Issues regarding cost estimation of permanent magnet synchronous generators for mega-watt level wind turbines

Wind turbines with higher power ratings are desired to reduce construction and maintenance time and increase energy yields. Wind turbines with low energy yield and high capital cost present a setback that needs to be overcome. This paper addresses research questions associated with the method by which the energy per cost is calculated. It aims at presenting more accurate calculations based on a combination of methods that take into account lifetime operation of wind turbines. Such calculations are not available for megawatt (MW) level turbines. The proposed method is used to evaluate typical permanent magnet synchronous generators (PMSGs) available in the technical literature. The new method´s outcome is compared to conventional methods used to calculate energy yield per cost. It is shown that lifetime cost calculations come in favour of gearless PMSGs, which have higher material and construction costs.