Synergistic cooling of photovoltaic panels via MWCNT-coated nanoporous heat pipes and MXene nanofluids: A comprehensive 4E analysis

• MWCNT-coated nanoporous OHPs lower thermal resistance by up to 24.5 %. • MXene nanofluid (0.1 wt %) enhances PV electrical efficiency by 12.2 %. • Hybrid MXene–OHP system increases daily electricity output by 141 W. • Integrated cooling strategy reduces CO₂ emissions, improving sustainability. • Novel MXene–carbon hybrid cooling shows strong potential for large-scale PV. Effective thermal regulation is vital for sustaining photovoltaic (PV) panel performance, as elevated operating temperatures substantially impair energy conversion efficiency. This study introduces a hybrid cooling approach that combines nanoporous oscillating heat pipes (N OHPs) coated with multi-walled carbon nanotubes (MWCNTs) and MXene-based nanofluids. To improve colloidal stability, anhydrous sodium citrate (ASC) was incorporated, and ultrasonication duration was optimized. System performance was comprehensively evaluated using the 4E framework, encompassing energy, exergy, economic, and environmental aspects. Experimental results demonstrate that MWCNT-coated OHPs reduce thermal resistance by up to 24.5 % compared with uncoated counterparts. MXene nanofluids, owing to their high thermal conductivity and stability, achieved a surface temperature reduction and efficiency gain of up to 12.2 % at 0.1 wt% concentration. The integrated N OHP/MXene system enhanced electricity generation by >141 W over a 12-h operating period. Environmental assessment further confirmed significant CO₂ mitigation, reinforcing the sustainability of the proposed design. This study is the first to combine MWCNT-coated nanoporous OHPs with MXene-based nanofluids for PV cooling and the first application of a complete 4E framework to evaluate their performance under realistic operating conditions. While the system entails higher upfront costs, the long-term advantages—including higher energy yield, economic return, and carbon reduction—highlight its potential for scalable, high-efficiency PV deployment.