Silicon photovoltaic modules are widely used in solar power plants worldwide, but their efficiency is of concern due to intermittent nature of solar radiation and non-optimum inclination of PV panels. The PV system power potential is enhanced using reflectors installed at optimum tilt angle. In this study performance of a PV-mirror reflector system installed at respective optimum tilt angles, is evaluated for a two-year period. The average power enhancement of PV-reflector system is found to be 10-19.84% in summers and 10-13.23% in winters. A new model is developed to determine reflector optimum tilt angles and the results are validated experimentally. The reflector optimum tilt angles are determined to be 40(0) for summer and 15(0) for winter for Hamirpur location, Himachal Pradesh, India. The error in the predicted and experimental optimum tilt angles is found to be 12.5%. The PV module temperature rise due to reflector is found small so the effect on PV efficiency is not substantial for this location. The present study is of relevance for PV power plants to improve land use efficiency and to reduce the cost of energy generation for any location worldwide. Further follow up research areas are also identified. (C) 2020 Elsevier Ltd. All rights reserved.