC) transmission system connecting Belgium and Great Britain. The customer is Nemo Link, a joint venture between National Grid Nemo Link Ltd, a subsidiary company of the UK’s National Grid Plc, and the Belgian Elia Group. The HVDC link will deliver a transmission capacity of 1,000 mw that is enough to power 500,000 households, a Siemens release said. The value of the transformer order amounts to over 32 million euros. Commercial operation of the link is scheduled to commence in 2019.
The scope of supply comprises eight transformers, each with a power rating of 365 MVA. Fully assembled and installed, each of these transformers weighs some 448 tonnes, and measures 17.0m x 4.1m x 10.6m without the cooling systems. The rated voltage of these large transformers is 400/470/20.2 kV with a transmission voltage of ±400 kV DC via the HVDC system. In transport, each transformer weighs 313 tonnes. The transformers will first be transported ex-works by heavy-lift trailer from the Nuremberg transformer plant to Nuremberg's inland harbor. From there, an inland waterway barge will carry the transformers through the Europa Canal system to Antwerp and Bruges in Belgium. Four of the power transformers will be brought by heavy-lift transport to the project construction site in Herdersburg, near Bruges. The other four transformers will be loaded onto a roll-on roll-off (RORO) vessel, shipped to Ramsgate in England and then onward transported by heavy-lift trailer to the project site in Richborough, 20 kilometers west of Canterbury.
In June 2015, Siemens had already been awarded the order for turnkey erection of the link’s two converter stations using HVDC Plus technology with a transmission voltage of ±400kV DC, and also concluded a service and maintenance agreement for five years. Nemo Link has been designated as one of the European Commission's projects of common interest to help create an integrated European Union energy market. The project will enhance energy security in both countries and promote the integration of renewable energy sources such as offshore-generated wind power.