Materials use in electricity generators in wind turbines – state-of-the-art and future specifications

The European Strategic Energy Technology Plan, adopted by the European Union in 2008, is a first step to establish an energy technology policy for Europe and to support the 2020 energy and climate change targets from the technology development point of view. One of its initiatives is to assess the characteristics of the materials that will be needed in order to achieve the 2020 targets, in terms both of amounts of materials and their technical specifications, along with the way to get there for the latter. The Materials Initiative was created to foster a roadmap which is based on a scientific assessment of the current situation. This paper presents the work of the author in the (wind turbine) electricity generator part of that assessment, it includes the aspects of technology and system state-of-the-art; material supply status; on-going research and players; materials specification targets for 2020/2030 and beyond. The assessment found that the performance of permanent magnets is the single item potentially to provide the most significant improvement in component specification, but that in order to achieve this perhaps new chemical components –based on rare earths, as currently, or not-will be necessary in order to achieve these high-performance magnets. The search for these new materials is stimulated by the current dependency of the world in a nearly-monopolistic supplier of rare earth elements. The assessment also concluded that the improvement of materials specifications is challenging but achievable in most areas, and a crucial aspect for the necessary cost reductions in wind energy production.