Performance Optimization of Photovoltaic-Thermal Systems toward Enhanced Dual Energy Production for Building Integration

Abstract

Photovoltaic-thermal (PVT) systems overcome a basic constraint of traditional solar modules by collecting both electricity and usable heat energy from a single integrated collector. In this work, an air-cooled PVT system optimized by coupled thermal-electrical analysis and constrained multi-objective optimization is designed, modeled, and experimentally validated. By prolonging coolant residence time and upsetting thermal boundary layers, the collector's six-baffle flow disruptor shape improves convective heat transfer. The optimized configuration raised electrical efficiency from 12.1% to 15.3% (+26.5%) and stabilized power output at 156.2 W while lowering photovoltaic cell temperature by 8.2°C compared to an uncooled reference under representative operating conditions (623 W/m² solar irradiance, 30°C ambient temperature). At the same time, airflow was used to extract 91.6 W of low-grade thermal energy (0.004167 kg/s), resulting in a system efficiency of 24.6%. A 100 m² array in a Mediterranean climate is expected to generate 12,000 kWh of electricity and 45,000 kWh of thermal energy annually. For residential and light-commercial applications where maintenance simplicity and envelope compatibility are more important than maximum thermal density, the air-cooled architecture offers a practical solution by removing the hydraulic complexity, freeze risk, and scaling management present in liquid-based alternatives. Predictive accuracy within 4% root-mean-square error throughout transient and steady-state regimes was demonstrated by model validation against experimental data. These results show that air-cooled PVT collectors can achieve balanced polygeneration performance with low operational overhead by co-optimizing absorber shape, flow dynamics, and insulation approach.