Techno-economic and environmental feasibility assessment of a proposed 751 kWp rooftop PV system using PVsyst: A case study of Kastamonu University, Türkiye

Rooftop solar photovoltaic (RSPV) systems are increasingly recognized as a vital component of the decentralized energy transition, enabling on-site electricity generation that minimizes transmission losses while advancing institutional sustainability goals. This paper presents a simulation-based techno-economic and environmental feasibility assessment of a proposed 751 kWp grid-connected rooftop PV system at the Faculty of Engineering and Architecture, Kastamonu University, Türkiye, evaluated using PVsyst with three-dimensional near-shading modelling and site-specific meteorological data. The technical performance was assessed through energy yield, performance ratio (PR), normalized losses, and capacity metrics. The annual electricity generation was determined to be 1,126,006 kWh, equating to a specific yield of 1,500 kWh/kWp/year, an average PR of 86.62%, and a capacity factor of 17.12%. The projected annual generation corresponds to approximately 37.4% of the recorded campus annual electricity consumption. The dominant technical loss is thermal, while shading and electrical losses remain minor owing to the optimized tilt configuration. The economic analysis yielded a levelized cost of energy (LCOE) of $0.059/kWh, a net present value (NPV) of $722,239, an internal rate of return (IRR) of 19.91%, and a discounted payback period of 10 years over a 20-year project life. A sensitivity analysis confirmed that the NPV remains positive across all moderate adverse variations in tariff, CAPEX, discount rate, and degradation rate. The environmental life cycle assessment projected a net saving of 8,694 tonnes of CO2 using a Turkish grid emission factor of 0.489 kgCO2/kWh and a year-by-year degradation correction, with an environmental payback period of approximately 3 years. These findings confirm the feasibility of RSPV for institutional energy self-dependency in emerging solar economies.