Amprion Goes Offshore: Expansion and Conversion of the Hanekenfähr Substation

As part of the energy transition, the energy landscape in southern Emsland is undergoing transformation. At the Hanekenfähr site, the Emsland nuclear power plant will be taken offline at the end of 2022. At the same time, increasing amounts of wind energy from the north must be effectively integrated into the grid. In 2028 and 2029, the offshore grid connection systems DolWin4 and BorWin4 will be connected to the transmission grid at the Amprion Hanekenfähr substation. Amprion is addressing this transformation with extensive work at the Hanekenfähr substation. A key measure is the installation of two phase-shifting transformers, which enable better control and optimization of power flows. As part of site clearance, several overhead lines had to be dismantled and implemented as underground cables. egeplast Power Protect PE-RT protective conduits for high and extra-high voltage cables with low-friction inner layer and individual marking were installed, partly trenchless with undercrossing of a railway line.

Lingen in Emsland is traditionally known as an important energy hub in southern Emsland. Currently, the Emsland nuclear power plant still feeds into the Amprion Hanekenfähr substation with a capacity of 1.4 GW, which will be taken offline at the end of 2022. At the same time, the integration of wind energy at the Hanekenfähr site is becoming increasingly important. In 2028 and 2029, Amprion will commission the two offshore grid connection systems DolWin4 and BorWin4 there. Before that, the Hanekenfähr substation will undergo extensive expansion and conversion. This includes the installation of two phase-shifting transformers and the expansion of the facility with several switchgear bays. This requires site clearance through cabling of several overhead lines. This is being carried out as an underground cable system in two construction phases:

Section 1: New construction of a 110 kV high-voltage three-phase connection as underground cable

This connection consists of two 110 kV systems, each with three 110 kV underground cables (connection of the “Rühle-Ost” and “Hanekenfähr-Holthausen” circuits) and runs from the Hanekenfähr substation to the cable termination tower.

The first section was carried out as an undercrossing of the Münster-Norddeich railway line using pipe jacking DN 1,200 mm with a tunnel length of approximately 100 m. Subsequently, two cable protection conduit bundles including accompanying conduits were pulled into the jacking pipe. The second section of approximately 700 m was carried out using open-cut construction.

egeplast Power Protect PE-RT protective conduits for high and extra-high voltage cables with low-friction inner layer and individual marking were used to ensure correct connection to the respective voltage grid during subsequent installation of the underground cables, as civil engineer (M.Sc.) Till Ruland from Heckmann Bau explains: “The high degree of precision required in confined spaces when pulling the conduit bundles into the DN 1,200 mm jacking pipe represents a major challenge. A suitable cable protection conduit system solution is indispensable.”

Section 1: New construction of a 110 kV high-voltage three-phase connection as underground cable

This connection consists of two 110 kV systems, each with three 110 kV underground cables (connection of the “Rühle-Ost” and “Hanekenfähr-Holthausen” circuits) and runs from the Hanekenfähr substation to the cable termination tower.

The first section was carried out as an undercrossing of the Münster-Norddeich railway line using pipe jacking DN 1,200 mm with a tunnel length of approximately 100 m. Subsequently, two cable protection conduit bundles including accompanying conduits were pulled into the jacking pipe. The second section of approximately 700 m was carried out using open-cut construction.

egeplast Power Protect PE-RT protective conduits for high and extra-high voltage cables with low-friction inner layer and individual marking were used to ensure correct connection to the respective voltage grid during subsequent installation of the underground cables, as civil engineer (M.Sc.) Till Ruland from Heckmann Bau explains: “The high degree of precision required in confined spaces when pulling the conduit bundles into the DN 1,200 mm jacking pipe represents a major challenge. A suitable cable protection conduit system solution is indispensable.”