Exergo-economic analysis for screening of metal hydride pairs for thermochemical energy storage for solar baking system

The novelty of this research work is the exergo-economic analysis (including the cost of exergy destruction and exergy loss) of metal hydride based thermal energy storage system coupled with a solar bakery unit for the screening of metal hydride pairs (Case 1: pure MgH₂/LaNi₅ & Case 2: V₂O₅ doped MgH₂/LaNi₅) for thermochemical energy storage. Firstly, a numerical simulation is performed by using COMSOL Multiphysics 5.3a software. Secondly, an economic and exergo-economic model is developed to calculate the annual levelized cost of the thermal energy storage system. The life-cycle economic assessment findings indicate that the Levelized thermal energy storage cost of the pure MgH₂ based system (32.28 $ /kWh_th) is 8.2 times higher than that of the V₂O₅ doped MgH₂ system (3.954 $/kWh_th). Moreover, an 87.75% decrease in cost was observed in Case 2 (V₂O₅ doped MgH₂). Furthermore, Case 2 (V₂O₅ doped MgH₂) can save 92.58 % of hydrogenation reaction time as compared to Case 1 (Pure MgH₂). Ultimately, the selection of V₂O₅ based MgH₂ as a thermal heat-storing medium is then assessed as a better option for the MHTES for the solar bakery unit (SBU). The findings of this research provide a clear insight into the mechanism of cost formation in the system.