Due to the negative correlation between PV cell temperature and its efficiency, study on convection heat transfer from PV panel under real windy condition seems essential. Then a 3D numerical model has been established to investigate the impact of PV tilt angle, wind condition and different heat flux boundary conditions. To reveal the influence of photoelectric conversion characteristic on convection heat transfer, two boundary conditions, i.e., constant heat flux and heat flux varying with temperature are adopted and compared. Velocity vector field, temperature and velocity contours are also provided for detailed analysis. Within the studied range of tilt angle alpha, it is interesting to find there exists a minimum Nu(c), and the corresponding alpha shifts to a larger value with increasing wind velocity. As wind direction varies, a decrease in Nu, is discovered at first, and then a rising tendency is followed. In addition, as wind velocity is relatively lower, higher heat flux enhances Nu(c) at random alpha, especially for the case of alpha >= 45 degrees Finally, a novel empirical correlation about convection Nusselt number incorporating the factors of tilt angle, wind direction and wind velocity is put forward. (C) 2017 Elsevier Ltd. All rights reserved.