Optimal thermochemical material selection for a hybrid thermal energy storage system for low temperature applications using multi criteria optimization technique

Abstract

Thermochemical energy storage is one of the viable solutions for the increasing energy demand because of its high energy density and less heat loss during the storage phase comparing to the other methods. The selection of proper thermochemical material (TCM) is then become important in this type of thermal energy storage. This paper describes the use of Multi Criteria Decision Making (MCDM) techniques to select the optimum thermochemical material from the alternatives to be used for low temperature (<150 °C) energy storage. The best thermochemical material is selected using different MCDM techniques like simple additive method, weighted product model, Technique for Order Preference by Similarity to Ideal Solution, Evaluation based on Distance from Average Solution, Multi-Objective Optimization on The Basis of Ratio Analysis, Preference Ranking Organization Method for Enrichment Evaluation, and VIKOR. The criteria weights for optimization are evaluated by different methods such as mean weight method, standard deviation method, analytic hierarchy process, Entropy method, criteria importance through inter-criteria correlation and Compromised weight method. In all MCDM-Weighting method combinations MgCl2·6H2O ranked first (optimum material) and Na2S·9H2O ranked last. The ranking obtained from various MCDM-weighting method combination are compared with each other using average Spearman rank correlation coefficient and found that Evaluation based on Distance from Average Solution (EDAS), Multi-Objective Optimization on The Basis of Ratio Analysis (MOORA), Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE II) and VIKOR with AHP weighting method have the highest correlation coefficient (rs = 0.9857) and CRITIC-VIKOR method (rs = 0.5143) has the lowest correlation coefficient.