The Südostlink, which will transport wind power from northern and eastern Germany to Bavaria, should actually have been in operation since the end of 2022. Together with the other electricity highway, the Südlink, it is intended to fill a large part of the gigantic electricity gap that was created by the shutdown of the nuclear power plants. But the population in the regions through which the electricity highway will one day run and key politicians such as former Prime Minister Horst Seehofer (CSU) and today’s Deputy Prime Minister and Energy Minister Hubert Aiwanger (Free Voters) have long categorically rejected the project. Aiwanger said three years ago, when he was already energy minister: “My statement is that I don’t want any of these routes.” It was only a year ago that Aiwanger publicly acknowledged his support for the Südostlink.
This Monday, almost nine months after the shutdown of the Isar 2 nuclear power plant, construction of the southeast link finally begins. It is a happy day for the developer of the electricity highway in Bavaria, the network operator Tennet. “The start of construction is a milestone on the way to a secure, independent and cost-efficient power supply in Bavaria,” says Tennet boss Tim Meyerjürgens. Private households will receive their electricity via the Südostlink, as will trade, industry and technology companies. Tennet is holding a ceremony to mark the start of construction. Numerous business people and representatives of authorities, associations and parties are expected. Prime Minister Markus Söder and his deputy Aiwanger also arrive and give greetings.
A detail of the start of construction shows how massive the pressure is now for the new electricity highway to finally come. Tennet begins construction of the high-voltage direct current (HVDC) transmission line, as the Southeast Link is called in technical jargon, without final approval. The Federal Network Agency, which will issue it next year, has allowed the network operator to start construction early. Something like this is only possible when a project is particularly pressing. Thanks to the early start of construction, important preparatory work can begin on the site near the former Isar 2 nuclear power plant. In general, Tennet is now rigorously using all possibilities to accelerate the construction of the Southeast Link, especially by shortening procedural steps that the EU and the federal government, but also the states, have made possible for the company. Ultimately, the electricity highway should be partially operational in 2027 and be completely finished in 2030. That’s no longer four years for one construction phase.
The Southeast Link is a gigantic project. It actually consists of two high-voltage direct current transmission lines. Each of them has two gigawatts of power. For comparison: the Isar 2 nuclear power plant, which was one of the most powerful in the world, had a gross electrical output of almost 1.5 gigawatts. The federal government has chosen direct current technology for the Südostlink and other electricity highways because the energy losses during transport are very low. This makes them ideal for long distances. One branch of the southeast link starts in Wolmirstedt in Saxony-Anhalt, the other in Klein Rogahn in Mecklenburg-Western Pomerania. The two branches are 538 and 758 kilometers long. Around 270 kilometers run through the Free State. The Bavarian section begins in the Hof district, leads through the Fichtel Mountains and along the Upper Palatinate Forest to Weiden and towards Schwandorf and crosses the Danube east of Regensburg.
Five billion euros are being buried in Bavaria alone
The costs are also impressive. Tennet expects eleven billion euros for the entire project. In Bavaria alone, around five billion euros are buried. The central cost driver is that the electricity highway is being laid as an underground cable and not as an overhead line. After years of dispute, the then Prime Minister Seehofer made his approval dependent on this. Nobody knows exactly how much more expensive an underground HVDC line is compared to an overhead line because there is a lack of experience. But for conventional power lines, network operators calculate by a factor of four to eight – depending on the surface. This cannot be transferred one-to-one to HVDC. But there is a sense of the difference.
Construction begins at the end point of the electricity highway near the former Isar 2 nuclear power plant. Two so-called converters will be built there, one for each southeast link branch. In the systems, the direct current that arrives via the electricity highway is converted into alternating current so that it can be distributed via the high-voltage network to the metropolitan areas of Munich, Regensburg and Ingolstadt, but also to the southeast Bavarian chemical triangle. A converter can also convert alternating current into direct current. This is the prerequisite for the Southeast Link to also be able to transport electricity in the opposite direction.
The converters are also gigantic systems. Tennet expects a space requirement of 45,000 square meters. If you add the edge strips as well as the areas for drainage, access roads and other things, the space requirement increases to 60,000 square meters, or six hectares. The center of the system is the approximately 20 meter high converter hall with the converter modules in which direct current is converted into alternating current. Next to it are cooling modules with which the converters are kept at operating temperature. You also need a direct current and an alternating current switch panel, as well as transformers and an operations building from which everything is controlled and monitored.
Energy Minister Aiwanger now even wants a third electricity highway
Under the impression of the enormous energy gap in Bavaria after the shutdown of the Isar 2 nuclear power plant, Aiwanger has obviously turned into an electricity highway fan. The former critic recently even called for a third HVDC transmission from northern Germany to the Free State. “The electricity needs of Bavarian industry and for hydrogen production are underestimated,” said the cabinet, justifying the initiative. Aiwanger had already pointed out to the network operators that the electricity requirements of Wacker Chemie alone and the other companies in the southeastern Bavarian chemical triangle will increase from today’s 3.8 billion kilowatt hours of electricity per year to up to 17.7 billion kilowatt hours as part of the switch to climate-neutral production Current will increase. There was great surprise in the energy scene about Aiwanger’s insight.
In the SZ, Aiwanger did not want to comment on his change of heart. Instead, he had a spokesman announce: “In view of the far-reaching energy policy developments of the last few years and as a result of the war in Ukraine, the importance of the southeast link for Bavaria has increased.” In addition, the demand for electricity is increasing as industry, households and transport switch from fossil to climate-neutral energies.
By the way: The network operator had already proposed the third electricity highway to Bavaria to the Federal Network Agency before Aiwanger made the Free State’s demand public.