Energy efficiency of thermoelectric photovoltaic systems with thermoelectric cooling: A study based on numerical modeling and parameter identification

The low electrical efficiency of photovoltaic modules, which is further reduced by increasing operating temperature, has motivated the development of hybrid systems capable of recovering heat and improving overall energy performance. This study presents an experimental and numerical analysis of a photovoltaic–thermal system with thermoelectric modules (PVT-TE), consisting of 32 BiSn thermoelectric devices originally designed for cooling but operating here as generators (TEGs). Experimental data obtained under steady-state conditions in a controlled environment were used to calibrate the numerical model, which was later applied to simulate outdoor performance based on real meteorological measurements. The results were compared with those of conventional PV and PVT systems under equivalent operating conditions. In indoor tests, the PVT system achieved the highest thermal efficiency (54 %) and overall efficiency (60.5 %), while the PVT-TE system reached the highest electrical efficiency (6.7 %). Under outdoor conditions, the PVT-TE system reduced the PV module temperature by up to 2.5 °C and increased electrical efficiency by 1.0 % compared to the PVT system; however, this gain came at the cost of an 11.34 % reduction in thermal efficiency. Although the PVT-TE system delivered the highest electrical power per panel (7.51 W), its total useful energy was lower due to the associated thermal loss. • New methodology of numerical models to identify parameters based on real data. • Experimental and numerical comparison with applied to real weather conditions. • Use of multiple TECs as TEGs in PVT-TE hybrid systems. • Use of the semiconductor bismuth-tin (BiSn) in the TECs. • Comparison of electrical and thermal efficiencies of the PV, PVT, and PVT-TE systems.