Enhancing PV/T system efficiency with MAX phase/water nanofluids: Experimental insights into optimal cooling strategies

To boost the rear-end cooling of hybrid solar photovoltaic/thermal (PV/T) systems, this research employs a two-phase closed thermosyphon (TPCT) setup with a MAX phase/water nanofluid and presents a performance and efficiency comparison across different PV/T systems. While MAX phases have been largely overlooked in solar applications, they provide approximately 15 % higher thermal conductivity and 30 % lower cost than MXenes, which dominate current PV/T research. Experimental analysis is conducted to assess the influence of inclination angle, filling ratio, and nanofluid concentration on the system's thermal and electrical performance. The optimal tilt angle is identified as 30°, which maximizes solar energy absorption. Additionally, a filling ratio of 50 % yielded the highest energy output and significant temperature reduction behind the panels, demonstrating superior performance compared to conventional PV systems. The impact of nanofluid concentration is evaluated at 0.5, 1, and 1.5 wt%. The study found that using a 1 wt% nanofluid instead of the base fluid significantly lowered the temperature behind the panel, boosted electrical output, and improved overall efficiency. With 1 wt% MAX phase, the temperature decreased by 19.9 °C, while the electrical output increased by 1.68 W. Additionally, using this MAX phase/water nanofluid in thermosyphon cooling, the PV/T system showed a 19.63 % improvement in electrical efficiency over the traditional PV system. These findings highlight the unique role of MAX phases, offering a more cost-effective and thermally efficient alternative to MXene-based fluids. This pioneering approach opens new avenues for enhancing PV/T system performance through advanced nanomaterial engineering.