Swissgrid and SiL have renovated their electrical facilities at the Romanel substation. The work has now been completed. Yves-André Bagnoud, Head of the Research & Project Office at Lausanne industrial Services (SiL), tells us about the history of this substation and its importance for SiL.
The Romanel substation is one of the oldest in French-speaking Switzerland. What can you tell us about it?
After the First World War, companies distributed electricity in the region and there were sometimes supply problems. The main producers (including the city of Lausanne) came together to form Energie Ouest Suisse (EOS) and build an electricity transmission line between Saint-Maurice in Valais and Pierre-de-Plan in Lausanne. This line was commissioned on 13 September 1920. Lausanne also supplied electricity to Geneva and the vallée de Joux – thus, the first grid was born. In the 1920s, the general public developed a healthy appetite for electricity, as everyone wanted lighting, hot water and electric hobs.
In 1934, the 125 kV substation was built in Romanel
The Lausanne of the 1930s, for its part, was gripped by construction fever, and voltages had to be increased to distribute electricity, hence the 1934 construction of the 125 kV substation in Romanel. This provided the connection between the local grid and the EOS transmission lines. The substation was expanded over time and, in 2014, the Lausanne city council approved a CHF 18 million package for the renovation of the SiL facilities in Romanel.
How important is this substation for SiL at the moment?
This 220/125 kV substation is essential to the security of the electricity supply in the Lausanne region, together with the Banlieue-Ouest substation in Crissier. Both connect the Lausanne distribution grid to Swissgrid’s electricity transmission grid. These two connections provide redundancy, as the capacity of the Romanel and Banlieue-Ouest substations is the same. In Romanel, the SiL and Swissgrid facilities have been completely renovated and are connected, which is important for the distribution of energy to households and businesses throughout the region.
What exactly has been done at the Romanel substation?
Swissgrid’s facilities and transmission lines are located on the north side, near the local shopping centre. Swissgrid converted an initial building in 2015 to accommodate a 220 kV gas-insulated switching station. The old 220 kV overhead substation, which was well known to the people of Lausanne, could thus be dismantled, freeing up considerable space for two new buildings housing a 380 kV gas-insulated switching station and a 380/220 kV transformer.
To the south, on the Blécherette side, SiL dismantled the old 220/125 kV transformers to construct a new building. Since 2018, it has housed two new 220/125 kV transformers. These transformers are the physical link between the Swissgrid transmission grid and the SiL distribution grid. In addition, there is a gas-insulated 125 kV switching station, two 125 kV/medium-voltage transformers and a medium-voltage switching station (11 kV). The Romanel substation is now ready to fulfil its role as the electricity hub for the Lake Geneva region.
It is worth mentioning that no accidents were reported during construction. The excellent collaboration between the various project partners certainly contributed to this.
The work to modernise the substation is now complete. What were the highlights of the project?
A stand-out moment was when the two 220/125 kV electrical transformers arrived in November 2016. Each of them was delivered separately by a 60-metre long vehicle with a total weight of 327 tonnes, which crossed Lausanne’s city centre at night to avoid disrupting the traffic too much. It was quite a sight!
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