Improving sustainability and resilience of future cities. Positioning of wind turbines within the urban environment

Wind Energy technology represents the most technically advanced and diffused renewable resource. The willingness to foster its economical profitability has brought to new uses of the technology, especially in unconventional locations. In particular, the Urban environment is promising in reducing the costs associated e.g. to the large infrastructure wind farms require. However, several technical and non-technical issues remain unsolved, spacing from the understanding of the actual wind resource available to the actual response of wind turbines. This contributes to foment the lack of confidence in wind energy and its societal acceptance. The lack of knowledge is an issue that adds sharply to NIMBYism rhetoric mechanisms. In this work, various possibilities and limits of Urban Wind Energy are introduced, with a focus on the urban wind resource. A suitable high-rise building configuration is taken as a reference and simulated using CFD, to discuss the possible strategies in optimising the positioning of wind turbines, which strongly depend on their relationship with the built environment. The challenges related to such a methodology are also introduced, with special reference to the necessity of accurately modelling the signature turbulence for the reliable aerodynamic design of the new generation of small and medium size wind turbines.