Design, Implementation, and Techno-Economic-Environmental Assessment of a Hybrid Solar Energy System: A Case Study of an Educational Institution in Al-Qubbah, Libya

Abstract

The transition toward renewable energy sources, particularly solar energy, represents a strategic approach to addressing the environmental and economic challenges associated with dependence on conventional energy sources, achieving sustainable development requirements, and reducing carbon emissions. This study aims to design, implement, and evaluate the technical, economic, and environmental performance of a hybrid solar energy system to supply part of the electrical loads of the Electrical Engineering Department at the College of Engineering Technology in Al-Qubbah, Libya.

The study adopted an integrated scientific methodology that included electrical load analysis, hybrid solar system design, and component selection based on operational efficiency and reliability criteria. This was followed by system implementation and operational testing under both no-load and actual operating conditions, in addition to a comprehensive technical and economic performance assessment. Prior to system implementation, the total electrical load of the department was 4500 W, of which 1600 W were supplied by the proposed solar system. Given that the department operates for five hours per day, the daily energy consumption of the supplied loads was estimated at approximately 8000 Wh/day. By applying a safety factor of 20%, the design energy demand was increased to 9600 Wh/day.

The system consists of six photovoltaic panels with a total rated capacity of 2760 W, a 4200 W hybrid inverter operating at 24 V equipped with an integrated 120 A charge controller, four gel batteries with a total capacity of 500 Ah configured to provide a 24 V system voltage, and a comprehensive electrical protection system. The results indicate that the system was able to supply approximately 35.5% of the department’s total electrical load, demonstrating satisfactory operational efficiency and stable performance. Despite the relatively limited annual economic return of about 400 Libyan dinars, attributable to government subsidies on electricity tariffs, the findings confirm the technical and environmental feasibility of the system through reduced conventional energy consumption and lower carbon emissions.