5E assessments and economic–financial viability of an innovative direct-contact photovoltaic thermal system: Experimental and numerical study

Abstract

Photovoltaic-thermal systems (PVT-S) still have several limitations, such as excess weight, expansion constraints on the absorber plate, and insufficient cooling efficiency. To address these issues, this study proposes a new PVT-S configuration incorporating a heat exchanger that allows direct contact between the heat transfer fluid and the rear surface of the photovoltaic (PV) module, and compares its summer performance with that of a reference PV module (PV-M). In order to predict and optimize performance, a three-dimensional model was developed using COMSOL Multiphysics and validated experimentally under the climatic conditions of El Jadida. The results were analyzed in terms of energy and exergy performance and temperature distribution. In addition, the study includes sustainability indicators, an annual and environmental assessment, exergy destruction, entropy generation, and an economic analysis taking into account the payback time (PBT) and the levelized cost of electricity (LCOE). The new PVT-S achieves a maximum thermal efficiency of 76.885% and an average exergy efficiency of 15.313%, with an exergy destruction of 924.712 W and an entropy generation of 3.020 W/ °C. It has an average sustainability index of 1.18084, an average improvement potential (IP) of 783.106 W, an average Waste Exergy Ratio (WER) of 0.84837, and an average ecological exergy indicator (EcEI) of -0.69373. The total annual energy is 2837.86 kWh, reducing CO₂ emissions to 7.922 t/year, compared to 534.81 kWh and 2.920 t/year for the reference PV. The investment cost is 1870.97 $, with a PBT of 4.709 years and an LCOE of 0.11271 $/kWh.

Keywords: Direct heat exchanger, Energy and economic analysis, Exergy analysis, Levelized cost of electricity (LCOE), Photovoltaic-thermal system