Effect of adding alumina nanoparticle in D-Mannitol for reversible solar thermoelectric power generation: An experimental study

Abstract

Solar thermoelectric power generation during the day and night-time are achieved using Alumina Nano-Enhanced Phase Change Material on the Thermoelectric Generator (TEG) cold side. The portion of the thermal energy is used to produce electricity using TEG while the rejected heat is stored in a D-Mannitol as Phase Change Material (PCM) during active hours as thermal energy. Thus, continuous power generation is achieved using Nano-Enhanced D-Mannitol (NEDM) as the PCM. The performance parameters of TEG including voltage, current and power profile of the NEDM were recorded. The experimental setup was established for thermosyphon passive and natural convection cooling. For different mixtures, heat inputs and for both types of cooling the electrical parameters were analysed for open power output and circuit voltage. A 99% D-Mannitol + 1% Alumina nanoparticle composition was observed as the optimal composition for all heat inputs and cooling. Subjecting the optimised composition to heat inputs of 10 W, 30 W, 60 W and 90 W along with thermosyphon cooling led to increased maximum average TEG electrical power outputs of 0.23 W, 1.09 W, 1.27 W and 1.33 W respectively, each being 4.04, 4.99, 3.05 and 3.24 times higher than the corresponding values of the natural cooling phase.