RWE appoints contractors for Sofia electrical transmission system

A consortium of GE Renewable Energy’s Grid Solutions and Sembcorp Marine is set to supply the system for Sofia, one of the world’s largest offshore wind projects.

RWE Renewables chief operating officer offshore wind Sven Utermöhlen said, “With the innovative technology solutions we have chosen for Sofia we have prepared the ground for the realisation of what is one of our largest development projects.

“We are keen to support the growth of onshore and offshore wind energy in UK, one of our core markets in Europe. The choice of GE’s Grid Solutions and Sembcorp Marine for the supply of the electrical system is an important statement of our commitment to grow our renewables portfolio in the UK and reflects our ambition to strive for continuous innovation in the development, construction and operation of our offshore windfarms.”

As the consortium leader, GE’s Grid Solutions will be responsible for the engineering, procurement, construction and installation of two HVDC converter stations capable of transmitting 1.4 GW of power at 320 kV. Innovative converter modules and a new high-tech control system have been deployed for Sofia.

The offshore converter station will be one of the most powerful ever fabricated and will be installed at a point 220 km from shore, so will also be the most remote.

The offshore converter platform will be built and installed by Sembcorp Marine. At the heart of the windfarm, it will have a 10,000-tonne topside attached to a jacket foundation piled into the seabed. The onshore converter station will convert the electricity generated by the windfarm to 400 kV before it enters the national grid.

GE Grid Solutions and Sembcorp Marine are starting early design works in July 2020, with the full contract subject to the project’s final investment decision, due in Q1 2021.

The HVDC transmission system represents Sofia’s second-largest contract and will include the design, manufacture, installation, commissioning and maintenance of the offshore converter platform and the onshore converter station, including all ancillary equipment.

Construction of the windfarm is due to begin onshore at its Teesside converter station site early next year, with offshore construction expected to get underway in 2023.

Earlier this year, RWE signed a preferred supplier agreement with Siemens Gamesa Renewable Energy for 100 of its SG 14-222 DD offshore wind turbines, a 14-MW design.