Multi-objective optimization of an advanced multiscale full spectrum concentrated solar photovoltaic/thermal system with nanofluid beam splitter

This study presents a multi-objective optimization of a multiscale full-spectrum concentrated nanofluid beam splitter-photovoltaic/thermal system (SBS-PV/T system). A fully coupled model integrating solar concentration, spectral splitting, and thermal and electrical components was developed. The sensitivity of nanoparticle type, environmental conditions, system design, and operation parameters was systematically analyzed using analysis of variance. A holistic evaluation was conducted, covering thermal and electrical performance, heat quality, PV conversion, and thermal uniformity, offering an integrated perspective on system optimization. An integrated evaluation was conducted using the entropy weighting method, based on end-user optimization preferences. Results showed that metal nanoparticles outperformed metal oxide nanoparticles, with Au nanoparticles demonstrating the highest effectiveness. Nanoparticle concentration and optical thickness significantly impacted the electrical performance, contributing 42.53 % and 25.48 %, respectively. In contrast, nanofluid velocity and temperature predominantly influenced the thermal energy quality, with respective contributions of 25.07 % and 10.12 %. Through a holistic-objective optimization approach, the proposed system achieved thermal and PV efficiencies of 60.94 % and 30.09 %, respectively. Additionally, the thermal uniformity of the PV panel showed a significant relative increase of 42.18 %, compared to optimization strategies that prioritize only thermal and electrical performance. This study offers insights for the practical design and operation of systems.