Transmission system operator TenneT has awarded a contract to Alstom for the DolWin3 offshore transmission project, which connects several North Sea wind farms to the mainland electric grid and has an investment volume of more than 1 billion euros.
As the general contractor for TenneT, Alstom will supply and construct both the onshore and offshore converter stations, as well as the connecting cable systems, for DolWin3. The project will use direct-current (DC) technology to deliver the energy generated at sea down an 83 km sea cable to the mainland.
From the coast, the wind power will then be transported another 79 km via an underground cable to the converter station in Dorpen/West in Lower Saxony, Germany.
In addition, Alstom has been awarded a five-year service contract covering the complete offshore converter station and platform, as well as the onshore converter system. The contract includes inspection, preventive and corrective maintenance, refurbishment and repair, spare-parts management and a technology support line.
Alstom will work with platform constructor Nordic Yards and cable supplier Prysmian for the project.
DolWin3 is the eighth grid-connection project to be implemented by TenneT using DC technology. Together with three projects based on alternating-current technology, the grid operator will deliver a total of 6.2 GW of offshore wind energy to the mainland.
The DolWin3 project will be the third grid connection in the DolWin wind farm cluster in the southwestern region of the North Sea and will offer a capacity of 900 MW. The project will be completed in 2017.