Bayreuth/Berlin, 31 May 2021 – The SuedOstLink direct current (DC) connection, a major grid development project which will enable the energy transition in Germany, is now one step closer to being realised. 50Hertz and TenneT, the two transmission system operators developing the connection, have placed an order with Siemens for the construction of the converter systems which will link both ends of the connection to the existing alternating current grid. 50Hertz is responsible for the part of the SuedOstLink which will run from Saxony-Anhalt to the Bavarian border, whereas TenneT is responsible for the section which will run through Bavaria.
Both transmission system operators launched a joint call for tenders for the two converters, as they form a single technical unit. Having won the contract for the tender, Siemens will deliver both converter systems to the project developers.
‘The placement of the order for the converter systems brings us a good deal closer to the realisation of this power link that is so important for the energy transition,’ said Tim Meyerjürgens, COO of TenneT. ‘TenneT already has many years of experience in laying underground DC cables on land and at sea, as well as in the secure operation of these systems,’ Meyerjürgens continued. ‘The SuedOstLink converter will be the 29th converter in our grid.’
‘The SuedOstLink is a decisive step in achieving our objective of integrating 100% of renewable energy into our grid and system by 2032,’ said Dr Frank Golletz, CTO at 50Hertz. ‘After the placement of the order for the SuedOstLink underground cables in May 2020, this is the second important order we have carried out for project.’
The site for the northern converter in 50Hertz’s area has already been determined: it will be built at the Wolmirstedt substation to the north-west of Magdeburg. Certain systems belonging to the existing substation can be used for the new project. Moreover, the substation is the most connected central grid node in the north-east of Germany, where high amounts of wind power are produced.
The southern converter in Bavaria will be constructed in the Landshut area, near the Isar grid connection point. TenneT is currently exploring four potential converter sites based on a scoping study published in October 2020 by the Federal Network Agency, which is responsible for granting the construction permit for the project. The Agency has the ultimate say about the site for the converter; it will publish its decision regarding the site at the same time as its decision about whether or not to grant planning approval for the project.
The converter systems each require a surface of approximately 4.5 hectares in order to be built. The entire construction phase, including commissioning, is expected to take three and a half years. The costs for both converter systems amount to several hundred million euros. The total cost of the SuedOstLink is around four to five billion euros.
Converters are needed to transform alternating current into direct current and vice versa. In order to transport the alternating current generated by wind turbines in the north and east of Germany to the densely populated areas and industrial centres in southern Germany (whilst minimising losses), it is converted into direct current at the northern converter station and then converted into alternating current again at the southern converter station.
The SuedOstLink project, alongside the process for awarding the contracts for both converter systems, was outlined in the Federal Requirements Plan Act (Bundesbedarfsplangesetz, BBPlG). The most recent amendment to this Act (carried out by the Bundestag and Bundesrat) specified that the SuedOstLink should be expanded to include another direct current system with an additional transmission capacity of 2 gigawatt. This project (known as Project 5a) will run from the Klein Rogahn area (to the west of Schwerin) to the west of Magdeburg (in the Börde district) and along the SuedOstLink route. One converter in Klein Rogahn to the west of Schwerin and one in the Isar area are required for project 5a. Another call for tenders for the construction of these additional pieces of infrastructure is due to be launched soon.
Volker Kamm: T 030/5150-3417, M 0172/3232759, E volker.kamm(at)50hertz.com
Ulrike Hörchens: T 0921/50740-4045, M 0151/17131120, E ulrike.hoerchens(at)tennet.eu