The photovoltaic (PV) panels currently existed on market are laminated plate structures, which are composed of two stiff glass skins and a soft interlayer. Some panels are installed on the buildings and integrated as the components of the structures, such as wall and roof. In different locations, the installations of PV panels are different and the boundary conditions are not always simply supported. In this paper, the bending behaviour of PV panels with various boundary conditions is analysed and the influence of boundary condition is studied carefully. The Kirchhoff theory is adopted to build governing equations of PV panels under static force. A Rayleigh-Rita method is modified to solve the governing equations and calculate the static deformation and stress. Different boundary conditions usually require different assumptions of the deflection function, but a modified general function is developed in here to solve that problem. A theoretical solution is derived out and used to do the numerical calculation. The bending experiments of PV panels with two boundary conditions are used to verify the accuracy of the proposed solutions. Finally, the influence of different boundary condition is stated by comparing the numerical results and some guides for the PV panel installation are proposed.