Energy and exergy analysis of a photovoltaic thermal thermoelectric system integrated with an earth air duct for building applications

Buildings account for a considerable share of global energy consumption, mainly due to heating, cooling, and electricity demands, which highlights the need for efficient renewable energy technologies. Although photovoltaic/thermal–thermoelectric generator (HPVTE) systems and earth–air ducts (EADs) have individually demonstrated promising performance, their integrated application for simultaneous space heating, cooling, and electrification has not yet been comprehensively investigated. To the best of the authors’ knowledge, this study provides the first systematic thermodynamic parametric assessment of the coupled HPVTE–EAD configuration considering both preheating and precooling modes and simultaneous variations in key solar, geometric, and airflow parameters. To address this gap, a thermodynamic model of an HPVTE system coupled with an EAD is developed and analyzed under both preheating and precooling operating modes. In the preheating mode, cold ambient air is preheated as it passes through the EAD and HPVTE subsystems, whereas in the precooling mode, hot ambient air is precooled by the EAD and the HPVTE subsystem is cooled using the air exiting the building. In both modes, photovoltaic panels and thermoelectric generators generate electricity. The effects of solar irradiance, ambient temperature, air mass flow rate, photovoltaic dimensions, EAD geometry, and HPVTE air-channel thickness on the energy and exergy performance are examined. The highest overall energy efficiencies reached 71.66% and 57.90% in the precooling and preheating modes, respectively, while the corresponding maximum exergy efficiencies were 17.25% and 16.60%, all achieved at a solar irradiance of 600 W/m 2 .