• Location: Øresund
  • Capacity: 110 MW
  • Installation: 2007
  • Topside Weight: 670 tonnes
  • Water Depth: 4 - 8 meters
  • Substructure: Concrete Gravity Base
  • Detailed Design: Topside
  • Client: Vattenfall


Lillgrund offshore wind farm is the first Swedish wind farm and consists of 48 wind turbines and a connecting substation. It is located approximately 7 kilometers from the Swedish coast, just south of the navigation passage of the Oresund bridge. The offshore substation enables 110 MW of clean energy to be sent ashore near the Swedish city Bunkeflo, corresponding to the energy consumption of 60.000 households. 

Services provided by ISC 

ISC's role in the project was to prepare the concept (FEED), layout arrangement, and the following detailed design of the topside of the substation, including auxiliary systems. Besides that, ISC handled the complete detailed engineering design in place, sea transport, installation, and lift for the topside. Other services provided on the project were fire/safety, process, piping & mechanical, project follow-up, and certification packages for topside for DNV-GL verification. 

General description of the project 

The substation is surrounded by a circular glass façade, which equips the platform with a unique shape and visual impression. This was a client requirement as the offshore wind farm and substation are visible from land and the Oresund Bridge. The Lillgrund topside is designed as a multi-story steel structure with five decks, including a cable deck for cable pulling and cable hang-off. The total weight of the topside system is 670 tons.