Substation upgrade in the Swiss Espace Mittelland


The Innertkirchen substation in the Swiss canton of Bern is an important hub of the national transmission system. As the old 220kV open air switchgear at Innertkirchen is somewhat outdated, TSCNET shareholder Swissgrid, the Swiss transmission system operator (TSO), replaces it with a 380kV gas-insulated switchgear (GIS). The substation modernisation is not only important for the regional long-term security of electricity supply, but also for ensuring the transmission of green energy from hydropower plants in the cantons of Bern and Valais to the centres of the Mittelland.

The conversion work started with a symbolic turn of the sod on 15 May. Since the building for the new GIS will be erected next to the existing outdoor switchgear, the operation of the substation can be fully maintained during the construction period. Investments for the entire project amount to around CHF33m, and commissioning of the new facility is scheduled for mid-2021.

> See Swissgrid media release, in German (html)

Picture: Swissgrid

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Carinthian transformer connected to the grid


The substation in Obersielach in the southernmost Austrian state of Carinthia is an essential component of the nationwide modernisation process, with which TSCNET shareholder APG, the Austrian transmission system operator (TSO), adapts its grid to the high requirements of a sustainable energy future. Last September, a large additional 380/220kV transformer was delivered to Obersielach ‒ due to its heavy weight in three parts – and then it took six months of installation work and extensive functional testing, before the new device could finally be connected to the grid on 26 April 2018. Further upgrade measures at the substation are still pending and completion is scheduled for autumn 2019. Overall, APG is investing round €38m in the operating site.

The Obersielach substation is the most important power hub in Carinthia and one of the largest substations in Austria. The commissioning of the new transformer will not only ensure the regional long-term security of electricity supply, but also improve the use of climate-friendly wind energy by means of interconnecting the wind farms in Upper Austria with the Carinthian pumped storage power plants in Malta and Reißeck. Surplus wind power can thus be transported to these “green batteries” and stored there. If necessary, the electricity can then be retrieved again from the storage power plants. Apart from that, the five largest Carinthian hydropower plants on the river Drau feed directly into the Obersielach substation.

> See APG press release, in German (html)

Picture: Erich Varh / APG

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New transformer in Upper Austria


In order to secure the long-term security of electricity supply in the Western Mühlviertel in Upper Austria as well as to improve the supply situation in the greater Linz area, TSCNET shareholder APG, the Austrian transmission system operator (TSO), is upgrading its substation near the Jochenstein Danube hydropower plant on the Austro-German border. These modernisation measures include a new 220/110kV transformer.

In September 2017, the 280-tonne transformer was delivered by ship across the Danube to Jochenstein. After five months of assembling and extensive functional tests under high-voltage, the state-of-the-art device was finally connected to the grid at the end of March 2018. The commissioning marks the completion of all construction work at the substation, with which APG ensures that green electricity from the Jochenstein hydropower plant continues to be safely fed into the Austrian transmission system. In total, APG invested €10m in the supply security of the region.

> See APG press release, in German (html)
> See APG video with background information, in German (html)

Picture: APG / APA-Fotoservice / Hautzinger

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Line upgrade in the Engadin Valley


A symbolic cut of the spade was the starting signal for the elimination of the bottleneck within the Swiss as well as the whole European transmission system, which is the power line in the Engadin Valley between Pradella and La Punt. To enhance the existing line with a length of 49 km, TSCNET shareholder Swissgrid, the Swiss transmission system operator (TSO), appends an additional 380kV circuit. Swissgrid also modernises the Pradella substation by substituting the old overhead station with a 380kV gas insulated substation.

The construction projects in Engadin are part of “Strategic Grid 2025”, Swissgrid’s demanding grid modernisation and expansion plan. They will increase grid stability and supply security in Switzerland. By providing capacities for the transmission of electricity from Grisons hydropower and by reinforcing interconnections to Italy and Austria, the building measures have beyond that a considerable European dimension. Preparatory works for the line upgrade started in the summer of 2017 and the commissioning of the expanded power line is expected in autumn of 2021. The new Pradella substation will probably be connected to the grid in 2020.

> See Swissgrid media release (html)

Picture: Swissgrid


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Modernisation of Pleinting substation


Currently, TSC member TenneT, the Dutch-German transmission system operator (TSO), modernises several of its substations. In doing so, the TSO improves the coupling of regional electricity grids to TenneT’s trans-regional transmission system and pursues three main targets: Meeting the challenges of the energy transition, ensuring grid stability, and enhancing the supply security.

One of those upgrade projects is the substation Pleinting in Lower Bavaria, near Passau and close to the Austrian-German border. The Pleinting substation is of significance for the cross-border electricity exchange, in particular for the linking of Austrian pump storage power plants to the German grid. For this reason, also the overhead power line from Pleinting to the Austrian substation St. Peter am Hart is presently being overhauled. These reconstruction works will probably be finished by April, while the modernisation of the substation is scheduled to last til 2020.

Since transformers are the centrepiece of any substation, the upgrade of Pleinting involves a complete new set of such devices. Today a direct coupling transformer weighing 260t is arriving at Pleinting by means of heavy-duty transport. The assembly of the new machine built by GE Grid Solutions will take up to three month and two more transformers are expected to be delivered until 2018.

> See TenneT press release, in German (html)

Picture: TenneT


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Approval to finish Nant de Drance connection


In late 2016, the Swiss Federal Inspectorate for Heavy Current Installations (“Eidgenössisches Starkstrominspektorat”, ESTI) has approved the construction plans for the final section of the grid connection of the Nant de Drance pump storage power plant as submitted by TSC member Swissgrid, the Swiss transmission system operator (TSO). Hence, all building permits for the connection of the plant in the Swiss Canton Valais near the French border to the Swiss transmission system have been granted and the implementation of the complete project now can proceed as scheduled.

Swissgrid originally intended to realise the last 1.3km from the La Bâtiaz substation to Le Verney, the connecting point to an already existing 380kV extra-high voltage line, as overhead line. According to revised plans, the Rhône valley between La Bâtiaz and Le Verney will now be crossed by means of an underground cable laid at a depth of 25 to 30 metres. Currently, Swissgrid is elaborating the technical details of this deep cable solution. The TSO will make those details known to the public once the planning and tender procedures are completed.

> See Swissgrid press release (html)

Picture: Screenshot taken from video “Nant de Drance – Höchstspannungsnetz” (Swissgrid, YouTube)


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New transmission line to connect Nant de Drance


TSC member Swissgrid, the Swiss transmission system operator (TSO), has emphasised the indispensability of upgrading the extra-high voltage grid in the Swiss Canton Valais persistently. The upcoming commissioning of the Nant de Drance pump storage power plant near the French border in 2017 is likely to increase the already tense situation for the transmitting of hydropower in Valais. Now the Swiss Federal Inspectorate for Heavy Current Installations (ESTI) has approved construction plans for the last section of a new 380kV line. This additional overhead line from the substation Châtelard to the substation La Bâtiaz is essential to transporting electricity generated by Nant de Drance. Swissgrid announced on 13 May 2016 the granting of the final missing building permit. The approval also includes the replacement of the La Bâtiaz station.

The new extra-high voltage line is going to have a total length of 12.5km. It will replace the already existing 220kV line. Construction work is set to start this summer and planned to be completed in spring 2017, followed by the dismanteling of the old line.

> See Swissgrid press release (html)

Picture: Nant de Drance SA

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Study on Hydropower


The Austrian electricity company Verbund is one of Europe’s largest producers of electricity from hydropower in Europe and a member of the European Hydropower Initiative. Now the initiative published its youngest macro-economic study on behalf of 21 European hydropower companies and associations: “The hydropower sector‘s contribution to a sustainable and prosperous Europe.”

> See Verbund news (html, in German)

> Open Presentation of study results (pdf, 1.52mb, in English)

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