On the potential yield of wind turbines on high-rise buildings

Abstract

Urban wind energy has intrigued some investments and applications over the last decade. However, most applications have been unsuccessful, in many cases leaving behind non-rotating wind turbines in the built environment. Research on urban wind energy has also lacked in providing a reliable description of the local flow features small wind turbines are placed in, and the positioning strategy is mostly based on empiricism. This study uses data from a wind tunnel test on the flow pattern above the roof of high-rise buildings to estimate the potential yield of small wind turbines installed in various configurations. The data are collected at a height of 12 m above the flat roof under various wind directions. The capacity factor of a medium-size horizontal axis wind turbine is calculated using power curve data available from the literature. The local wind resource is calculated using the mean wind speed as measured with hot-wire anemometry. The annual energy production of the various configurations is calculated using the climate data available for Firenze (IT) and the orientation of the building with respect to main winds. A rather large variability in the power output of the roof-farm was found for the chosen configuration.