Damage on the export subsea cable of Anholt offshore wind farm in Denmark has been repaired and the operations on the 400MW wind farm are back on track.
The repairs of the damaged cable took four weeks and two days, after the defect was detected on February 21.
Over the weekend, the last part of the repair was finished, and on Monday the wind turbines were connected to the grid again.
The Danish grid operator, Energinet.dk expects to find out what caused the fault in the cable, however, according to the company, it could take several months to get the answers and how much the repair is going to cost.
“It is a mammoth task to find the fault and replace the broken part of the cable and it can easily take a few months. It only took a little over four weeks and it is not only that we have been lucky with the weather, it is mainly due to our subcontractors NKT and JD Contractors who worked hard to get the cable back in operation as soon as possible,” says Per Hylle , Head of Energinet.dk’s Department for Maintenance Jutland.
Energinet.dk says there are several options that could have caused the fault: a ship anchor might have damaged the cable, there has been an error in the cable as it was originally rolled out over the seabed, or the cable was manufactured with an error.
“DONG Energy, which owns the offshore turbines, should be compensated for the period, the cable has been out of operation, and it has not been possible to sell wind power. It is not yet possible to say how large the amount of compensation will be,” said the company in a statement.
Energinet.dk believes that even though the turbines can produce to the grid, there is still work to be done at sea. Among other things is the cable on the rocky seabed that needs to be flushed down further into the seabed to protect it as much as possible.