A vertical axis wind turbine has been designed to electrify a novel kind of telecommunication tower. This paper presents the design of a generator for this purpose. The generator is a permanent magnet generator rated at 10 kW. It has an unusually large diameter to fit on the outside of the telecommunication tower. The generator has been designed by using a two-dimensional FEM model. Simulations show that the generator has high efficiency through the whole operational interval. Furthermore, the generator has a high overload capability enabling electric control of the turbine. The generator has been built and the design shown feasible. Preliminary experimental results show that the induced voltage is lower than expected from simulations indicating insufficient modelling of three-dimensional effects, which are particularly large in a generator with these unusual dimensions.