Transmission system operator TenneT awarded the DolWin3 offshore project to Alstom. This project connects the North Sea wind farms to the mainland supergrid and has an investment volume of more than $1.3 billion.
With this project, TenneT will be able to supply more than 6,000 MW of clean energy from the North Sea. About $9.1 billion will be invested in this energy turnaround.
DolWin3 is the eighth grid connection project to be implemented by TenneT using direct current technology. Together with three projects based on AC current technology, the transmission system operator responsible for the North Sea will then deliver a total of around 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.
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 technology (with Voltage Source Converters (VSC); ±320 kV, 900 MW) to deliver the energy generated at sea down an 51 miles sea cable to the mainland. From the coast, the wind power will then be transported a further 49 miles via and underground cable to the converter station in Dàƒ¶rpen/West in Lower Saxony (Germany). The grid connection will be supplied as a turnkey solution by Alstom.
Together with the turnkey contract, Alstom won 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 has chosen the most experienced partners on the market to complete this project, working with platform constructor Nordic Yards and cable supplier Prysmian. Both companies are highly experienced in the field of offshore work.
TenneT is a transmission grid operator for electricity in Europe with around 20,000 of high-voltage and extra-high-voltage lines and 36 million end users in the Netherlands and Germany.