19.10.2020 – Axpo plans to increase the voltage of its power lines in the Lower Aare Valley (Canton of Aargau) from 50 to 110 kilovolts in order to improve security of supply. Under the project, the line section from the Aare riverbank at Beznau to the substation at the Klingnau hydropower station will be dismantled and replaced with underground cabling. The region will benefit from sustainable energy supply and the ecological enhancement of the recreational area around the Klingnau Reservoir.
The expansion of grid infrastructure is the basis for reliable power supply. In order to meet growing de-mands, Axpo is gradually increasing the voltage of its local distribution grids from 50 to 110 kilovolts (kV). Higher voltage reduces transmission losses by up to 75% and ensures the efficient transport of electricity.
In the course of the voltage conversion, Axpo plans to refurbish several line sections in the Lower Aare Valley. Accordingly, Axpo has submitted the planning approval applications to the Federal Inspectorate for Heavy Current Installations (ESTI). The existing overhead lines will be slightly adapted. In two sections the overhead lines will be replaced with underground cabling. One of these is the line section between Beznau and the Klingnau power plant along the Klingnau Reservoir in the towns of Böttstein, Döttingen, Leuggern and Klingnau:
The decision on which technology will be used – overhead line or underground cable – always takes place under careful assessment and evaluation of various criteria. In addition to the valid power supply and environmental laws, technical aspects, as well as spatial planning issues, environmental compatibility and economic efficiency are taken into account. In addition, the regional and local situation must be considered. In this overall context and in exchange with the responsible authorities and interest groups such as nature, water and bird protection associations, partial re-cabling of the Beznau-Klingnau line was identified as the best solution.
The Aare River landscape at Klingnau belongs to the Federal Inventory of Landscapes and Natural Monuments of National Importance (BLN) and requires special consideration with respect to the environment. The solutions for the voltage conversion in the Lower Aare Valley, which were identified in close cooperation with authorities and interest groups, pay particular attention to this aspect.
Construction will begin in 2021 at the earliest after the ESTI approval and public review. The overhead line sections will be dismantled as soon as all the voltage conversion projects in the region have been completed.