COBRAcable back in operation

© TenneT

The COBRAcable, which connects the Dutch and Danish electricity networks, is back in operation again after a failure in the cable since the end of September 2020. The interconnector is designed in such a way as to enable the connection of an offshore wind farm at a later stage.

The COBRAcable is a 325 km long 320 kV, 700 MW HVDC submarine power cable pair between Eemshaven, the Netherlands and Endrup near Esbjerg, Denmark. It enables the import and export of renewable electricity between the two countries and thus improve the European transmission grid. The connection has been designed in such a way as to enable the connection of an offshore wind farm at a later stage.The cable is jointly owned by Energinet.dk and TenneT. The connection was officially inaugurated in November 2019.

The cable transferred the first power in September 2019. At the end of September 2020, a failure was detected which put the interconnection out of operation for several months to perform repair activities. inauguration

Repair work offshore
The last few weeks, repair work has been done at sea. The cable was cut at a depth of 40 metres on the seabed and lifted. On both sides of the cut cable, the cable was measured 200 metres long to find the exact fault location. The piece of cable where the fault has been located was removed. A new piece of cable has been installed and reconnected to the cable.

The last few days, the cable has been successfully tested and laid back, buried two metres deep in the seabed. The interconnection is back in operation since today, TenneT reported.