A Superconductive Leap for Wind Turbine

Energy CIO Insights | Thursday, December 06, 2018

Superconductors have paved away into the energy industry after the efficient working of wind turbines that replace the magnets with superconducting tape. Wind turbines have the potential to increase markets for wind power, supporting the global transition to continual energy and ultimately lowering electricity costs.

Wind turbine generators use permanent magnets usually neodymium-iron-boron, which is heavy, low cost and easy to machine. The magnets turn the coils to transform the generated magnetic power into electricity. For this, magnets require rare earth metals which are expensive. Generators can be made of superconducting magnets that offer savings in size and weight. EcoSwing is a project that represents an evolution in the application of superconductors for wind turbine generators as a replacement for permanent magnet generators. A ceramic superconducting layer designed with gadolinium-barium-copper oxide (GdBaCuO) is used by the tapes that sit on a steel ribbon for maintaining heavy loaded currents and flexible. The layers of magnesium oxide and silver protect the tape where magnesium oxide acts as a template for crystalline structure, and the outer copper layer provides electrical and thermal stabilization. Marc Dhalle, a Materials Scientist, says that a wind generator of 1MW of power contains a tonne of neodymium in its magnets and the generator uses about 1kg of rare earth material gadolinium which is of less magnitude.

Magne Runde, Energy Researcher at Sintef, in Norway, said that the benefit would be in watts per kilogram of generator weight by using superconductor. People make predictions for an increase in the market for all superconducting power connections like cables, transformers, and generators. Industries don’t show any interest to use unproven technologies, but if they deploy wind turbine superconductor, that might turn as an achievement. In order to achieve superconductive nature, the metal alloys temperature is to be reduced to below 10K. This superconducting technology is often used in hospital MRI scanners that require expensive cooling setups. Magnesium diboride is another phase of superconducting at 39K, which is slightly complicated to cool in wind turbine.

Superconducting composites are the materials have retained industrial interest though no commercialization has occurred yet. The future of superconducting materials can’t be predicted as large +10MW wind turbines were made feasible offshore. Hence, it is unclear whether the future generators will be completely dependent on superconducting technology or there will be a requirement of alternative materials like Magnesium Diboride, high temperature, and low-temperature superconductors for energy-related high power applications.