Design and multi-criteria evaluation of a PV system for a university building aligned with national renewable energy regulations: Penalty-based pricing, roof heat gain reduction, and national-level benefits

This study presents the design and techno‑economic feasibility of a grid‑connected photovoltaic (PV) system for a university’s central building in Iran, in response to a national mandate requiring executive bodies to supply 20% of their electricity consumption from renewable sources by 2027. The system is sized using actual monthly electricity consumption data and local solar resource assessments, resulting in a 302 kWp plant with 432 bifacial panels and three 100 kW inverters. Two installation scenarios—rooftop and ground‑mounted—are evaluated using PVsyst and DesignBuilder simulations. A novel aspect is using penalty rates from Green Board of the Iran Energy Exchange, rather than fixed feed‑in tariffs, for economic assessment. The system generates 520.45 MWh annually, with a performance ratio of 82.2% and a capacity factor of 19.7%. The rooftop scenario reduces roof heat gain by 22.1%, lowering cooling demand by 12.24 tons of refrigeration. Economic analysis reveals a payback period of 5.8 years and an LCOE of 0.0524 USD/kWh. The project also achieves a 95.4% reduction in CO₂ emissions compared to grid electricity. At the national level, it saves 109,338 m³ of natural gas annually, with an export value of €32,801 and an opportunity cost of $42,156 for the exported electricity, demonstrating that rooftop PV systems offer both local and national economic and environmental benefits.