TenneT Nears Final Cable Installation for 6 GW Rotterdam Offshore Wind Link

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TenneT expects the remaining underground cables for three offshore wind connections at Rotterdam’s Maasvlakte to be installed in early 2027, bringing a combined 6 gigawatts of planned transmission capacity closer to completion.

The Dutch state-owned transmission system operator said the onshore works have entered their final phase. The cables will serve IJmuiden Ver Beta, IJmuiden Ver Gamma and Nederwiek 2, each designed to bring approximately 2 GW of offshore wind power ashore.

The connections will feed electricity into the Dutch high-voltage network through the Amaliahaven substation, supplying routes inland and new grid connections in the Rotterdam port area. The milestone concerns cable installation rather than the start of electricity deliveries from the offshore wind farms.

The final horizontal drilling operation is located near the Coloradoviaduct on the N15, between the Amaliahaven high-voltage substation and the IJmuiden Ver Beta converter station.

The operation completes the installation of underground protective ducts. Contractors will subsequently pull electricity cables through those ducts, with the remaining installation work expected in the opening months of 2027.

Preparations for the final cable sections are under way at Amaliahaven and the IJmuiden Ver Beta converter station, according to TenneT.

Elsewhere along the route, construction has advanced to joining individual cable sections. Crews are connecting them in underground chambers known as joint bays to create continuous electrical links, while cables are also being routed into the stations.

Patrick Bakelaar, stakeholder manager for contractor NRG, said the separate parts of the project were coming together. Once the remaining cables are installed and connected, the main installation work will be largely complete, allowing teams to clear temporary construction sites and restore the surrounding areas.

Electricity from the offshore wind farms will reach Maasvlakte as direct current. Onshore converter stations will change it into alternating current for transmission through the national electricity network.

The three connections form an electricity corridor between North Sea generation sites and consumers on land, including industrial users in the Rotterdam port area.

Their combined 6 GW capacity is comparable to the generating capacity of six large gas-fired power stations, according to TenneT. That comparison describes capacity rather than equivalent annual electricity production, which depends on operating conditions.

For port and industrial stakeholders, the onshore cable works are one part of a wider construction programme involving offshore platforms, subsea cables, converter stations and connections to the national grid.

The Maasvlakte projects form part of TenneT’s 2 GW programme for offshore grid infrastructure in the Dutch and German sectors of the North Sea.

A consortium comprising GE Vernova and Seatrium holds contracts covering the high-voltage direct-current systems for IJmuiden Ver Beta, IJmuiden Ver Gamma and Nederwiek 2.

Those projects sit within a broader procurement programme launched in 2023, when TenneT signed multiyear agreements worth approximately €23 billion for eleven offshore grid connections, each with a capacity of 2 GW.

At Maasvlakte, the next steps are to pull in the remaining land cables, complete the cable joints and restore the temporary work sites.