In this work, the assessment of power harvesting in electronic modules during its operation is experimentally investigated. The phase change material (PCM) based natural cooling is analyzed with a developed model using different circulating fluids such as DI water, ethanol, and methyl acetate respectively. The experiments are conducted to evaluate the power harvesting by PCM for circulating fluids at the different heat input between 60 and 110 W. Result implies that (i) highest percentage of waste heat extraction is about 98.7% for methyl acetate because of low boiling point and heat of evaporation at high heat input (ii) thermal resistance of methyl acetate is less of about 0.237 K/W owing to high vapour flow rate and less subcooling effect (iii) the maximum power harvested by PCM with the effect of vapourized methyl acetate is found as 9.41 W owing to less time to reach the steady-state temperature (SST) of PCM at 110 W.