Scaldis has installed the 2000-tonne offshore substation topside on the 400MW Rampion offshore wind farm, some 14 kilometres off the Sussex coast.
The topside was installed by the heavy lift crane-vessel Rambiz.
The structure at the Rampion wind farm will eventually transform the electricity generated by the planned 116 turbines at the site from 33kV up to 150kV.
This will allow the facility to provide enough electricity to supply almost 347,000 homes a year, equivalent to around half the homes in Sussex.
After taking approximately two years to design and build, the offshore substation was transported 500 miles by sea from where it was made in Scotland to Southampton, before being towed out to its final location.
The turbine installation began last month and to date, eight are fully installed.
The GBP 1.3 billion Rampion offshore wind farm project is owned by E.ON, the UK Green Investment Bank plc and Canadian energy company Enbridge.
The project is due to be completed and operational in 2018.