Several floating wind turbines have been installed in recent years, with operational turbines in Norway, Japan and Portugal.
Floating turbines have several benefits over their conventional counter-parts – firstly, they are more economically efficient, as onshore assembly and the ability to tow them into place reduces the need for costly heavy-lift vessels or specialized wind turbine installation vessels.
Secondly, floating turbines can be installed in deeper water (often further offshore) alleviating concerns of visibility from the coast. Thirdly, greater offshore distance increases wind exposure, resulting in comparatively higher electricity generation.
We ask, however, whether floating wind turbines will be utilized globally as governments seek to meet renewable energy quotas?
Successful installations provide hope to those championing floating wind turbines. The WindFloat project in Portugal, is a particularly interesting example – currently supporting a 2MW turbine, 6km from shore.
WindFloat refers to the floating support structure, which allows wind turbines to be installed in water depths exceeding 40m. The structure comprises three columns, each is fitted with water entrapment plates at the base, resulting in improved motion performance and allowing the use of conventional wind turbines atop the structure.
WindFloat has been operational for three years and by end-2014 had delivered 12GWh of renewable electricity to the Portuguese grid, with no issues to date. Other successful projects include Hywind and Sway prototype projects in Norway, and a number of pilot projects in Japan.
Douglas Westwood’s Offshore Wind Database shows at least nine floating projects are likely to come online by 2020, totaling 225MW – a further six projects in the pipeline provide upside potential. However, these technologies require significant investment and cooperation (WindFloat involved 60 suppliers), and each project is unique – standardization is key if floating offshore wind turbines are to be rolled out on a large scale.
However, with some predictions that floating wind turbines could cut offshore wind costs in half, there are huge incentives for increased use of the technology.