Successful test for the Combined Grid Solution

09.11.2018

The Combined Grid Solution is a joint offshore connection project by the two TSCNET shareholders 50Hertz, one of the four German Transmission System Operators (TSOs), and the Danish TSO Energinet. The binational interconnector in the Baltic Sea will integrate the electricity systems of Denmark and Germany by linking the German wind farm Baltic 2 to the Danish wind farm Kriegers Flak. The utilisation of grid connections from offshore wind farms to couple the transmission grids of two countries is nothing less than a world premiere.

The laying of the two submarine cables “150kV-line KFE-BaZ 155“ and “150kV-line KFE-BaZ 156“ was completed at the beginning of July and the two TSOs have now successfully conducted 24-hour testing of both cables. Around noon on 6 November and in the afternoon thereafter, the two cables were energised one after the other up to the disconnector on the offshore substation OSS KFE and now are ready to transport electricity. Sebastian Wagner, Sub-Project Manager Sea cables at 50Hertz, and Energinet’s Project Manager Daniel Johan Brøndum jointly declared: “Everyone in the team worked closely together and delivered to-the-point. We are very happy and celebrate this success together.”

The submarine cables for the Danish-German offshore interconnector Combined Grid Solution of 50Hertz and Energinet were successfully tested (illustration based on pictures of 50Hertz / Sebastian Wagner)

Linkup
> See 50Hertz project news (html)
> See Energinet project news (html)

See article on single page

Combined Grid Solution: submarine cable installed

06.07.2018

In early May, all of the three offshore platforms for the planned Danish wind farm Kriegers Flak in the Baltic Sea were successfully installed. One of them will not only collect wind power, but also function as linking point for the Combined Grid Solution, the first Danish-German offshore interconnector. The Combined Grid Solution is a joint venture of two TSCNET shareholders, 50Hertz, one of the four German Transmission System Operators (TSOs), and the Danish TSO Energinet.

Just two months later, 50Hertz announces that the next significant step for the project has been taken. The Combined Grid Solution will integrate the electricity systems of Denmark and Germany by linking the German wind farm Baltic 2 with 25 kilometres of submarine cables to Kriegers Flak. Now both cables of the interconnector have been laid out completely. The Baltic 2 platform was the starting point for the cable laying, and on 5 July, the Kriegers Flak platform was reached.

Elke Kwapis, project manager at 50Hertz, acknowledges the good cooperation with Energinet in this process and states: “These are great news. In the business everybody knows how complex the installation of submarine cables can become.” Especially in this case, it was even more challenging than usual, because the Baltic 2 platform was constantly in operation during the cable laying.

The submarine cables for the Danish-German offshore interconnector Combined Grid Solution of the TSOs 50Hertz and Energinet have been laid out. Picture: Screenshot taken from video “Combined Grid Solution (CGS) by 50Hertz and Energinet“ (50Hertz, YouTube)

Linkup
> See 50Hertz press release (html)

See article on single page

CGS onshore transformers on site

03.06.2018

The Bentwisch substation near the city of Rostock in Mecklenburg-West Pomerania is the future onshore converter station for the Combined Grid Solution, the first Danish-German offshore interconnector. The project is a joint venture of two TSCNET shareholders: 50Hertz, one of the four German Transmission System Operators (TSOs), and Energinet, the Danish TSO. The Combined Grid solution integrates the electricity markets of Denmark and Germany by linking the Danish Kriegers Flak wind farm with its German counterpart, Baltic 2. Now another significant step for the interconnector has been taken, as two transformers have been supplied to Bentwisch.

In combination with a double converter system, the large-scale equipment is essential for balancing the asynchronous transmission systems of Germany and Denmark. The transformers were transported from Rostock harbour to the substation per heavy-duty road transport. The second arrived in Bentwisch on the night of 29 to 30 May, and the first three weeks before. “We have thus reached another milestone on the way to commissioning the Combined Grid Solution. The transformers are the most important technical components for the back-to-back system on site,” comments Martin Henschel, specialist engineer at the 50Hertz Northern Regional Centre.

> See 50Hertz press release, in German (html)

Picture: visavis Filmproduktion GmbH

See article on single page

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

See article on single page

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

See article on single page

Kriegers Flak platform foundations installed

27.02.2018

The TSCNET shareholders Energinet, the Danish Transmission System Operator (TSO), and 50Hertz, one of the four German TSOs, are jointly creating the first Danish-German offshore connection in the Baltic Sea, the so-called Combined Grid Solution. For the first time, offshore wind farms will be used for integrating the electricity systems of two countries. The high capacity interconnector will link the German wind farm Baltic 2 with the planned Danish wind farm Kriegers Flak. It is funded by the European Union as a Project of Common Interest.

To collect the wind power from Kriegers Flak, two transformer platforms are needed, of which the larger one will also be used for the Combined Grid Solution. The gravity foundations for these platforms have now been successfully installed in the Baltic Sea at a distance of 8 kilometers from each other. The installation time was about ten hours each. The barge had to be partly subsided below water level, so that the foundations could be unloaded with a special crane vessel. Subsequently, they were lowered to the sea floor. The installation of the platform topsides is scheduled for May 2018.

> See 50Hertz press release (html)

Picture: 50Hertz

See article on single page

Kriegers Flak platform foundations ready

30.01.2018

Europe’s energy future will never succeed without the close cooperation of European transmission system operators (TSOs) and not without the integration of the national transmission systems. This requires high capacity interconnectors, and an example of this is the Combined Grid Solution in the Baltic Sea. The first Danish-German offshore connection will link the German wind farm Baltic 2 with the planned Danish wind farm Kriegers Flak. The Project of Common Interest (PCI) is a joint venture by the two TSCNET shareholders Energinet, the Danish TSO, and 50Hertz, one of the four German TSOs.

After the gravity foundations for the two Kriegers Flak transformer platforms had been assembled on a special barge at the Belgian port of Ostend in December 2017, they were shipped to Denmark early this year. One of the platforms will be used for the Combined Grid Solution. Both are now in Køge harbour in the Danish region of Zealand, 39 kilometres southwest of Copenhagen, where they are waiting for the crane ship for the offshore installation. On the occasion of this project progress, 50Hertz has published an appealing time-lapse video of the platform’s assembly in Ostend, originally produced by the platform manufacturer, the Dutch Jan de Nul Group.

.

Picture: Screenshot taken from video “KriegersFlak Combined Grid Solution – Fundamentbau in 90 Sekunden” (YouTube, 50Hertz)

Linkup
> See 50Hertz press release (html, with link to video)

See article on single page

Foundations for Combined Grid Solution completed

15.12.2017

The Combined Grid Solution will serve as first Danish-German offshore interconnector in the Baltic Sea. By linking the German wind farm Baltic 2 to the planned Danish wind farm Kriegers Flak, which is less than 30 kilometres distant, and thus using the national grid connections of these offshore facilities, the Danish region of Zealand will be connected to the German federal state of Mecklenburg-West Pomerania. The ambitious project, awarded as Project of Common Interest (PCI) by the European Commission, is carried out by two TSCNET shareholders, the Danish transmission system operator (TSO) Energinet and 50Hertz, one of the four German TSOs.

A significant progress for the Combined Grid Solution has now been reported by 50Hertz: The gravity foundations for the two transformer platforms at Kriegers Flak were assembled in the Belgian port of Ostende and are ready for shipping. The assembly consisted of placing the so-called transition pieces on the concrete foundations. The transition pieces are the connecting element between the gravity foundation and the topside of each platform. The larger one of these transformer platforms will be the linking point between the Danish and the German transmission systems.

> See 50Hertz press release (html)

Picture: 50Hertz

.

See article on single page

Sustained benefits from grid extension

03.08.2017

Apart from the generally positive company results, the half-year report of TSC member 50Hertz, one of the four German transmission system operators (TSOs), makes one thing perfectly clear: The TSO’s persistent efforts in extending and improving the transmission grid of its control area in the north and east of Germany are continually paying off.

Despite the ever growing share of the renewables needed to be fed into the transmission system, the costs for congestion management are slightly below the level of previous year. This positive trend is partly due to the extra-high voltage line “Südwest-Kuppelleitung” from the German federal state of Saxony-Anhalt to Bavaria, the first system of which has been commissioned in late 2015. Increased transmission capacities reduce the necessity of interventions, and thus the costs for the TSO – a further proof that grid extension makes effect. The second system of the “Kuppelleitung” will be completed this autumn and then further increase capacities before the coming winter.

Thanks to a sound financial structure, investions in the transmission system have been kept on a high level. A flagship project in this regard is the Combined Grid Solution for Kriegers Flak and Baltic 2. The first offshore interconnector in the Baltic Sea between German and Danish wind farms is realised jointly with the Danish TSO Energinet, a further TSC member. 50Hertz considers transparency and the involvement of the public as crucial for implementing infrastructure projects. To help fostering the acceptance of overhead power lines, the TSO is developing the compactLine, a new generation of less visible pylons with a low height and a narrow corridor. After having received official permit in April, 50Hertz intends to built a pilot model line in Saxony-Anhalt.

> See 50Hertz press release, in German (html)

Picture: 50Hertz

.

See article on single page

Submarine cables for CGS

17.12.2016

The two TSC members 50Hertz, one of the four German transmission system operators (TSOs), and Energinet.dk, the Danish TSO, have concluded a contract with the multinational production company nkt cables on the delivery of submarine cables for their joint interconnection project Combined Grid Solution (CGS).

Two 150kV AC submarine cables are going to connect the Danish offshore wind farm at Kriegers Flak in the Baltic Sea with the German offshore farm Baltic 2, resulting in the world’s first cross-border power connection using offshore facilities. The laying of the cables is scheduled for the middle of 2018, so that the partner TSOs comply with the overall timescale of the Combined Grid Solution, a lighthouse project of the highest importance for the whole European electricity market.

> See Energinet.dk press release (html)

Picture: EnBW / Jörn Tirgrath (Baltic 2 wind farm)

.

See article on single page