Final court confirmation for Salzburg Line

21.10.2020

From the first submission of the project to the Salzburg state government in September 2012 until the approval of the construction of the second section of the Salzburg Line (“Salzburgleitung”) by the court of last instance, the beautiful Austrian state of Salzburg has certainly seen many sunsets. The Austrian transmission system operator (TSO) APG is now all the more content with the definite legal groundwork for Austria’s most important infrastructure project. Although the legally valid building permit for the Salzburg Line had already been granted by the Austrian Federal Administrative Court in March 2019, there were still final legal details in connection with the project, which the Supreme Administrative Court has now clarified on 20 October 2020, thus confirming the permit.

The new 380kV overhead line will replace the old 220kV line from the 1960s and will be capable of transporting seven times more electricity than the current line. To improve supply security in the city of Salzburg, the first 46-kilometre section of the Salzburg Line from the St. Peter grid node near the German border to the newly constructed Salzburg substation near Elixhausen was already commissioned in January 2011. The second section of the Salzburg Line, from Elixhausen to the Tauern grid node near Kaprun, will now close the western gap in the Austrian “380kV Ring”. This ring-shaped extra-high voltage grid is the backbone of the national electricity supply and crucial for the integration and transmission of renewable energies.

The total length of the new line, which has 449 pylons, is 128 kilometres. However, as old lines will be dismantled when the Salzburg Line is completed and some of them will run jointly on the new line, there will be 229 fewer masts in Salzburg than before. Commissioning of the Salzburg Line is planned for the year 2025, dismantling will be completed by 2026. “With €890m to be invested, the Salzburg Line is by far the most important investment project in the Austrian electricity infrastructure. Of the approx. €350m that APG is investing in the expansion of the electricity grids this year, the Salzburg Line alone has a share of €125m for the domestic economy,” comments Gerhard Christiner, CTO of the Austrian TSCNET shareholder, who also praised the day of the court ruling as a “good day for the energy transition and for the secure supply of electricity in Salzburg and Austria”.

The Austrian Supreme Administrative Court has definitively confirmed the construction permit for the 380kV Salzburg Line of APG (picture: Martin Lugger / APG)

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> See APG press release, in German (html)

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Combined Grid Solution inaugurated

20.10.2020

On 20 October, the world’s first hybrid offshore interconnector was ceremoniously put into operation: the Danish-German Combined Grid Solution (CGS). This interconnector in the Baltic Sea links the transmission grids of two countries via national offshore wind farm grid connections. For this purpose, two submarine cables with a length of merely 25 kilometres and a capacity of approx. 200MW each were laid between the offshore transformer platforms of the German wind farm Baltic 2 and the Kriegers Flak wind farm in the Danish part of the Baltic Sea, which is currently under construction. The CGS – a joint project of TSCNET shareholder 50Hertz, one of the four German transmission system operators (TSOs), and TSCNET customer Energinet, the TSO from Denmark – thus not only connects the platforms with each other but also the existing onshore connections of the wind farms. This allows the transmission of offshore wind power to Denmark or Germany and also cross-border electricity trading.

The official opening ceremony, which took place on site in the German capital of Berlin as well as digitally, was attended by Peter Altmaier, German Federal Minister for Economic Affairs and Energy, Dan Jørgensen, the Danish Minister for Climate, Energy and Utilities, as well as Kadri Simson, EU Commissioner for Energy. With their appearance, these high-ranking political representatives acknowledged the CGS as a technical innovation with model character for future offshore power grids. The hybrid nature of CGS is that it is the first electricity interconnector between two countries, that not only provides capacity for electricity trading, but also transports offshore wind energy onshore – in both directions. The costs of the binational EU-funded project amount to around €300m.

A technical obstacle had to be solved in the realisation of CGS: Because the transmission grids in eastern Denmark and Germany do not operate synchronously, it was necessary to install a back-to-back converter at the 50Hertz substation in Bentwisch near the port city of Rostock in the federal state of Mecklenburg-Western Pomerania. The device converts the incoming AC into DC and immediately back. Only in this way is it possible for electricity to flow smoothly from Denmark to Germany and vice versa. But CGS has not only hardware but also software components. The central digital control unit of the system is the Master Controller for Interconnector Operation (MIO), located in the 50Hertz control centre near Berlin. The MIO balances market requirements with offshore electricity production, which depends on wind conditions in the Baltic Sea. Its main function is to ensure optimum use of the CGS while preventing any overload of the line and the operating facilities in the substation.

Stefan Kapferer, CEO of 50Hertz, commented at the inauguration: “With this project, 50Hertz and Energinet are pioneering the efficient integration of offshore wind farms into the cross-border European electricity market. It offers us several effective options to balance the frequency and voltage of our transmission grids at all times, to deal with the integration of renewable energy sources with more flexibility and to increase the stability of the overall system.” Thomas Egebo, CEO of Energinet, added: “The CGS is not only a very important milestone in reaching Denmark’s ambitious goal of a 100 percent green power system in 2030. The groundbreaking project also delivers an important building block for decarbonising the rest of the society.”

The Danish-German Combined Grid Solution has been ceremoniously put into operation (illustration uses photos of 50Hertz, one of which shows Minister Altmeier)

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> See 50Hertz press release (html)
> See Energinet news release (html)
> Watch CGS inauguration film (YouTube)

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Construction start of Slovenian-Hungarian interconnector

16.10.2020

A glance at the guest list of the official ceremony for the start of construction of the Cirkovce-Pince overhead line reveals that a major project has been launched here. The Slovenian transmission system operator (TSO) ELES had the honour to welcome both the Slovenian Prime Minister Janez Janša and his Hungarian counterpart Viktor Orban to the opening event for the new construction. And indeed, the project is of historic proportions, as the 400kV AC line, a good 80 kilometres long, will be the first interconnector between the Slovenian and Hungarian transmission systems.

The double circuit line with 264 pylons will increase the operational reliability of the Slovenian transmission system and import transmission capacity, facilitate access to energy sources from the North and East, and allow for the integration of larger amounts of renewable energy from the whole region into the grid. The line runs from the Cirkovce substation in the northeastern Slovenian region of Lower Styria to the border settlement of Pince, which is not only on the Hungarian border, but also in the triangle of Slovenia, Croatia, and Hungary. Therefore, in addition to the substation of the Hungarian TSO MAVIR in Hévíz in Zala County, the substation of the Croatian TSO HOPS in Žerjavinec near Zagreb can also be connected to the new line, truly a European Project of Common Interest (PCI). The power line will thus even interconnect three countries. The presence of Gordan Grlić-Radman, Croatian Minister of Foreign and European Affairs, confirmed the trinational dimension of the Cirkovce-Pince line.

At the ceremony with symbolic unveiling of the construction panel, Aleksander Mervar, CEO of ELES, illustrated the supraregional significance of the power line: “This project is of great importance not only for Slovenia but also for the wider region and Europe. That is why this project was included on the list of Projects of Common Interests in 2015, while in 2019 we managed to acquire €50m funds.” Mr Mervar also explained that the project, which includes major upgrades of switchgears in Cirkovce, is the largest investment in transmission infrastructure in the history of ELES, totalling some €150m. Finally, he emphasised the good cooperation of the three TSCNET shareholders ELES, HOPS, and MAVIR: “Without this cooperation, this project would surely not be happening today.”

ELES has started construction of the Cirkovce-Pince 400kV line, which will connect the transmission grids of Slovenia, Hungary, and Croatia (picture: ELES; from right to left: Gordan Grlić-Radman, Viktor Orban, Janez Janša; second from left: Aleksander Mervar)

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> See ELES press release (html)
> Visit project website (html)

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Improving biodiversity for submarine cabling

15.10.2020

Looking at the big picture – the energy transition and the achievement of the European climate targets – there is no alternative to expanding offshore capacity for the generation and transmission of North Sea wind power. For that reason, both the Dutch and German governments have set ambitious targets for offshore expansion, which the Dutch-German transmission system operator (TSO) TenneT is gradually implementing and has even exceeded for its German North Sea control area. In the individual case, however, each offshore construction and operational measure obviously has an impact on the valuable North Sea and Wadden Sea ecosystems. As TenneT strives to apply and monitor nature-friendly solutions in all of its offshore grid projects, the TSO is now conducting pilot tests with stone coverings of submarine cable intersections.

When the TSCNET shareholder lays submarine cables, e.g. currently for the high-voltage connection of the Hollandse Kust (zuid) wind region, the cables sometimes cross with existing oil and gas pipelines. In such cases, the cables protrude above the seabed and are usually covered with a layer of granite to protect them. To replace granite with alternative solutions that promote biodiversity, TenneT has launched a pilot project in collaboration with the offshore specialist company Van Oord. In this project, different types of stones are deposited at cable crossings to investigate which of these stimulates biodiversity best. In total, the pilot involves twelve locations in the North Sea. In the case of the first six, recently laid submarine cables already cross existing oil and gas pipelines. Another six intersections will follow during the construction of the Hollandse Kust (Zuid) connection in 2021.

On 14 October, the different stones were loaded onto Van Oord’s special vessel to be placed at the cable intersections in the coming weeks. Among them are small calciferous stones from a marble quarry, which are placed at three of the six cable intersections. Comparison with the other three intersections without calciferous stones will allow to assess the difference in the type of marine life developing at these intersections. “Our expectation is that the calciferous stones will ensure that various benthic species will find it easier to nest here and that a different habitat will emerge at these sites. Over the years, ‛artificial reefs’ can emerge at these sites in the North Sea, where plants and small creatures can settle,” explains Saskia Jaarsma, Head Offshore Developments and Large Projects Offshore at TenneT.

TenneT has launched a pilot project to promote biodiversity at submarine cable intersections (picture: Van Oord)

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> See TenneT press release (html)

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German field report on underground cabling

07.10.2020

The use of underground cables for power transmission in the extra-high voltage three-phase current range is partly still uncharted technical territory for the four German TSCNET shareholders 50Hertz, Amprion, TenneT, and TransnetBW. As most projects are in the planning, approval, or construction phase, no partial earth cabling project is yet in full system operation, let alone a project with exclusive cabling. However, Tennet has commissioned the Wilhelmshaven-Conneforde line as recently as last week: It is the first 380kV line with underground cable sections in three-phase technology connected to the meshed power grid by the Dutch-German transmission system operator (TSO).

To inform politics and public about the current status of underground cabling in the national transmission system, the four German TSOs have, at the request of the German Federal Ministry for Economic Affairs and Energy, jointly prepared a field report on the use of underground cables in the extra high-voltage three-phase current range. The 65-page report examines seven different key issues in respective main chapters, covering technical, administrative, economic, environmental, and social aspects: dialogue and acceptance, approval procedures and the environment, design and construction, operation and operational safety, underground cable technology, systems engineering, and finally economic efficiency. Key findings of 50Hertz, Amprion, TenneT, and TransnetBW can be summarised as follows:

  • Partial underground cabling does not per se lead to a greater acceptance of line construction projects – compared to the construction of overhead power lines, the concern merely shifts from the residents mainly to landowners and farmers.
  • As far as planning, approval, and construction times are concerned, current experience shows that partial underground cabling requires at least one to two years more than overhead lines. More extensive implementation planning, intensive soil investigations, and negotiations with the owners consumed a great deal of time in the pilot projects. The construction itself is also more complex due to the necessary crossing of infrastructures, 40 to 60-metre-wide aisles, and major interventions in the soil ecosystem.
  • Regarding operational and system safety, underground cable installations have a lower availability rate than overhead lines, as repair times are significantly longer in case of damage. Moreover, with an increasing share of partial underground cabling, the complexity of grid operation and thus the risk to system stability also rises.
  • In terms of economic efficiency, the costs of partial underground cabling are significantly higher than those of overhead lines, and this applies to planning, construction, and operation. Depending on the project-related terrain and soil conditions, the investment costs are usually six times higher.

The four German TSOs have published their joint “Field report on the use of underground cables in the extra-high voltage three-phase current range” (picture: TenneT)

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> See TransnetBW news release, in German (html)
> Open Field Report, in German (pdf, 2.9MB)

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ČEPS half-year report: progress despite pandemic

06.10.2020

The development of European electricity infrastructure cannot be delayed, even in the event of a pandemic. The Czech transmission system operator (TSO) ČEPS has therefore continued in the first half of 2020 – and thus in times of Covid-19 – to comprehensively expand the national transmission system to meet new customer requirements as well as demands arising from international cooperation in the electricity market and to keep pace with the changes in the energy landscape. Notwithstanding the increased challenges, the Czech transmission system was as reliable and efficient as usual during the unforeseen circumstances of the six months and the TSCNET shareholder transmitted 32,000GWh of power.

In the reporting period, the income of ČEPS increased, but also the expenses due to the corona pandemic. This was mainly caused by the need to purchase power balancing services to cope with the decline in electricity consumption during the tense economic situation. Nevertheless, with total revenues increasing in the first half of 2020 compared to the same period of the previous year by nearly CZK 1.1bn to CZK 13,002.5m (about €479,243m), the TSO managed to make a respectable profit of CZK 1.8bn (about €66,344m). “In a year-on-year comparison, total sales from sold licensed services grew the most. After disregarding MC shipping, they accounted for 98% of our total revenues,” explains Martin Durčák, Chairman of the Board of Directors of ČEPS.

ČEPS reports positive figures despite the Covid-19 pandemic for the first half of 2020 (picture: ČEPS)

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Wilhelmshaven-Conneforde line put in operation

05.10.2020

With the Wilhelmshaven-Conneforde line, the Dutch-German transmission system operator (TSO) TenneT has commissioned an important grid expansion project for the German and European energy transition. The 380kV line from the new substation Fedderwarden near Wilhelmshaven on the German North Sea coast to the Conneforde substation in Ammerland, both in the federal state of Lower Saxony, is not only crucial for the transmission of mainly wind power and electricity from regional generators, but also for strengthening security of supply in northern Lower Saxony. Furthermore, it represents a novelty for the TSCNET shareholder in terms of technical implementation: “With this new line, we have put into operation the first pilot project with two underground cable sections in three-phase technology and connected it to the meshed power grid in Germany,” explained Tim Meyerjürgens, COO of TenneT.

The commissioning ceremony on 2 October 2020 in Fedderwarden was attended by representatives from politics, including Andreas Feicht, State Secretary at the German Federal Ministry for Economic Affairs, and Energy and Olaf Lies, Minister for the Environment, Energy, Construction, and Climate Protection of Lower Saxony. The new line is only about 30 kilometres long, but – together with the new construction of the Fedderwarden substation – “of great importance for the entire European electricity trade”, commented Olaf Lies. The Minister was impressed by TenneT’s latest milestone in the energy transition. State Secretary Feicht referred to the newly gained potential for integrating large amounts of wind power into the German electricity market and the technical relevance of the pilot project: “Knowledge obtained in such pilot projects about the construction and operation of the technology will be of great benefit for further power grid expansion in the future.”

The line project was successfully completed after less than two years of construction. Almost 5 kilometres of the line were implemented as underground cables. However, even if TenneT can be satisfied with what has been accomplished so far and is strongly committed to expanding the transmission of green electricity throughout its entire grid area, Meyerjürgens sees a need for further action, especially in view of the increasing offshore wind volumes: “Still, we already see today a further demand for expansion in the Wilhelmshaven and Friesland region.”

TenneT commissioned the new Wilhelmshaven-Conneforde line (picture: TenneT)

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> See TenneT press release, in German (html)

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Tunnel drilling for last section of the Nant de Drance connection

03.10.2020

The Nant de Drance pumped storage power plant in the Swiss canton of Valais is one of the most powerful power plants of its kind in Europe, generating around 2.5bn kWh per year, when it goes fully operational in 2021. The plant has been commissioned successively in sections in recent years. TSCNET shareholder Swissgrid, the Swiss transmission system operator (TSO), is responsible for connecting the power plant to the extra-high voltage grid and for transmitting the hydropower to urban areas in Switzerland. Two of the three sections of the extra-high voltage link to Nant de Drance – an underground cable of 6.5 kilometres between the power station and the Châtelard substation via the access tunnel of the plant and an overhead line of 12.5 kilometres between the Châtelard and La Bâtiaz substations – have been in operation since the end of November 2018.

Tunnel boring has now begun for the third and final section between the substations of La Bâtiaz and Le Verney, which belongs to the municipality of Martigny. The mini tunnel boring machine, weighing around 60 tonnes, was traditionally given a female name on 2 October 2020 at the construction site in Le Verney and will in future be known as Giorgia. Shortly after its christening, it was lowered into the shaft, where it will take around eight months to dig and secure the tunnel between the substations. The tunnel will have a diameter of 2.5m and is dug 12 to 20m deep into the ground. Giorgia is controlled entirely from the control centre at the construction site in Le Verney.

Construction of the underground cable link commenced in June 2020 with the excavation of the shaft at Le Verney and will take two years. The shaft at La Bâtiaz will be dug at the same time as tunnelling work. The finishing work in the tunnel will follow from summer 2021, after which the gantry to connect the Nant de Drance link to the 380kV Chamoson-Romanel overhead line in Le Verney will be built. Finally, the cables will be laid in the tunnel. Commissioning of the 1.2km long underground line is scheduled for 2022. Nant de Drance is already now connected to the transmission grid even before the last section of the link is commissioned: An interim solution was introduced in 2019 by increasing the voltage of one of the two overhead lines between La Bâtiaz and Le Rosel to 380kV.

Swissgrid has started tunnel drilling for the final section of the connection of Nant de Drance to the national 380kV grid (picture: Swissgrid)

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Substantial EU funding for Harmony Link

02.10.2020

The Connecting Europe Facility (CEF) is an important financial instrument of the EU to support targeted infrastructure investments at European level. On 1 October 2020, the coordination committee of the CEF decided to allocate €719.7m for investment in electricity transmission infrastructure in Poland, Lithuania, Latvia, and Estonia. The granting follows an application for funding submitted at the end of May this year by the national transmission system operators (TSOs) of the three Baltic States and by PSE, the Polish TSCNET shareholder.

Harmony Link, which is to be the second interconnector between Poland and Lithuania, particularly benefits: €493m will be directly allocated to the project. Further funding is intended for the upgrading of infrastructure required for the integration of Harmony Link and for the installation of synchronous compensators in the Baltic States.

The first Polish-Lithuanian interconnector is LitPol link, an overhead line connecting the PSE substation in Elk and the Lithuanian Alytus substation, which has been in operation since 2016. Harmony Link is implemented in a different technical way, as a high voltage direct current (HVDC) submarine cable bypassing the Curonian Lagoon and the Gdańsk Bay. The new Polish-Lithuanian interconnector is crucial to enable the synchronisation of the Baltic electricity area with the Continental European (CE) area – an important objective in the framework of the European Energy Union to create a common European electricity market. It will also support regional and supra-regional supply security.

The EU is funding the Polish and Baltic electricity infrastructure with €719.7m through the CEF Energy programme (picture of Gdańsk Bay seen from Gdynia: NAC on Wikimedia Commons, CC BY-SA 4.0)

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> See PSE press release (html)

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TenneT commissions North German grid node

02.10.2020

The town of Wilster is located about 10 kilometres north of the Elbe river in the German federal state of Schleswig-Holstein, which falls within the control area of the Dutch-German transmission system operator (TSO) Tennet. Schleswig-Holstein is of eminent importance for the generation of wind power. In Wilster, after a four-year construction period, the TSCNET shareholder commissioned the renewed Wilster/West substation on 1 October, a significant grid node for the energy transition in the north and beyond. This is because the so-called Westküstenleitung (West-Coast-Line), the NordLink interconnector, which directly links the electricity markets of Germany and Norway, are converging here – and later also the SuedLink “electricity highway” for the transmission of green electricity to the German consumption centres.

For the two high-voltage direct current (HVDC) transmission projects NordLink and SuedLink, the capacity of the former Wilster/West substation was no longer sufficient. An extension of the switchgear was necessary to exclude impermissible load flows and guarantee the short-circuit resistance required in future. Thus, a new 380kV switchgear was built on the ground of the former 380kV substation and the new construction now replaces the old substation on the same site. Furthermore, the connection facilities for the converter stations of SuedLink and NordLink had to be provided. And finally, a 110kV switchgear was installed, which enables the dismantling of the 220kV switchgear in the near substation Itzehoe-West.

“This substation is a central hub for electricity transmission from north to south,” explains TenneT’s COO Tim Meyerjürgens. “Here, electricity from renewable sources is fed into the grid and distributed to regions with high consumption. The Wilster area is of outstanding importance for the energy transition. Because in the grid area between Wilster, Brokdorf, Itzehoe, and Brunsbüttel, three new extra-high voltage lines from TenneT converge: the Westküstenleitung, NordLink, and later also SuedLink.”

TenneT has put into operation the new substation Wilster/West (picture: TenneT)

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> See TenneT press release, in German (html)
> Watch video on the construction and commissioning of Wilster/West, in German (YouTube)

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