Building corner modifications are considered useful for enhancing the aerodynamic performance of a single tall building; however, such studies targeted at urban wind energy for compact high-rise building complexes remain scarce. Therefore, a comprehensive CFD analysis of the impacts of building corner modifications on the urban wind energy potential for a compact high-rise building array is performed, including (i) the building corner shape, (ii) the chamfer length, (iii) the corner radius, (iv) the wind turbine type and orientation, and (v) the wind direction. The analysis is based on 3D steady Reynolds-averaged Naiver-Stokes simulations validated with wind-tunnel experiments. The results reveal the notable influence of corner modifications on the mean wind speed, mean wind power density and turbulence intensity. Rounded corners are the most favorable building corner shape yielding a maximum of 365% higher wind power density above the roofs, as compared to sharp corners, with a comparatively noticeable reduction in turbulence intensity. By increasing the chamfer length or corner radius, our study indicates a potential enhancement in wind power density adjacent to high-rise buildings. Our investigations suggest that horizontally-mounted vertical-axis wind turbines may achieve improved performance in wind energy harvesting both in the passages between buildings with rounded corners and above the roofs. These findings highlight the influence of architectural design on urban wind energy potential.