The first floating windfarm in the world has been introduced to a Norwegian fjord, from where the new turbines will be tugged to their new home off the north-east coast of Scotland.
What used to be just a theoretical concept is now a reality with the potential to unlock the wind energy in marine areas where the waters are too deep to allow fixed-bottom turbines.
The £200m Hywind project was developed by Statoil, Norway’s mostly-state-owned oil company, as it looks to diversify into new areas. Each turbine features a 78-metre underwater ballast, which is then attached to the seabed with mooring cables. The developer says this new technology allows windfarms to be located at sea depths of 100–700 meters, but points out that it could well go deeper. This opens up options in seas and oceans too deep for fixed-bottom turbines, such as the Atlantic and the Mediterranean.
Maintenance is of course more complicated with offshore windfarms, and it only gets more challenging the further out to sea they are, so Shell, the maker of industrial greases like Shell Gadus S2 V100 3, has developed new lubricants that resist degradation for longer and protect bearings from corrosion due to seawater.
While a conventional fixed-bottom windfarm would have probably cost half as much, Statoil predicts that floating windfarms will be cost-competitive by 2030. The technology should be particularly attractive to countries like the US and Japan, where steeply shelved coastlines limit the opportunities for fixed-bottom offshore windfarms.