Performance investigation of non-imaging-concentrating photovoltaic thermal systems with metal oxide and ceramic-based nanofluids: numerical study and genetic algorithm-based multi-objective optimization

Abstract

This research originally analyzes the integrated impact of nanofluids and low-concentrating collectors in concentrating photovoltaic thermal (CPVT) systems, employing genetic algorithm optimization to achieve efficiency gains and cost reductions. The study addresses the problem of efficiency loss due to PV overheating and limited exploration of nanofluid-non-imaging concentrator integration. In particular, attention is given to CPVT systems with compound hyperbolic, parabolic, and V-trough concentrators, enhanced by nanofluids. SiC, Al2O3, and ZnO nanoparticles at 1-3 wt% were examined to numerically assess improvements in heat transfer and power output. The results revealed that H2O-SiC with 3 wt% achieved the best electric, thermal, and exergetic performances. SiC 1 wt% outperformed Al2O3 3 wt% by 2.74 % in terms of thermal efficiency. The V-trough system was identified as the best-performing overall energy and efficiency at a normal incidence angle, achieving efficiencies of 70 % (thermal) and 17.37 % (exergy) with 3 wt% SiC. CPC and CHC systems followed with thermal efficiencies of 69 % and exergy efficiencies of 17.27 %. CHC showed superior electrical and comparable thermal efficiency, becoming effective with a sun-tracking system and attractive due to its half-reflector size. The optimal design, CHC-SiC-0.5 wt%, with a 2.86 degrees incidence angle, achieved a cost of $86.9/unit with high thermal (55.31 %) and electrical (12.48 %) efficiencies. Cost was reduced by 60.4 %, with overall efficiency decreasing by only 2.24 %. V-trough systems maximize absolute power output, CPC offers stable performance over wider incidence angles, and CHC achieves the highest power density per reflector area but requires precise alignment or tracking, highlighting the trade-off between total power, angular tolerance, and area efficiency. CHC-based systems, particularly with SiC nanofluids, offer the most economically sustainable solution despite higher efficiency configurations increasing system costs. This work provides the first comprehensive comparative analysis of nanofluid-enhanced CPVT systems with non-imaging concentrators, demonstrating that nanofluid-geometry integration combined with genetic algorithm optimization can significantly improve efficiency while lowering costs. This constitutes the core scientific contribution of the study.