Techno-economic and environmental evaluation of a dynamic solar-biofuel trigeneration system for sustainable building energy applications

The building sector is a major energy consumer and a key contributor to greenhouse gas emissions, making the transition to renewable energy essential for achieving sustainable development. This study investigates a hybrid solar-biofuel trigeneration system designed to supply heating, cooling, and electricity for buildings, aiming to reduce fossil fuel reliance and improve environmental performance. The system integrates photovoltaic thermal (PVT) panels, a biofuel-fired boiler, an absorption chiller, and thermal storage tanks, with its transient performance simulated under real climatic conditions in Beijing, characterized by hot summers and harsh winters. The analysis incorporates techno-economic, environmental, and exergoeconomic assessments, as well as a sensitivity analysis of key parameters, including boiler efficiency, chiller COP, and discount rate. Results show that during winter, biofuel heating ensures reliable supply with peak outputs up to 1980 kW, while in summer, solar energy contributes up to 70 % of cooling demand, reducing biofuel consumption. The system achieves CO₂ emission reductions of up to 0.37 kg/kWh and delivers a levelized energy cost (LEC) between 0.15 and 0.48 $/kWh, depending on seasonal conditions. Novel contributions include the integration of sensitivity and exergoeconomic analyses, as well as an evaluation of the system’s alignment with international green building standards (LEED/BREEAM), providing insights beyond previous studies.