Direct drive wind turbine generators are a popular powertrain configuration for offshore installations due to the high reliability and efficiency that results from the lack of gearbox. However, their high-torque operation results in very large, heavy, and expensive machines that utilize several tonnes of high-grade rare-earth permanent magnet material. Fergus’s research is centred around innovative concepts for reducing the cost of direct drive generators, such as filling the air-gap region with magnetically permeable ferrofluid.