Up to five offshore substations will be installed to collect power from groups of wind turbines before feeding it to shore via the main export cables. The voltage will also be stepped up to increase the efficiency of power transmission in the export cables.

Each offshore substation will typically comprise the following key components:
• Transformers
• Electrical switchgear
• Back-up electrical generator and batteries

The offshore substations would be approximately 25m x 25m x 20m high, standing up to 40m above the level of the sea. Foundations will be similar to those used for the wind turbines.