New substation to supply more electricity in the canton of Schwyz

08.02.2017 - Axpo and utility company Elektrizitätswerke des Kantons Zürich (EKZ) are to supply more electricity to the Freienbach/Höfe and March regions by building a new joint substation in Etzel in the canton of Schwyz. Construction work has recently got under way on the project, which will cost around CHF 8 million. Axpo and EKZ will jointly operate the substation once everything is up and running. Axpo is responsible for managing the project.

The new Etzel substation in Altendorf will supply extra power to utility companies Höfe AG and Energie March Netze AG (EMNAG), which until now have drawn their electricity from a single local substation. The additional plant will enhance the security of supply in the Freienbach/Höfe and March regions on a redundant basis.
The regions are seen as fast-growing areas and are expecting a further increase in consumption. Jörg Kottmann, Head Asset Management Grids at Axpo: “With the new substation, we are strengthening the grid and ensuring long-term electricity supply for locals and for Freienbach/Höfe and March, both of which are major commercial hubs. Our partnership with EKZ makes us best placed to exploit synergies from both grid regions when supplying electricity."

Modern technology enables cost-effective construction

The switchgear forms the heart of a substation as it is where the electricity is actually distributed. A gas-insulated switchgear (GIS) is planned for the Etzel substation. One advantage of this model over an air-insulated switchgear is that it takes up less room. This modern technology means that the GIS Etzel substation can be built in a relatively small space, requiring 75% less room than an open-air switchgear.

The step down from high to medium voltage is performed either by a switchable 50-110/16kV transformer or by fixed 50/16kV or 110/16kV transformers. By installing the switchable 50-100/16kV transformer, Axpo will be prepared for a voltage conversion at any time. The Etzel substation will come into service in summer 2018 with a 50kV grid connection and will then be converted to 110kV to increase transmission capacity. Axpo is gradually converting its existing nationwide transmission grid from 50kV to 110kV operations to adapt it to the growing energy demands of the future. The individual regions will therefore benefit from a reliable and sustainable energy supply.