Passive thermal management of PV solar panels using carbon fiber-enhanced phase change materials: A numerical and optimization study

Abstract

The efficiency of photovoltaic (PV) solar panels decreases with increasing operating temperature, necessitating effective thermal management solutions. Phase change materials (PCM's) have shown promise in passively regulating temperature through their high latent heat capacity. However, the inherently low thermal conductivity of PCM, as highlighted in our previous work, limits its effectiveness and may lead to increased solar cell temperatures compared to systems without PCM. This study addresses this challenge by enhancing PCM thermal conductivity through the incorporation of randomly oriented short carbon fibers. To model the thermal behavior of the composite PCM‑carbon fiber medium, a homogenization technique is employed, reducing computational effort while maintaining accuracy. A three-dimensional transient thermal finite element (FE) model has been developed to examine the spatial thermal behavior of the PV panel, addressing the limitations of earlier one-dimensional models. The numerical homogenization model is coupled with the FE model to perform optimization analysis, identifying the ideal carbon fiber volume fraction that enhances thermal conductivity while preserving the PCM's latent heat storage capacity. The optimized PCM‑carbon fiber system offers a scalable solution for passive thermal management in PV panels, with increased thermal conductivity of the composite medium between 47 % in the solid and 75 % in the liquid state. By reducing peak temperatures, the system enhances energy conversion efficiency and prolongs the operational lifespan of PV cells. The results demonstrate that the passively cooled system reduces the panel's maximum temperature from around 72.5 °C to approximately 57 °C, leading to a daily efficiency improvement of approximately 0.61 % and an enhancement of 4.6 W in daily electric power output. By significantly reducing peak temperatures and improving transient thermal response, the optimized design ensures efficient heat redistribution, addressing thermal hotspots and maintaining panel performance. This study underscores the potential of carbon fiber-enhanced PCM for advanced thermal management in PV applications, offering a computationally efficient and effective solution for energy-efficient solar panels.