Solar photovoltaic (PV) systems are used worldwide for clean production of electricity. Photovoltaic simulation tool serve to predict the amount of energy generated by the PV solar array structure. This paper presents the photovoltaic system installed on the rooftop of the G.D. Naidu Block at Vellore Institute of Technology (Vellore, India). A novel PV plant design is developed here in order to improve the energetic efficiency of an existing PV system. The effectiveness of proposed design is evaluated over an entire year using the PVsyst v6.70 software, which works on accurate plant specifications. For this purpose, Metronome 7.1 weather data sets of ambient temperature and radiation from PVsyst database are used for the investigation. The cost of the proposed PV system and the required payback period are analyzed as well. Simulation results demonstrate the superiority of the proposed PV system design over the existing one in terms of the amount of electric energy injected in the grid, energy conversion efficiency, and reductions in CO2/SO2/NO emissions. Performance ratio of proposed design (Design 2) is 0.791 whereas the existing design (Design 1) is only 0.704. Design 2 provides 40 MWh more energy to grid than Design 1 due to reducing shading losses. The daily system energy generated for Design 2 is maximum (in particular, 26–29% higher than for Design 1) between March and May, when the sun is brightest and directly above our head. Shading analysis carried out for both designs revealed that the existing Design 1 has more shading loss while the proposed Design 2 may reduce this loss by about 11–13%, which results in a better efficiency of energy production. The article also documents significant emission reduction and cost analysis calculation for the proposed Design 2. © 2021