The fabrication of the Sofia HVDC offshore converter platform (OCP) is progressing steadily at Sembcorp Marine Ltd’s yard in Batam, Indonesia

March 17, 2022 | Renewables | Energy Facts Staff Writer | 2min

Most Powerful and Remote Offshore Converter Platform ever built.

One of the largest offshore wind platforms in the world.

We are proud to announce that Iv-Offshore & Energy has been awarded the contract with Sembcorp Marine Integrated Yard Pte Ltd (SMIY) to provide multi-disciplinary detailed engineering and design for the Sofia high voltage direct current (HVDC) offshore converter station, one of the largest offshore wind platforms in the world. The scope will include a topside weight of 10,000 tonne and a jacket weight of 7,000 tonne, the utility system and the procurement of the topside auxiliary equipment.

Dogger Bank

Sofia is 100% owned by RWE Renewables, one of the world’s leading players in offshore wind, and its  HVDC converter station will be installed in the shallow-central area of the North Sea known as Dogger Bank. The wind farm will have a total capacity of 1.4 GW and will comprise100 wind turbines. Together, these wind turbines will provide enough sustainable energy to power the equivalent of 1.2 million British homes.

SMIY and Iv-Offshore & Energy began the early design works for the project in July 2020; the Sofia project contract was signed in June 2021. Iv-Offshore & Energy will assist SMIY with the purchase of all auxiliary equipment and as a partner of SMIY, Iv-Offshore & Energy is at the helm of the engineering and platform system integration. GE Renewable Energy’s Grid Solutions, being partner to Sembcorp Marine, will fully supply the high voltage direct current (HVDC) transmission system.

A piece of progressive innovation

Sofia Offshore Wind Farm will be sited 195 km from the nearest point on the UK’s North East coast. Covering a total of 593 km2, Sofia will comprise an inter-array cable network nearly 370 kilometres (230 miles) in length that will transport the generated electricity from the wind turbines to the platform. The Sofia platform will then convert this electricity, from a voltage of 66 kilovolts (kV) alternating current, to 320 kV direct current and transport the power to the onshore converter station in Teesside. From there a further two kilometres of cables will transmit the power to the existing National Grid substation in Lackenby.

The Sofia Offshore Converter Platform is a piece of progressive innovation, with a focus on safe operation and maintenance. The smart and robust solutions have resulted in a compact integrated design of the HDVC and auxiliary systems, while the optimised cooling system ensures high energy efficiency.