Multi-objective optimization of a multi-story hotel's energy demand and investing the money saved in energy supply with solar energy production

This study presents a comprehensive proposal for multicriteria optimization of the energy requirement of a multi-story hotel structure, which benefits economically and environmentally. EnergyPlus has been exercised for simulation of a given hotel building and to analysis energy demand. Besides, to implement optimization of building parameters, “Non-dominated Sorting Genetic Algorithm” (NSGA) was applied in JEPlus + EA software. Three building-related parameters have been investigated to optimize energy consumption after sensitivity analysis calculations: building orientation, overhang tilt angle, and overhang depth. Multi-objective optimization has been applied, considering three objectives with equal weight allocated to each factor. These criteria include the energy consumption of heating, cooling, and electrical equipment. The results of multi-objective optimization in the climatic zone of Tehran, show that the total energy demand is reduced by about 118 GJ annually. Furthermore, the long-time saved cost as a result of the optimization is proposed to be invested in the photovoltaic solar system's installation to make the building more sustainable. According to the result derived from Homer Pro software, 2.39 % of the hotel's annual energy consumption will be provided from clean energy. Despite the high cost of renewable energy systems, the costs related to producing electricity reduced significantly.