Platforms for Combined Grid Solution installed

08.05.2018

The installation of all three offshore platforms for the planned Danish wind farm Kriegers Flak in the Baltic Sea has successfully been completed on 7 May. A special heavy duty crane vessel was needed as the platforms weigh 800, 1,500 and 1,800 tonnes, respectively. The platforms will not only collect the electricity from Kriegers Flak, but one of them will also be used for the Combined Grid Solution, the first Danish-German offshore interconnetor, which is a joint venture of the two TSCNET shareholders 50Hertz, one of the four German Transmission System Operators (TSOs), and Energinet, the Danish TSO.

The Combined Grid Solution will link Kriegers Flak to the German wind farm Baltic 2 and thus integrate the electricity systems of Denmark and Germany. According to Jens Christian Hygebjerg, project manager at Energinet, the platform installation was the “most costly risk” of the whole project. “It is therefore a great relief to see all three platforms in their rightful place.” The platforms are scheduled to be put into operation in October 2018, but only after an intensive phase of further assembly work and a series of tests under real-life conditions.

> See 50Hertz press release (html)
> See Energinet press release (html)

Picture: Jakob Fynsk / Energinet

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Carinthian transformer connected to the grid

27.04.2018

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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First hybrid Statcom facility in Germany

26.04.2018

In the three-phase transmission system, reactive power must be in a well-balanced ratio to active power in order to keep the grid’s voltage on the required level. Without reactive power, the transmission of electricity would not be possible. In the “old” German energy landscape, mainly nuclear and other large power plants have been providing reactive power capacities. Since in the course of the energy transition more and more of these facilities go off the grid, the four German transmission system operators (TSOs) respond with the installation of reactive power compensation systems.

An outstanding example of this is given by TSCNET shareholder TenneT, the Dutch-German TSO, which is expanding the traditional Borken substation in the northern part of the federal state of Hesse to one of the most modern green power hubs of its grid. Here in Borken, practically in the middle of the German power system, the TSO is currently constructing a hybrid static synchronous compensator (Statcom) plant. From the end of 2019, the state-of-the-art facility will dynamically support the mains voltage and provide reactive power at 380kV level, thus making an important contribution to secure grid operation after the shutdown of the large power plants.

The Statcom plant in Borken, with its hybrid construction, will be the first of its kind in the entire German electricity grid. A mayor advantage of this system is its small space requirement ‒ in comparison to its wide reactive power control range. This considerably reduces the environmental impact. In the particular case of Borken, the renaturation of a nearby river has now become possible. Other reactive power compensation measures of TenneT include the new substation Bergrheinfeld/West with its phase shifting and direct coupling transformers. In addition to building new facilities, TenneT is also exploring other ways to provide reactive power, such as utilising wind power and photovoltaic systems.

> See TenneT press release, in German (html)

 

Picture: TenneT

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Second DCT reaches new TenneT substation

19.04.2018

As a result of the energy transition, the four German transmission system operators (TSOs) all are heavily involved in compensation measures to maintain long-term security of electricity supply in light of the decommissioning of nuclear and other large-scale power plants. Since 2015, TSCNET shareholder TenneT, the Dutch-German TSO, has been building the completely new substation Bergrheinfeld/West in northern Bavaria, near the already shutdown Grafenrheinfeld nuclear plant.

Bergrheinfeld/West is one of the projects TenneT considers essential for Germany’s energy future. Hence, the TSO invests about €100m in the new facility which will be one of the most modern of its kind. Already on site are a rotating phase shifter with generator transformer, three compensating coils and the first of two direct coupling transformers (DCTs) to connect TenneT’s supra-regional 380kV transmission grid to the regional 110kV grid. With a transmission capacity of 300MVA each, the transformers can theoretically provide electricity for around one million households.

Today, the second direct coupling transformer was delivered to Bergrheinfeld/West. It was built by GE Grid Solutions in Mönchengladbach and initially transported by ship across the rivers Rhine and Main to the port of Garstadt, where it was reloaded onto a 67-meter heavy-duty road transport unit. The transport weight of the transformer is about 260t, and the subsequent operating weight of both units will be 370t each. Preparations for the initial set up of the transformers are expected to be finished in July 2018, followed by the commissioning of the substation’s 380kV system section. The completion of the entire Bergrheinfeld/West substation is scheduled for 2019.

> See TenneT press release, in German (html)

Picture: TenneT

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Upgrade in Lower Austria

18.04.2018

The Austrian transmission system operator (TSO) APG maintains its sustained efforts to make the Austrian transmission grid future-proof. The TSCNET shareholder is investing €30m to modernise and expand the Ternitz substation in Lower Austria’s Industrieviertel. A new 220/110 kV transformer is the centrepiece of the retrofitted facility.

The 245-tonne high-tech device was delivered to Ternitz on 16 April. The transformer was transported from the manufacturing site in Weiz in eastern Styria via train and for the last few kilometres by means of heavy-duty road transport. With the substation upgrade, TSCNET shareholder APG ensures fail-safe operation and long-term security of electricity supply in the Industrieviertel, Upper Styria and in the Styrian Mürz valley. The completion of all reconstruction and modernisation measures is scheduled for 2020.

> See APG press release, in German (html)

Picture: APG / Martin Wieland

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Transformer for Combined Grid Solution

06.04.2018

At the Hollandia shipyard in Krimpen aan den IJssel in the Dutch province of South Holland, the next step has been taken for the Combined Grid Solution, the first Danish-German offshore connection in the Baltic Sea: A 450MVA transformer was placed on the Kriegers Flak Extension offshore platform. The interconnector is a joint venture by the two TSCNET shareholders 50Hertz, one of the four German Transmission System Operators (TSOs), and Energinet, the Danish TSO.

By linking two offshore wind farms, the German Baltic 2 and the planned Danish Kriegers Flak, the Combined Grid Solution will integrate the electricity systems of both respective countries. The transformer is necessary to balance the different voltage levels of the Danish and German offshore wind farms. After the complete assembly of the transformer, the entire platform topside will be shipped to Kriegers Flak at the end of April. Here, it will be installed on the gravity foundation, which has been erected in February of this year on the floor of the Danish Baltic Sea.

> See 50Hertz press release (html)

Picture: Dieter Böhm / 50Hertz

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New transformer in Upper Austria

05.04.2018

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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Delivery of West-Coast-Line transformers

20.12.2017

The substation Heide-West in the most northern German federal state of Schleswig-Holstein is an important node of the “Westküstenleitung” (“West-Coast-Line”), which is planned and currently constructed by TSCNET shareholder TenneT, the Dutch-German transmission system operator (TSO). This 380kV power line with a length of about 140km is one of TenneT’s numerous projects to transmit green electricity generated by wind farms in the German north to the main consumption centres in the west and south. The “West-Coast-Line” will also enhance transmission capacities between Denmark and Germany.

In the course of this week, two direct coupling transformers, the core elements of the substation, are to arrive at Heide-West. With a capacity of 300MVA each, they are capable of transforming electricity for around one million households. By connecting TenneT’s extra high-voltage grid to the 110kV grid of the local distributor, the transformers ensure the integration of wind power into the supra-regional transmission system. The transformers reached the port of Büsum by ship earlier this month, and since they both have a transport weight of 260t, they will be delivered individually in the period from 20 to 23 December by means of heavy-duty road transport.

> See TenneT press release, in German (html)

Picture: TenneT

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TenneT transformers ensure supply in northern Bavaria

23.06.2017

The electrical substation Bergrheinfeld West of TSC member TenneT, the Dutch-German transmission system operator (TSO), in the north of the German federal state of Bavaria is yet under construction but will be one of the most modern facilities of its kind in Germany. In order to maintain the regional supply security also after the shutdown of nuclear and other large power plants, TenneT considers the new substation – near the former nuclear plant in Grafenrheinfeld – to be essential. The TSO invests about €100m in the new facility.

In the night from 22 to 23 June, the first of two direct coupling transformers built by GE Grid Solutions was delivered to Bergrheinfeld via heavy-duty road transport. Prior to that, the unit had been moved from its production site in Mönchengladbach by ship over the rivers of Rhine and Main to the harbour of Garstadt.  On the last few kilometres, a 72-metre-long vehicle-train with 32 axles, a special trailer, and a total weight of 526t carried the high technology device. Since the transformer was shipped without add-on parts and insulating oil, its transport weight amounted to 260t, which is significantly lower than the subsequent operating weight of about 370t.

The direct coupling transformers will connect TenneT’s supra-regional 380kV transmission grid to the regional 110kV grids and thus constitute the core component of the substation. With a transmission capacity of 300MVA, the devices can provide electricity for around one million households. While the preparation for the commissioning of the first transformer will take about three months, the second one is expected to be delivered in February 2018. The completion of the whole substation Bergrheinfeld West, including a rotating phase shifter with generator transformer and compensating coils, which both are already on-site, is scheduled for 2019.

> See TenneT press release, in German (html)

Picture: Screenshot taken from video “Umspannwerk bei Bergrheinfeld. 260 Tonnen-Trafo wurde verladen” (Bayerischer Rundfunk)

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Grid extension in northern Switzerland

28.03.2017

Although the grid situation in Switzerland is stable and the supply security is at no concrete risk, the grid operation in the alpine winter is usually strained and challenging for TSC member Swissgrid, the Swiss transmission system operator (TSO). This was especially true of the severe winter of 2015/16 and is one more reason for Swissgrid to accelerate the grid extension in Switzerland according to “Strategic Grid 2025”, the TSO’s ambitious grid modernisation and expansion plan.

An important part of “Strategic Grid 2025” is the upgrade of the electrical substation Beznau in the Swiss Canton of Aargau including a new 380/220 kV transformer. After the Swiss Federal Inspectorate for Heavy Current Installations (“Eidgenössisches Starkstrominspektorat”, ESTI) had approved Swissgrid’s upgrading plans in July 2016, the preparatory work in Beznau started immediately. In November 2016 and January 2017 the transformer was delivered to Beznau in three segments via heavy-duty transport. After some test runs the new transformer has now been put into operation.

The new device – situated on an island in the middle of the river Aare in Beznau and operated by Axpo Power AG – is not intended for operating constantly but as a backup for critical grid situations. Hence it is designed to be activated by Swissgrid on short notice. The transformer supports import capacity in the northern Swiss border region and improves the supply security in metropolitan area of Zurich.

> See Swissgrid press release (html)

Picture: Swissgrid

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