This work presents the quantitative advantage of using a plane mirror as reflector for photovoltaic application. Shade, intermittent nature of solar radiation and dust reduce the total amount of the incident radiation on PV panel and thus reduce its efficiency. Plane mirror is used to increase the incident radiation and thus minimized the effect of the above problems. Experimental measurements are conducted on the performance of a 15 W silicon polycrystalline PV module with mirror reflector and compared with its performance without the mirror. The results obtained show that the plane mirror increased the output power of the PV panel to 20.4W.Thus the use of plane mirror as reflector is recommended to overcome the problem of poor performance due to these problems.