German offshore wind farm developer RWE has selected two preferred suppliers for the electrical transmission system and entered into early works agreements in relation to the construction of the Thor offshore wind farm in Denmark.
With a planned capacity of 1,000 megawatts (MW) Thor will be Denmark’s largest offshore wind farm to date. The wind farm will be built off the Danish west coast - approximately 22 kilometers from the port of Thorsminde. RWE in late 2021 won the rights to build Thor via a lottery system
RWE said Friday it had selected Siemens Energy as the preferred supplier for the design, construction and installation of the onshore high-voltage substation.
The work will be carried out by the company's Offshore Center of Competence, located in Ballerup, Denmark. HSM Offshore Energy has been selected as preferred supplier for the engineering, procurement, construction, installation, and commissioning of the offshore high-voltage substation and its jacket foundation.
To connect the wind farm to the Danish grid, RWE will build two new substations – one at sea and one on land. The substation at sea is the nerve center of the wind farm: the electricity produced by the individual wind turbines is collected here and transformed to transmission-level voltage, RWE said.
The electricity will be transported through export cables to the newly built onshore substation Volder Søndervang, which is located close to the coastline and the adjacent grid connection point of the Danish grid operator, Energinet. A corresponding grid connection agreement has already been signed between RWE and Energinet in the spring.
RWE has purchased the land in the municipality of Lemvig where the onshore substation will be located and has carried out ground conditions and archaeological surveys.
Siemens Energy will start design works, followed by the procurement of main equipment and the submission of permit applications.
"It is expected that construction activities can be kicked-off on site in spring 2023. Siemens Energy is planning to carry out the civil engineering and construction works together with MT Højgaard Danmark, one of Denmark’s leading companies for large-scale building and infrastructure projects," RWE said.
HSM Offshore Energy together with its engineering subcontractor Iv-Offshore & Energy has already delivered several offshore substations for Energinet in the Danish North Sea.
"Based on its experience and technical know-how they created a highly efficient design for RWE’s Thor substation and its foundation. This reduces the use of structural steel and the energy needed during manufacturing – with steel sourcing and fabrication in Europe. Installation of the jacket foundation in water depth of up to 27 meters and installation of the substation are expected to take place in 2025 – followed by the commissioning and testing of the offshore substation in 2026," RWE said.
Once fully operational, which is planned to be no later than 2027, RWE’s Thor wind farm would be capable of producing enough green electricity to supply the equivalent of more than one million Danish households.
For the operation and maintenance of the wind farm RWE will set-up a service base at the port of Thorsminde. RWE intends to contribute to the local economy and community by creating up to 60 permanent jobs in the long run, the company said.
This includes technicians, engineers, nautical personnel as well as crew for the service vessels. It is expected that the new service station will be fully operational from 2026 onwards. RWE plans to support its wind farm for at least 30 years from this port.
RWE is not a newcomer to the Danish offshore wind sector as it is already operating the Danish Rødsand 2 offshore wind farm, which is located south of the Danish island Lolland, approximately 10 kilometers southeast of Rødbyhavn. The wind farm has an installed capacity of 207 MW (RWE share: 20%) and has been in operation since 2010.