“…In the literature, various classical and evolutionary based optimization techniques have been developed for solving the optimal ST-HTS problem. Some of the evolutionary algorithms used for solving the ST-HTS problem include: particle swarm optimization (PSO) [4], fully-informed PSO [5], two-swarm based PSO search strategy [6], couple-based PSO [7], hybrid simulated annealing/genetic algorithm [8], quasi-oppositional teaching learning based optimization [9], improved harmony search algorithm [10], successive approximation approach [11], improved TLBO algorithm [12], accelerated PSO [13], flower pollination algorithm [14], symbiotic organisms search algorithm [15], Grey wolf optimizer [16], recurrent neural network [17], modified flower pollination algorithm [18], etc. Some of the literature is also available for solving the multi-objective based ST-HTS problem by optimizing cost and emission using normal boundary intersection and VIKOR in [19], lexicographic optimization and normal boundary intersection method in [20], enhanced multi-objective bee colony optimization algorithm in [21].…”