Transmission operator Energinet.dk replaced part of the project's export cable following a fault in February. The project returned to operation in March.
From tests on the broken cable, Energinet has decided to replace two sections of the link. The results show a risk of further faults in a four-kilometre stretch of the cable from the substation, said Energinet.
There is also a risk of further faults at a 400-metre section of the submarine cable to where it makes landfall at Grena, east Denmark.
Energinet said the work is scheduled to take place over five to six weeks in September and October, weather permitting.
Under Danish legislation, Dong will receive compensation for lost production. In its H1 results, announced yesterday, the utility said its energy production was affected by the downtime in February.
The project suffered another outage in September 2014 following a short circuit of the onshore cable. Production was interrupted for seven days, forcing Energinet to pay Dong more than DKK 9 million (€1.2 million) in compensation.
Anholt, the largest wind development in Danish waters, came online in 2013, It is located 15 kilometres off the north east coast of the country and features 111 Siemens 3.6MW turbines.
