Workers in Bilbao, Spain have begun assembling two giant concrete cylinders to form the base of the country’s first floating offshore wind turbine, due for installation this fall in 85 m of water.

Last month, contractor Ferrovial Construccíon S.A. used two 500-tonne capacity crawler cranes to raise and rotate six vertically cast floater elements and transport them 150 m to an assembly platform to be joined together.

Each roughly 37-m-long floater consists of a cylinder, with diameters varying up to 13.7 m, and two conical ends. Concrete thicknesses are undisclosed. The floaters will lie within a roughly 30-m by 64-m steelwork frame with a single mooring point to support a 2-MW turbine with its axis about 70 m above sea level.

Later this year, Saitec Offshore Technologies, the Spanish lead project developer, plans to install the singly moored floating device at at the Biscay Marine Energy Platform testing center, off the coast of Armintza in northern Spain.

Working with Germany's RWE Renewables, Saitec will then trial the DemoSATH prototype for two years.

Project cost was not dfsclosed.