Urban wind power shows a great potential and plays a significant role for a sustainable city. As a fundamental issue, the interaction between the wind-turbine wake and a building array is studied here via large eddy simulation. The standard actuator disc model is used to model the wind turbine, and 16 cube-shaped buildings are used to represent the urban district. It is found that due to the blocking effect of the downstream urban district, a high-pressure region is formed upstream, which dramatically changes the trajectory of the wind-turbine wake and results in a fast wake recovery. In addition, the wind-turbine wake suppresses the vertical momentum flux and thereby reduces the wind speed in the streamwise streets. At the top region of the urban block below the trajectory of the turbine wake, the turbulence intensity substantially increases at the entrance region of the building array, while the overall turbulence intensity is considerably reduced at the bottom of the block. (C) 2020 Elsevier Ltd. All rights reserved.