The port sits in an area regularly hit by Biscay storms, which over the years have taken their toll of the piers and often made it hazardous for vessels entering the harbour, so some kind of mitigation scheme was necessary. However, it wasn’t easy to settle on a plan, and no fewer than 17 different alternatives were examined.
Faced, finally, with a project that involved a detached breakwater approximately 440m in length with a pierhead at either end, the authorities had the imaginative idea of turning a necessity into an advantage by incorporating an ocean energy generation plant.
Ente Vasco de la Energía, the Basque energy board, and the Department of Public Works co-operated on the project, which utilises Oscillating Water Column (OWC) technology. The Voith Hydro OWC devices are simple and non-disruptive, as the arrangement consists of a hollow structure, open to the sea below water level with a hole at the top of the chamber. When the wave comes in, the water enters the chamber, compressing the air inside which is pushed out at high pressure through an opening at the top. This pressurised air turns the turbine – and the fact that it is the air and not the water that moves the turbine considerably extends the service life of the equipment.
The 16 power units will provide an output of 300 kW in total, electricity sufficient for around 250 homes.
