Experimental performance evaluation of phase change material integrated thermoelectric generator

Increasing energy demands have created an urgent need to explore alternative energy solutions. Waste heat, commonly lost in energy production, can be effectively utilised through thermoelectric generators (TEGs). These devices generate electricity when a temperature difference is employed across a thermoelectric material. The efficiency of TEGs can be significantly improved by combining them with Phase Change Materials (PCMs). PCMs help maintain a steady temperature gradient over a longer period, leading to better system efficiency and power output. The goal of this study is to experimentally evaluate the thermal and electrical performance of TEGs integrated with PCMs for efficient waste heat recovery at low temperatures. Two paraffin-based PCMs with distinct thermophysical properties were used to assess their performance during charging and discharging cycles. The results showed that the PCM-1-TEG system achieved an average power output of 0.27 W and an efficiency of 1.11 % during charging, while the PCM-2-TEG system produced 0.28 W and an efficiency of 0.8 %. However, both systems experienced a sharp drop in power and efficiency as the stored energy diminished. During the discharge phase, PCM-1 delivered an average power output and efficiency of 0.03 W and 0.3 %, while PCM-2 achieved 0.029 W and 0.31 %. The selected PCMs enabled continued electricity generation for up to 180 minutes after external heat was removed, highlighting their role in stabilizing the thermal gradient and sustaining power output during discharge. Based on the comparative performance of two PCMs, the results suggest that phase change temperature range and latent heat capacity significantly influence thermal buffering and electrical output behavior. Therefore, these properties should be considered when selecting PCMs for real-world waste heat applications.