The integration of photovoltaic (PV) systems in buildings is crucial for reducing reliance on conventional energy sources while promoting sustainability. This study evaluates and compares three energy generation systems: rooftop PV, building-integrated photovoltaics (BIPV), and a hybrid combination of both. The analysis covers energy production, economic feasibility through the levelized cost of electricity (LCOE), and environmental impact by assessing unreleased carbon dioxide (UCD). A residential building in Kerman, Iran, serves as the case study. The results indicate that rooftop PV exhibits the lowest LCOE at USD 0.023/kWh, while BIPV has a higher LCOE of USD 0.077/kWh due to installation complexities. The hybrid system, combining both technologies, achieves a balance with an LCOE of USD 0.05/kWh while maximizing energy generation at 16.2 MWh annually. Additionally, the hybrid system reduces CO₂ emissions by 9.7 tons per year, surpassing the standalone rooftop PV (5.0 tons) and BIPV (4.7 tons). The findings highlight the synergistic benefits of integrating both PV systems, ensuring higher self-sufficiency and enhanced environmental impact. This research underscores the necessity of comprehensive urban energy planning to optimize renewable energy utilization and accelerate the transition toward zero-energy buildings.

The growing demand for energy has led to the popularity of building integrated photovoltaic (BIPV) systems. However, photovoltaic (PV) system efficiency decreases as the temperature increases. To address this issue, a study was conducted on a BIPV thermal (BIPVT) system, which can generate both thermal and electrical energy, to enhance its efficiency. In this study, for the cold weather in Tabriz city in Iran, BIPV and BIPVT systems are compared with each other in terms of energy, economy, exergy, and environment (4E) and the goal is to fully supply the thermal and electrical load of the desired building. The studied criteria are electrical power and heat recovery, payback time (PBT), exergy efficiency, and saved carbon dioxide (SCD) from the energy, economic, exergy, and environmental point of view, respectively. Finally, it is concluded that in cold weather, the BIPVT system can achieve a 7.15% improvement in produced power compared to the BIPV system and 52.2% of the building’s heating needs are provided. It also causes the exergy efficiency to improve by an average of 1.69% and saves 34.98 ton of carbon dioxide. The PBT of this study is calculated as 5.77 years for the BIPV system and 4.78 years for the BIPVT system.