The energy transition leads to an increased need for the transmission of electricity from North Germany, where more and more wind power is being generated both on- and offshore, to the South, where the nuclear power plants are gradually being phased out. This changes the energy infrastructure and makes the further development of the transmission system necessary.
In the scope of this development, another line connection for high voltage direct current (HVDC) transmission is planned. The line will transport electricity from the area of Klein Rogahn, west of Schwerin, to Isar. 50Hertz is planning the northern part of the line between the area of Klein Rogahn and the Börde district near Magdeburg as the SuedOstLink+ project. For this part, a new, separate planning and approval procedure is required.
As of the Börde district up to Isar, the project will use the route of the SuedOstLink. All relevant information can be found on the SuedOstLink project website.
For the SuedOstLink+, the first evaluation of the survey area are being prepared. As for all HVDC projects, SuedOstLink+ must, in principle, prioritise the use of underground cables. In accordance with the Federal Requirements Plan Act, overhead line sections are only possible exclusively in strictly limited exceptions.
In all Grid Development Plans that the transmission system operators have calculated so far, the forward-looking scenarios indicated the need for additional transmission capacity between Mecklenburg-Western Pomerania and Bavaria. The main driver is the constant growth of wind power both on- and offshore. By 2035, an increase in wind turbine capacity by more than 24 GW alone is to be assumed in the north-eastern German states of Mecklenburg-Western Pomerania, Brandenburg and Saxony-Anhalt. The installed capacity of all renewable energy sources in these three states will increase from 26.6 GW in 2019 to 55 GW in 2035.
However, gas-fired power plants and the decentralised growth of renewables will not be able to completely replace the energy production of the nuclear power plants that will be shut down in the South by 2022 as well as that of the coal-fired power plants that are expected to be phased out. In order to make the renewable produced electricity available to consumers in the South of Germany and to ensure both the security of supply and system stability, the SuedOstLink and its extension, SuedOstLink+, should connect the North-East with its windier climate to the load centres in the South.
The transmission system operators calculated the need for additional line capacity in the Grid Development Plans for 2030 of 2017 and 2019 for the respective forward-looking scenarios. As the growth of renewables continues to speed up, the need for additional transmission capacity is more urgent than previously expected. The legislator has taken account of this and included the project in the Federal Requirements Plan Act in February 2021.
SuedOstLink+ is part of project 5a mentioned in the Federal Requirements Plan Act and comprises the northern part between Klein Rogahn, west of Schwerin, and the Börde district west of Magdeburg. The basis for planning and approval is the Grid Expansion Acceleration Act (Netzausbaubeschleunigungsgesetz, NABEG). The procedure is handled by the Federal Network Agency (Bundesnetzagentur, BNetzA) in Bonn.
The procedure is divided into the federal sectoral planning and planning approval. At the end of the federal sectoral planning, the authority determines a route corridor with a continuous width of 1,000 metres for further planning. The subsequent planning approval procedure defines the exact course of the line (‘the route’) within the determined corridor.
SuedOstLink+ is part of project 5a mentioned in the Federal Requirements Plan Act and comprises the northern part between Klein Rogahn, west of Schwerin, and the Börde district west of Magdeburg. The basis for planning and approval is the NABEG. The procedure is handled by the Federal Network Agency in Bonn.
The procedure is split up into the federal sectoral planning and planning approval. At the end of the federal sectoral planning, the authority determines a route corridor with a continuous width of 1,000 metres for further planning. The subsequent planning approval procedure defines the exact course of the line (‘the route’) within the determined corridor.
SuedOstLink+ will transport electricity with a transmission capacity of 2,000 MW at a voltage of 525 kilovolts. The laying of plastic-insulated underground cables with an aluminium or copper conductor is standard. In exceptional cases, overhead lines are still possible on parts of the route.
Because of the length of the connection, the SuedOstLink+ is planned as an high voltage direct current (HVDC) transmission line. This technology is much more tailored to the job at hand compared to the conventional meshed alternating current grid to transmit large electricity volumes across large distances with few losses, optimal control and in a target-oriented manner.
In order to change the alternating current into direct current for further transmission, converters are needed at the grid connection points. One converter will be installed in the area of Klein Rogahn. This converter will likely be connected to the grid via a substation. Another converter in the Börde district is not planned.
The Grid Expansion Acceleration Act stipulates that the Federal Network Agency shall involve the public in the approval procedure several times.
Furthermore, project developer 50Hertz will also inform affected administrations, elected officials, associations, nature conservation organisations as well as citizens on the project milestones and call for hints regarding the plans.