Synthesis and characterization of high thermal conductive leak resistant phase change material for solar photovoltaic panel cooling applications

Efficient cooling of solar PV panels is vital for optimizing their performance. Phase-change materials (PCM) present a viable option for panel cooling due to their ability to reduce temperature. However, 1-tetradecanol (base PCM) faces challenges such as low thermal conductivity, potential leakage tendency during phase change, and volume expansion. While high thermal conductive leak-resistant composite PCM address these issues, they are often costly due to conventional supporting materials. The nano-enhanced activated biochar-based PCM samples developed in this study offer an economical and sustainable solution for passive solar PV cooling applications. Various characterization techniques, including FTIR, XRD, SEM, BET, DSC, and TGA, were utilized to analyze pure PCM (1-tetradecanol) combined with activated biochar at loadings ranging from 10 % to 40 % by weight. From the leakage results reveal that PCM containing a minimum of 40 % activated biochar (sample-7) demonstrates high resistance of leakage. Furthermore, the study also examined thermal conductivities, enhancement of thermal conductivity, thermal effusivity, thermal effusivity enhancement of 1-tetradecanol (base PCM) and composite PCM. The thermal conductivity and thermal effusivity enhancement of activated biochar-based PCM is investigated through the incorporation of graphene material at concentrations of 0.5 % and 1 %. Results from FTIR and XRD analyses confirm that the interaction between activated biochar, graphene particles, and 1-tetradecanol PCM is physically and chemically stable. The thermo physical properties of the composite PCM samples, including phase transition temperature and latent heat value, are evaluated using Differential Scanning Calorimetry (DSC). The addition of activated biochar and graphene particles leads to a decrease in the latent heat value of the PCM, while the thermal conductivity experiences a significant increase of up to 526.42 %. These findings show that the incorporation of activated biochar and graphene nanoparticles not only maintains the stability of 1-tetradecanol PCM but also mitigates any potential leakage. Moreover, the corrosion rates of copper, aluminum (Al), brass, and stainless steel are determined by immersing them in both 1-tetradecanol PCM and composite PCM for duration of 24 weeks. Metal samples are immersed in the composite PCM demonstrate significant resistance to corrosion.