On July 29th, 2008 the ground breaking ceremony was held for the construction of the new 150 kv switchyard in Innertkirchen. Construction has continued rapidly since then and the building shell is due to be completed mid November – another milestone reached. The switchyard is due to be completed early in 2011 at a cost of approximately 27.6 million Swiss francs.
The next step inside the 45 x 10m shell will be the installation of the 18 fields for the switchgear and the extensive cable tunnels and connections which include an 85m long tunnel.
Planning is also underway for the replacement of the two old 125 mva transformers through a single unit with a capacity of 250 mva. This has a total weight of 300 tons which will be transported by the KWO’s own Meiringen-Innertkirchen train in three single pole phases – which may still prove to be a considerable challenge! The transport is planned for the beginning of 2010.
The new switchyard will enable the old outdoor switchyard, which is over 50 years old and consists of a 150 kv and a 50 kv track, to be demolished.. These installations, with their distinctive high frameworks, were built between 1930 and 1967 and will be replaced by the new internal switchyard. This uses much less room because the high transmission wires are no longer insulated by the surrounding air, instead they are housed in a metal container in which a special gas is used for insulation. This technology is already in use in the switchyards at Handeck and Grimsel 2.
