The COBRA cable is one of Denmark's important electricity connections abroad; the one to the Netherlands. Last Thursday, the connection celebrated its 5th anniversary. Since 2019, the Dutch and Danish high-voltage grids have been directly connected to each other via a submarine direct current high-voltage connection. The interconnector has made direct electricity trading between the Danish and Dutch markets possible for the first time.
Construction
In April 2009, TenneT and the Danish Energinet.dk signed a cooperation agreement for the construction of a new high-voltage direct current submarine connection to directly connect the electricity grids of the Netherlands and Denmark: the COBRAcable project. COBRA is an abbreviation of COpenhagen BRussels Amsterdam. The European Commission supported the COBRA project with 86.5 million euros from the 'European Energy Programme for Recovery'.
The decision to lay the cable was made in September 2014. Part of the work was the construction of a new, 325-kilometer-long connection between Endrup in Denmark and Eemshaven in the Netherlands. (See the video below.)
The work was put out to tender in early 2016. Siemens AG supplied the converter stations for both sides of the connection, and the DC cable was supplied by Italy's Prysmian , one of the world's largest cable suppliers. The connection was completed in early 2019. The official opening took place on November 4, 2029, both in Eemshaven (see main photo) and in Endrup, Denmark.
Construction of the connection began in January 2017 with the driving of the first pile for the Dutch conversion station in Eemshaven. The cable landed in the Netherlands in November 2018.
Capacity
The approximately 325-kilometre cable has a capacity of 700 MW. Since 11 September 2019, the 325-km-long submarine cable has exported 12.5 TWh of electricity, while almost 7 TWh has flowed the other way. The cable structurally makes Dutch capacity available to the Danish electricity grid and vice versa.
The COBRAcable is an initiative of TenneT and the Danish electricity and gas grid operator Energinet. The cable runs from Eemshaven (Netherlands) via Germany to Endrup (Denmark). Two converter stations on land, one in the Netherlands (Eemshaven) and one in Denmark (Endrup), convert alternating current into direct current. This makes it possible to transport electricity over long distances without major losses. The converters also convert the direct current back into alternating current; electricity grids operate on the basis of alternating current. (Also read: What is HVDC and what are the advantages? - NedZero )
Interconnection
The purpose of the cable is to transport sustainable electricity, generated by wind farms, among other things. The Netherlands can import more sustainable electricity via the cable, especially wind from Denmark. For Denmark, guaranteeing security of supply is of great importance. The cable makes Dutch capacity structurally available for the Danish electricity grid and vice versa.
Furthermore, the cable connection is designed in such a way that it is possible to connect an offshore wind farm at a later stage. As a result, the cable contributes to the realisation of a sustainable international energy landscape, an aim of the European Union.
The interconnector enables direct electricity trading between the Danish and Dutch markets for the first time.
Other connections
In addition to the connection with Denmark, the Netherlands also has major electricity connections with Norway and England. These are the NorNed cable and the BritNed cable respectively.
The NorNed cable is a 580 km long direct current high-voltage cable across the North Sea floor between Norway and the Netherlands. This cable came into use in May 2008. The connection is operated by TenneT and the Norwegian Statnett .
The BritNed cable is also a high-voltage direct current cable. It runs across the North Sea floor between the Netherlands and Great Britain. (See below.) The project was developed by NLink, a subsidiary of TenneT, and National Grid. BritNed is the second overseas high-voltage cable connecting Great Britain to the European continent. The first connection was with France in 1961, upgraded in 1986.
