Pyomo-based modeling and experimental validation of a bifluid Photovoltaic-Thermal (PVT) collector

This paper presents a comprehensive, equation-oriented dynamic model of a bifluid Photovoltaic-Thermal (PVT) collector, developed and solved within the Python-based Pyomo framework. The primary novelty of this work is the establishment of a validated, realistic modeling tool that accurately captures the complex, competitive thermal dynamics inherent to dual-fluid systems. The collector, designed for enhanced cogeneration, features distinct air and water circuits to maximize thermal extraction and mitigate PV efficiency degradation. The model, formulated as a system of coupled partial differential–algebraic equations, is rigorously validated against experimental data from a full-scale prototype across different seasons. Excellent agreement is achieved, with summer Root Mean Square Errors (RMSE) of 0.93 K for PV cell temperature and 0.75 K for both air and water outlet temperatures, and comparable accuracy in winter conditions. A subsequent in-depth parametric study quantifies critical performance trade-offs. Results reveal a direct competition for thermal energy: increasing the air mass flow from 0.0074 to 0.06 kg/s nearly quadruples its thermal output but reduces the water circuit’s capture by over 33%, highlighting the necessity of intelligent operational control. The study culminates in system-level techno-economic analyses for European and North African climates, demonstrating the collector’s viability and providing key financial metrics like Levelized Cost of Energy (LCOE). This work establishes a validated model and underscores the power of equation-oriented platforms for analyzing and optimizing complex, multi-physics energy systems.