The Energy, Materials and Systems (EMS) chair of the University of Twente Faculty of Applied Sciences is receiving a grant of two million euros within a European project for the development of a superconducting generator for a new generation of wind turbines. The kick-off is on May 27th in Brussels. By incorporating superconducting generators, it will eventually be possible to produce wind turbines that are considerably lighter and hence with reduced cost. In 2018, the generator will be built into an existing 3.6-megawatt wind turbine in the Danish Thyborøn.
This concerns the Horizon 2020 'EcoSwing' project that is coordinated by the Danish company Envision. The budget for the entire project is 13 million euros: 3 million euros from the participating companies and 10 million euros from the EU. The aim of the project is to develop the world's first superconducting generator that is incorporated in a wind turbine. The generator will be installed in 2018 in the very latest 3.6-megawatt wind turbine, this being sufficient to supply about a thousand households. The entire system is then intensively tested for one year. The kick-off of the project and the first meeting of the General Assembly are on May 27th in Brussels.
The main advantage of the superconducting generator is that it is forty percent lighter than conventional generators. As a result, the turbine's nacelle can be made 25 percent lighter, reducing also the size and weight of the support structure. Due to material savings, the cost can be greatly reduced over time. Another advantage is that the new technology is much less dependent on expensive rare earth metals (a group of heavy chemical elements that are mined mainly in China). Thus in contrast with conventional generators, the superconducting generator, for example, does not use any of the expensive material neodymium. Instead it uses a much smaller amount of yttrium (about a hundred times less).
Conventional large wind turbines work in the same way as a bicycle dynamo, but scaled up. A rotor with permanent magnets rotates within a series of coils. This causes the coils to experience an alternating magnetic field, which generates electric power. With a superconducting generator, you replace the permanent magnets with superconducting coils. These make use of the phenomenon that the resistance of some materials completely disappears at extremely low temperatures (in this case -1800C). As a result, a thousand times more current can flow through them, generating a magnetic field up to thirty times stronger than permanent magnets or copper coils.
UT's EMS chair will use its many years of experience with superconducting magnets in the design and testing of the rotor coils. Within EcoSwing, the group also takes care of the rotor assembly. That assembly of the approximately twenty-tonne rotor with a diameter of five meters is an enormous task, for which Dutch industry will also be deployed. The vital cooling of the coils is one of the tasks of the UT group. The EcoSwing consortium consists of nine partners. In addition to the UT and Envision, there are seven companies: five from Germany, one from France and one from the UK.