Capacity increase optimises electricity supply in Fricktal region

In the Fricktal region, Axpo has increased the operating voltage of its distribution grid power lines from 50 to 110 kilovolts. This voltage conversion doubles the capacity of existing and additional power lines. The region will now benefit from a sustainable energy supply.

The expansion of the grid infrastructure is the prerequisite for security of electricity supply. To meet growing demand, Axpo is gradually increasing the operating voltage of its transregional distribution grid from 50 to 110 kilovolts (kV). Higher voltage ensures increased capacities, with double the amount of energy transmitted and grid losses reduced by 75 per cent. 

In late October 2023, the ongoing voltage conversion programme reached the Fricktal grid region, where the operating voltage was switched from 50 kV to 110 kV and grid interconnection increased.

Close collaboration with all partners

To enable the voltage increase, Axpo fitted its Münchwilen and Asphard substations with new high-voltage switchgears (110 kV) and new transformers (220/110 kV). High-voltage switchgears and transformers were also converted or upgraded to 110 kV in the following substations of the regional distribution grid operator AEW Energie AG (AEW) and power stations connected to the Axpo grid: Rheinfelden substation, Kaiseraugst substation, Saline Riburg substation, Riburg-Schwörstadt power station, Rheinfelden power station and Augst power station. The voltage conversion was carried out in close coordination with AEW and the operators of the hydropower plants on the Rhine.

Grid connection for Saline Riburg substation

AEW’s substation for the Saline Riburg saltworks, newly connected to the grid, has been more closely integrated into Axpo’s transregional distribution grid. The substation was established at a new location at the Schweizer Salinen AG site, and its predecessor dismantled. Among the prerequisites for the voltage conversion was the completion of technical works on the Saline Riburg substation and linkage of the substation with the new power lines connecting the Riburg-Schwörstadt power station with the Saline site, and Saline Riburg with the Rheinfelden substation. 

The new link from the Riburg-Schwörstadt/Rheinfelden power station line to the new Saline Riburg substation essentially consists of two new terminal towers as well as cabling and earthing works. Two new conduit blocks were also laid between the terminal towers and the new substation, along with empty conduits for the Saline Riburg substation and AEW.

The last phase of the voltage conversion in the Fricktal region will be the upgrading of the existing power line between Rheinfelden and Münchwilen for 110-kV operations, which is scheduled to be operational by the end of 2025.

Voltage conversion

Axpo is gradually converting its existing transregional distribution grid from operating at 50 kV to 110 kV. This will allow more electricity to be transported and grid losses to be reduced by up to 75 per cent. The voltage conversion is making an important contribution to environmentally friendly and efficient grid operation in this regard. The voltage conversion will eliminate bottlenecks and accommodate increasing energy demand.