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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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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Cooperation to link offshore wind farms

22.09.2020

Realising the full potential of offshore wind energy in the North Sea will be crucial for the decarbonisation of the European economy and society. The transmission system operators (TSOs), whose control areas border the North Sea, are aware of this, including the Dutch-German TSO TenneT and National Grid from the UK. Both the Netherlands and the UK have set ambitious targets for their respective development of wind capacity in the North Sea. However, to achieve large-scale growth in offshore wind energy, significant amounts of new infrastructure and close cooperation between the countries around the North Sea will be essential.

On 22 September, TenneT and National Grid announced a cooperation agreement to examine the feasibility of interconnecting Dutch and British wind farms to the energy systems of both countries via submarine cables. The announcement is following a recent decision by the Dutch government to secure the first 2GW offshore transmission grids for high-voltage direct current (HVDC) in the Netherlands for the IJmuiden Ver wind farm zone, located some 80km off the Dutch north-west coast. Under the cooperation agreement, TenneT and National Grid will explore the development of a multi-purpose interconnector (MPI) to simultaneously connect up to 4GW of Dutch and British offshore wind energy between the two national electricity systems, thereby creating an additional 2GW of interconnection capacity.

By connecting to both systems, the MPI will allow the use of free transmission capacity for electricity trade between the two countries, thus improving the utilisation of offshore infrastructure – and possibly decreasing the need for additional infrastructure. This will also reduce the environmental impact on coastal communities compared to the current approach of separately developing and connecting interconnectors and wind farms. The two TSOs intend to have defined a “pathfinder project” by the end of 2021 with the aim of creating an operational system by 2029.

Manon van Beek, CEO of TenneT, comments on the agreement: “TenneT has been at the forefront of developing multi-purpose interconnection to enable the large-scale growth of offshore wind in the North Sea. This agreement allows us to work with National Grid in the North Sea to develop innovative infrastructure that uses every spare electron of offshore wind generation to reach our decarbonisation targets.”

TenneT has concluded an agreement with National Grid to investigate the interconnection of UK and Dutch offshore wind farms (exemplary picture: TenneT)

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> See TenneT press release (html)

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ALEGrO on the final straight

17.09.2020

Lichtenbusch near the westernmost German city of Aachen is located directly on the border between Germany and Belgium and is divided into a Belgian and a German part. Right here, on 16 September 2020, the final joint of the “Aachen Liège Electricity Grid Overlay” (ALEGrO) was installed by TSCNET shareholder Amprion, one of the four German transmission system operators (TSOs), and its Belgian partner TSO Elia. Over a distance of 90 kilometres, the DC interconnector with a transmission capacity of 1,000MW connects the Oberzier substation in the German Rhineland region with the Elia substation in Lixhe in the Walloon province of Liège. ALEGrO is the first direct link between the Belgian and German electricity grids and was realised over its entire length by means of underground cables.

The European Project of Common Interest (PCI) provides much needed grid capacity for cross-border electricity flows, while strengthening security of supply in the German region of Aachen-Cologne and the Belgian province of Liège. The cable laying work for ALEGrO started in October 2018 and after twenty months of construction, the civil engineering work was concluded in June 2020. Despite the Covid-19 pandemic, ALEGrO is thus on schedule and nearing completion. The binational power bridge will go into technical operation in October 2020 and will be available to the European electricity market from mid-November. The technical integration of the DC cable into the three-phase grid is a step by step process. The same applies to the parallel market integration. Here, day-ahead capacities are offered first followed by intraday capacities. The allocation of long-term capacities will start in early 2021.

Amprion and Elia installed the final link of the ALEGrO interconnector, which will go into technical operation soon (picture of the project managers Ingo Sander, Amprion, and Dirk Wellens, Elia: Amprion)

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> See Amprion press release (html)

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ALEGrO: Civil engineering concluded

26.06.2020

The cable laying work for the “Aachen Liège Electricity Grid Overlay” (ALEGrO) started in October 2018. The DC interconnector with a transmission capacity of 1,000MW will be the first direct link between the Belgian and German electricity grids and is being implemented as a joint venture by TSCNET shareholder Amprion, one of the four German transmission system operators (TSOs), and the Belgian TSO Elia. The European Project of Common Interest (PCI) provides much needed grid capacities for cross-border electricity flows and at the same time strengthens supply security in the Aachen-Cologne region in Germany and in the Belgian Liège Province. The entire binational power bridge is being realised with underground cabling exclusively.

After twenty months of construction, Amprion now has concluded the civil engineering work on the 41-kilometre-long German section of ALEGrO between the substation in Niederzier and the border to Belgium. “We have reached an important milestone even ahead of schedule,” explains Rainer Millinghaus, Head of Cable Civil Engineering at Amprion. Most of the underground cables have already been drawn into the conduits and only in some sections this still needs to be done. The converter construction site in Niederzier is also making great strides. Here, the DC from the underground cable will be converted into AC to allow connection to the German grid.

The challenging project required different types of cable installation. About 75 percent of the line was built in conventional open construction. However, obstacles like roads or railway tracks were passed with trenchless embedding techniques like horizontal thrust boring or pipe jacking. Also, a modified flush drilling method was used for the first time, which will be beneficial for Amprion in further cable projects, too. Besides these technical aspects, the implementation of ALEGrO is also state-of-the-art in terms of environmental protection: Careful handling of the soil and its hydrologic balance is ensured until the entire installation is completed. An independent soil expert accompanies the construction and recultivation, and there is also an ecological supervision.

Amprion has finished the civil engineering works for the ALEGrO interconnector (picture of Rainer Millinghaus and Theo Heitkamp from ARGE Amprion ALEGrO Aachen welding the last sleeve joint of the conduit system: Amprion)

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> See Amprion press release, in German (html)

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TenneT creates, invests and researches for the energy future

12.03.2020

Promoting the energy transition is a priority objective of TSCNET shareholder TenneT, the Dutch-German transmission system operator (TSO). This is clearly reflected in the TSO’s just-published Integrated Annual Report. As in recent years, the Annual Report is accompanied by the Green Finance Report 2019.

In line with the energy policy and climate goals of the Netherlands and Germany, TenneT increased its investments yet again in 2019 and spent €3.1bn on the energy transition and supply security (grid availability of 99.9998% in 2019). This financial commitment is even to be stepped up: TenneT is planning annual investments of €4bn to €5bn for the future. The financial performance of the company, with revenues of €4.1bn in 2019 and an EBIT (excluding special effects) of €753m, supports these ambitious plans. Manon van Beek, CEO of TenneT, has every reason to be content with the sound development of the TSO: “We have made great strides again in pursuing our ambition to achieve a sustainable energy future for everyone. Not only in realising and developing new onshore and offshore connections, but also by the required far-reaching international cooperation and working on innovations in close coordination with relevant stakeholders.”

As regards offshore connections, TenneT has already exceeded in 2019 the German government’s expansion target for offshore wind power capacity in the North and Baltic Sea, which is 6.5GW for 2020. With last year’s commissioning of BorWin 3, TenneT’s ninth offshore grid connection system in DC technology, the TSO now has a total of twelve offshore grid connections in operation (nine in DC and three in AC technology) with a total capacity of 7.1GW. But TenneT is not resting on its successes to date: The connection systems DolWin5, DolWin6, and BorWin5 are being developed and will increase the offshore transmission capacity provided by TenneT for wind farms in the German North Sea to almost 10GW by 2025. In addition, Borssele Alpha, TenneT’s first offshore connection system in AC technology in the Dutch North Sea, was installed on schedule and is now ready for operation. Borssele Beta will be completed in 2020.

Onshore, TenneT has eight transmission lines under construction in Germany, more than ever before. In the Netherlands, the 60km-long Randstad 380kV North Ring power line was put into operation, reliably supplying Europe’s most densely populated area with electricity and providing transmission capacity for green energy. At European level, the “green” COBRAcable deserves special mention, which since 2019 directly connects the Dutch and Danish markets for the first time. The German and Norwegian markets will also be directly connected by the NordLink cable, which is currently under construction. On top of this, a proof-of-concept for the North Sea Wind Power Hub has shown the technical feasibility of the concept of multiple wind power distribution hubs in the North Sea.

All these grid expansion projects are complemented by innovative solutions and intensive research to better utilise TenneT’s existing transmission system. These include vehicle-to-grid pilots, the deployment of home storage systems in grid stabilisation and digital solutions for higher grid utilisation. Another long-term innovation project is Element One, a 100MW electrolysis plant to be built in Germany to promote an integrated energy system.

TenneT presents Integrated Annual Report 2019 and Green Finance Report 2019 (picture: TenneT)

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> See TenneT press release (html)
> Visit Integrated Annual Report 2019 site (html)
> Direct access to the report download (html)
> Open Green Finance Report 2019 (pdf, 802.38kB)

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COBRAcable proves to be a great success

06.03.2020

It is now half a year since TSCNET customer Energinet, the transmission system operator (TSO) from Denmark, and TSCNET shareholder TenneT, the Dutch-German TSO, made COBRAcable available to the market. The high-voltage DC cable with a length of about 325km and a capacity of 700MW is the first direct connection between the electricity markets of Denmark and the Netherlands. The basic idea behind COBRAcable is to compensate for the volatility of wind power. Consequently, the Netherlands imports electricity via the cable on days with large Danish wind power generation, while on days with little wind in Denmark the electricity is transported in the opposite direction.

This works perfectly, as the interconnector’s transmission data from the first six-month period prove: In total, Denmark has imported almost 700GWh via the COBRAcable and the Netherlands almost 1,400GWh. On average, COBRAcable was operated at full capacity 79% of the time during the last half year. The impressive traffic on this binational connection proves its adequacy through its operation. The new interconnector therefore substantially contributes to the energy transition by exchanging volatile renewable energy across borders and additionally creates a trading profit on the spot market for electricity – a multiple benefit for nature, society and the companies involved.

The transmission data from the COBRAcable of Energinet and TenneT confirm a high level of traffic on the line (picture: screenshot taken from Energinet-video “Constructing the green COBRAcable”, Vimeo)

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> See Energinet press release (html)

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Onshore converter for the Combined Grid Solution

31.01.2020

The Danish-German Combined Grid Solution (CGS) in the Baltic Sea is the world’s first offshore interconnector to use national grid connections of offshore wind farms to link the transmission systems of two countries. For this purpose, submarine cables were laid between the offshore transformer stations of the German wind farm Baltic 2 and the Kriegers Flak wind farm in the Danish part of the Baltic Sea. The CGS is a joint project of TSCNET shareholder 50Hertz, one of the four German transmission system operators (TSOs), and TSCNET customer Energinet, the TSO from Denmark.

The Bentwisch substation near the Baltic port city of Rostock houses the German onshore converters for the CGS. Here 50Hertz has installed a double converter system including a back-to-back converter. This is essential for balancing the asynchronous transmission systems of Germany and Eastern Denmark: The AC from the Nordic synchronous area is converted into DC and directly back into AC, now adapted to the European synchronous area.

50Hertz has now successively energised and commissioned all converter components in Bentwisch. The new equipment and further extensions of the substation had to be individually synchronised with the control technology in a series of individual testing and commissioning steps. The operational readiness of the double converter system in Bentwisch marks another important milestone on the way to the commissioning of the entire CGS.

The German onshore converter for the Danish-German offshore interconnector Combined Grid Solution has been commissioned by 50Hertz (picture: Jan Pauls / 50Hertz)

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> See 50Hertz project news (html)

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ENTSO-E’s MAF 2019 is out now

23.11.2019

The European Network of Transmission System Operators for Electricity (ENTSO-E) has released the new 2019 edition of the Midterm Adequacy Forecast (MAF). In this context, “adequacy” refers to the balance between electricity generation and demand and the forecast is based on a comprehensive mathematical analysis of future pan-European supply security over the period up to 2021 and 2025. The MAF examines not only the interdependencies of supply and demand, but also of storage, climatic conditions, and interconnection capacity. This year, the data granularity and quality were further improved, in particular, with information on thermal generation, an improved hydrological database and a new calculation methodology for demand time series.

The results of MAF 2019 show a low risk for adequacy. However, the MAF also underlines the increasingly important role of cross-border cooperation between transmission system operators (TSOs) in promoting adequacy throughout the interconnected pan-European electricity system. As in the previous issue, MAF 2019 includes a low carbon scenario that considers the impact of the decommissioning of coal-fired plants by 2025. Here the results for some market areas directly or indirectly affected show increased risks. Sources of flexibility such as demand side patterns, storage, interconnections and enhanced and smarter integration of renewable and distributed energy sources are thus required.

The MAF is part of the broader 10-year Network Development Plan (TYNDP), which assesses system needs up to 2040. The results of MAF 2019 will be open to public consultation until 13 January 2020. In addition, ENTSO-E will organise a public webinar on 4 December to discuss the MAF results.

ENTSO-E has released the MAF 2019 (picture: ENTSO-E)

Linkup
> See ENTSO-E press release (html)
> Visit MAF 2019 website with access to appendices and data sets (html)
> Open executive summary of MAF 2019 (pdf, 1.29MB)
> Access to public consultation (html)
> Register for the webinar (html)

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