Floating: the trajectory of cost reduction by Kate Freeman

Currently only a small proportion of the seabed around the globe is suitable for offshore wind development due to current fixed foundation requirements of water depth and sea bed condition regardless of other constraints such as shipping lanes and nature reserves. Floating foundations can be deployed in much deeper water across a wider range of sea bed conditions. Floating foundations are therefore a potentially vital key for offshore wind to become a truly global industry.

The early deployments of floating technology are providing encouraging results. For example, the  capacity factors for the Hywind project in Scotland have been better than expected. But floating costs need to fall much more dramatically in order for it to be considered ready for wider commercial roll-out. Innovation has a vital role to play in reducing costs. Following extensive industry engagement and in collaboration with InnoEnergy, we recently examined how innovation could reduce the cost of energy from floating offshore wind farms up to 2030. The resultant report can be downloaded for free here: ‘http://www.innoenergy.com/offshorewind.report’ (cut and paste address into your browser).

Some of the cost reductions, such as turbine rating, turbine design and blade improvements, will be just as applicable to fixed foundation projects as floating. Our work suggests that around two-thirds of the total reduction in floating costs to 2030 will be due to these ‘shared’ cost savings. These innovations would give no “competitive” advantage to floating but would be vital in helping floating compete with other forms of generation such as CCGT.

Improvements in the design and manufacture of support structures and mooring can provide floating foundations cost reductions beyond those innovations shared with fixed, as can improvements is floating-specific array cabling. Improvements in installation and OMS (Operation, maintenance and service) will also help nudge costs down, but by smaller amounts. As experience grows and costs begin to fall, a virtuous circle will develop as projects get bigger, learning increases, economies of scale kick-in and transmission systems become more effective. This in turn will reduce the perceived risk of using floating foundations which will lower financing costs.

Cost reduction and innovations in floating foundation technology will happen over the coming years. They key challenge is whether they will be realised and spread quickly enough to attract investment, supply chain development and further innovation for floating offshore wind farms to develop as a commercially viable option for electricity generation.


Kate Freeman