Offshore transformer platform in the Baltic Sea - Red Sand II

RedSand-II, 3D-model transformerplatform 
 Photo: COWI.
The public-owned company Energinet.dk, which owns the infrastructure for the supply of electricity and gas in Denmark, has awarded COWI the contract to design a transformer platform to be located in the Baltic Sea a couple of kilometres offshore of south eastern Denmark.

The platform will be placed at a depth of six metres on a so-called "gravity-based" foundation, which retains its stability on the sea bed in all weather conditions by virtue of its own weight.

Red Sand II

The new windmill park Red Sand II will comprise 90 offshore wind turbines with a total output of 200 MW, enough to supply 200,000 households for a whole year. Red Sand II also offers the opportunity to build three trial wind turbines with a capacity of 15 MW in total.

The transformer platform will collect electricity from these wind turbines and transform it from 33 kV to 132 kV for transferral via a powerful marine subsea cable to the shore, benefiting domestic consumers and companies alike.

COWI’s services

COWI designs the platform topside and its concrete foundation. The platform itself houses the main transformer with associated cables and panels, internal power supply, an emergency generator, a fire-fighting unit, a workshop and monitoring and control system. The whole operation will be controlled and monitored from the shore.

The platform topside weights approximately 800 tonnes, not counting its concrete foundation. The transformer alone weighs 280 tonnes. The ground plan will be 30 m x 16 m.

LAST UPDATED: 19.09.2017