Ernsthofen substation

The Ernsthofen substation, which is owned by APG, is one of the largest and most important network nodes in APG’s high-voltage and ultra-high voltage transmission grid. It secures the supply to wide areas in Lower Austria and Upper Austria (Amstetten/Steyr/Wels) as well as in the central region of Upper Austria and Linz (e.g. steel production). Furthermore, it also plays an essential role supra-regionally for the secure supply of electricity and the success of the energy transition throughout Austria.

The existing 220-kV switching station at the Ernsthofen substation acts as a connection point for essential 220-kV transmission lines within Austria. The switching station represents an especially important system for managing grid operations as it connects to the trans-regional, 380-kV transmission network, which it accomplishes via two 380/220-kV grid-coupling transformers.

The 110-kV switching station at the Ernsthofen substation, which is fed from the 220-kV transmission grid via five 220/110-kV grid-coupling transformers, serves to directly supply the 110-kV grid of Netz Niederösterreich GmbH (NEEY grid area in western Lower Austria). It also supplies the Steyr (OÖEH in Upper Austria/Ernsthofen) and Linz grid areas of Netz Oberösterreich GmbH and Linz Netz GmbH, which are connected via APG’s transmission line systems.

The existing 220-kV switching station has reached the end of its useful life. It was built in the 1940s and last (partially) renovated in the 1980s. It is therefore planned to completely rebuild the 220-kV switching station to improve system availability. The rebuild will involve adding a 220/110-kV RHU6 grid-coupling transformer, a 220-kV PST22 phase-shifting transformer and a 220-kV capacitor battery (C-battery) to the 220-kV switching station.