Comparative analysis of conventional and triple junction concentrating photovoltaic thermal systems for green hydrogen production in Egypt

Abstract

Abstract Concentrating photovoltaic thermal (CPVT) systems are promising for solar-driven hydrogen production as they enable the cogeneration of electricity and heat when paired with proton exchange membrane (PEM) electrolyzers. Electricity is used to power the electrolyzer, while heat is used to raise the operating temperature of the hydrogen production system and thus reduce the electrical energy required for water splitting. However, the conversion efficiency of conventional solar cells limits wide implementation of this technology. This study presents a comparative techno-economic analysis of a conventional CPVT system against another concentrating system utilizing high efficiency triple-junction cells (C3JT). Parabolic trough solar collectors (PTC) are utilized to attain the desired level of operating power. A comprehensive, dynamic model was developed in MATLAB/SIMULINK/SIMSCAPE environment, integrating validated sub-models for the solar concentrator, PVT receivers, and a PEM electrolyzer. The model was validated against experimental data available from the literature with acceptable validation accuracy. The systems were simulated based on one year of hourly meteorological data for multiple sites in Egypt. The results demonstrate a significant performance advantage for the C3JT system which produced 56.45% more hydrogen annually averaged among the multiple locations and achieved an averaged reduction of 22.22% in the levelized cost of hydrogen (LCOH) compared to the conventional CPVT system. The overall system efficiency (on an HHV basis) increased from 4.99% for the CPVT system to 7.84% for the C3JT system, confirming a more effective conversion of solar energy into chemical energy. The study also concludes that triple-junction photovoltaics are a critical technological upgrade for enhancing the efficiency and economic viability of solar-hydrogen systems despite their higher initial cost.