NordLink: Launch of laying the ‘green link’

The installation of the NordLink high-voltage cable between Norway and Germany has begun. The first few kilometres of the ‘green link’ have already been laid on the seabed in Vollesfjord, in the Vest-Agder region of southern Norway. For the first time, the interconnector will directly connect the energy markets of Germany and Norway for the exchange of Norwegian hydropower and German wind energy. NordLink is jointly implemented by project partners TenneT, the German promotional bank KfW and the Norwegian transmission system operator Statnett.

‘We have been working on this project for several years, and it is very exciting to get started on the actual cable installation. We have now attached the cable to shore through a microtunnel from the head of the fjord, before the cable installation ship could head out for the open sea’, said Executive Vice President Håkon Borgen, Statnett.

‘The work is right on schedule’, said Lex Hartman, a member of the management board of the transmission system operator TenneT, in light of the planned completion of the interconnector by 2020 ‘on the German side, we are already installing the ducts for the cable under the land protection dike near Büsum.’ The actual launch of laying the subsea cable in the German North Sea is planned for summer 2018. ‘NordLink connects two perfectly complementary systems for the exchange of renewable energy: German wind and solar power on the one side, and Norwegian hydropower on the other’, said Hartman, ‘only projects such as NordLink enable an integrated European energy market. To ensure that energy is directed to where it is needed. Easily, safely, and eco-efficiently.’

‘NordLink stands for energy transition. The possibility of flexible exchange of renewable energies makes a decisive contribution to the reduction of CO2 emissions. The interconnector contributes to the achievement of climate targets and increases the reliability of supply in both countries’, said Gisela von Krosigk, Senior Director of the KfW IPEX-Bank, who is responsible for the project within KfW.

The first part of laying the submarine cable, started today, will be routed from Norway this summer: 134 kilometres from Vollesfjord to the Danish territorial waters of the North Sea. The cable weighs up to 70 kilograms per metre and is laid by the cable lay vessel ‘Nexans Skagerrak’. It is followed by the offshore vessel ‘Polar King’, which buries the cable in the seabed at a depth of up to two metres with a special underwater plough – depending on the condition of the seabed. The cable consists of two strands laid in parallel, the plus and minus pole, and was manufactured by Nexans in the Norwegian Halden.

Starting in 2018, another 228 kilometres will be routed from the Danish North Sea area to the border of German territorial waters. Subsequently, starting in 2018, another 154 cable kilometres will be added from the coast near Büsum (Schleswig-Holstein), starting in the mudflat.

In the German section, the two subsea cable strands are bundled and installed in one single operation, i.e. at the same time, and are buried in the seabed. On the high seas, the cable ends are combined. A 54-kilometre underground cable from Büsum to the Wilster converter station will be added to the 516-kilometre-long subsea cable on the German side. Here again, everything is on schedule: The groundbreaking ceremony in Wilster already happened in September 2016, and large parts of the buildings for service facilities and converters have already been built there.
Laying the underground cable is already scheduled to start in 2018.
On the Norwegian side, the subsea cable was successfully connected to the cable transition system at the Vollesfjord landing point today, where it is connected to a direct-current overhead line leading to the Norwegian converter station near Tonstad. There, the buildings are now largely erected and the first four out of seven large transformers were installed by ABB.

In the converter stations, the transmitted direct current is subsequently converted into three-phase electric power and connected to the Norwegian or German high-voltage grid.

With NordLink, the ‘green link’, one of the longest systems for high voltage direct current transmission (HVDC) in the world is being developed. The total interconnector will have a length of 623 kilometres, including 516 kilometres of subsea cables. NordLink has a capacity of 1,400 megawatts (MW). This places its capacity considerably above that of a large conventional power station.

German consumers can benefit from the positive effect on electricity prices resulting from the import of lower-priced hydropower. A considerable part of the socio-economic advantages of NordLink results from the profits generated by trading transmission capacity via the interconnector. These profits will be used to fund other network projects or to lower energy rates.

Background
NordLink is the first interconnector to provide a direct link between the Norwegian and German energy markets. This connection promotes the integration of the north-west European energy market, increases market efficiency and contributes to a stabilisation of energy prices. When limited activity of wind turbines and solar cells result in higher energy prices in Germany than in Norway, energy generated by Norwegian hydropower plants can be imported via NordLink. The power line connects the capacities of Norwegian hydropower plants with those of wind and solar farms in Germany. The Norwegian water reservoirs essentially function as ‘energy reservoirs’: the water inside them is retained when energy is imported from Germany. In turn, they can come into play during peak consumption periods in Germany, and when there is little production from solar and wind power plants. Then Norwegian hydropower is transported to Germany.

German-Norwegian cooperation
The NordLink project will be implemented by the Norwegian TSO Statnett and DC Nordseekabel GmbH & Co. KG, each with 50% ownership. TenneT and KfW both have share 50% ownership in DC Nordseekabel. DC Nordseekabel is responsible for the construction and approvals on the German part of the project.

Facts and figures

· 623 km long, high-voltage direct current transmission (HVDC)

· A capacity of 1,400 MW at ± 525 kV

· Offshore: 516 km subsea cable

· Onshore: 54 km of underground cable (Büsum – Wilster/Schleswig-Holstein) and a 53-km overhead line (Vollesfjord – Tonstad/NOR)

· Grid connection points: the Wilster (GER) and Tonstad (NOR) substations

· To be completed by 2020

TenneT
TenneT is a leading European electricity transmission system operator (TSO) with its main activities in the Netherlands and Germany. With over 22,000 kilometres of high-voltage connections we ensure a secure supply of electricity to 41 million end-users. We employ approximately 3,000 people, have a turnover of EUR 3.2 billion and an asset value totalling EUR 19 billion. TenneT is one of Europe’s major investors in national and cross-border grid connections on land and at sea, bringing together the Northwest European energy markets and enabling the energy transition. We take every effort to meet the needs of society by being responsible, engaged and connected.

Taking power further
KfW
KfW is one of the world’s leading development banks. With its decades of experience, KfW is committed governments to improving the economic, social and environmental conditions of people worldwide on behalf of federal and state. In 2016 alone, it provided subsidies of €81.0 billion. 44% of these subsidies were allocated to climate and environmental protection measures. In Germany, the KfW Banking Group has offices in Frankfurt, Berlin, Bonn, and Cologne. It is represented in 80 locations worldwide.

Statnett
Statnett is the Norwegian transmission system operator (TSO), and responsible for developing and operating the transmission grid. Statnett is also responsible for balancing electricity production and consumption. The company is developing Norway’s next generation power system to maintain security of supply, facilitate value creation, and facilitate the realization of Norway’s climate objectives. Statnett owns app. 90 per cent of the Norwegian transmission grid. The company has more than 1300 employees and a turnover of app. NOK 6.7 billion (2016).

Source:TenneT