Floating windfarms have arrived

Offshore wind farms are nothing new. The very first offshore wind farm was commissioned in Denmark back in 1991. But until recently, the construction and stable anchoring of offshore turbines, which involves an average of 150 – 250 tonnes of structural steel, could only been achieved in relatively shallow water – to a maximum depth of 50 metres.

Permission granted for the world’s biggest floating wind farm

The approval last year of the world’s largest floating wind farm off the coast of Scotland, marks a serious development for wind energy. A number of floating wind farms trials have been successfully constructed and tested around the world, but the 30 Megawatt, Hywind project, to be built and operated by Norwegian energy company, Statoil is the biggest and is expected to generate enough renewable energy to power 20,000 households.

Consisting of five 6 Megawatt floating Siemens turbines, the wind farm will be located 25 kilometres off the coast of the Scottish town of Peterhead in waters reaching a depth of 100m. The project is in its early stages, with energy expected to be generated in 2017.

The key to success is the ballasted steel cylinder

The key development that has suddenly made floating wind farms commercially viable is the success of a ballasted steel cylinder structure, which in trial scenarios has proved that it exceeds marine stability criteria while securely supporting a wind turbine. The ballasted steel cylinder is independent of the wind turbine. Any make or model of wind turbine would work with the floating cylinder – it simply has to comply with weight requirements. The technology built into the floating steel cylinder along with its anchoring system is what is crucial to floating wind farm success. Statoil’s Hywind concept uses a mooring system that consists of three mooring lines attached to anchors, which are customised to the sea bed conditions.

Benefits of offshore wind farms

Building wind farms on shore is certainly easier, but there are big benefits to creating offshore wind farms and if these wind farms can also be constructed in deep water, this sustainable energy source will become a more commercially viable. Benefits of constructing wind farms offshore include:

• There’s more wind offshore, more energy can be generated.
• The wind turbines can be larger. The steel blades used in Siemens 6MW wind turbines are 45m long and the rotor itself has a diameter of 154m. Wind farms that use these super-size turbines are able to produce more energy from fewer turbines.
• The logistics of installing the turbines is actually easier offshore. Large ships can transport wind turbine components such as tower sections, nacelles and steel blades more easily than trains and trucks.

The search for the perfect, commercially viable and completely sustainable source of energy will continue and the recent developments in floating offshore wind farms are very promising. Regardless of which sustainable energy source is being generated, the construction of large-scale solar and wind farms still rely on a number of core components made from steel.

At ShapeCUT, we’re able to meet our customers’ highly specific design requirements due to our range of steel cutting services and our in-house range of stocked steel plate, which is the largest on the market. Our Same Day Service means we can meet even the toughest deadlines. Regardless of the business you’re in, if you require a custom component fabricated from steel, contact ShapeCUT to see how we can help.