Application of multi-objective optimization model to assess the energy efficiency measures for the cases of Spain

Maximization of the yearly saved energy (SE) with minimization of the primary investment with regards to the retrofit procedures being decision parameters and assessing the related impacts of them in the utilization of space cooling and heating and expenses, by the selected technology is the major target in this study. To establish the optimum arrangement of retrofitting amounts used to various zones of Spain including Seville, Valladolid, Madrid, and Cordoba, an optimization technique is proposed. To find a solution for the optimization problem a multi-objective Locust swarm optimization algorithm is applied. Variously considered energy effectiveness measures are including the enhancement of the U-values in windows and outer walls by the utilization of insulation materials, the alternation of the lighting characteristics and the model of the refrigerator to decrease the electrical power use, the application of the photovoltaic panels for self-usage, and the Heat Pump utilization to cool and to heat the building space. The cost is affected by various limitations associated with the achievement of the demand, the physical constraint of the building space, the volume to adhere to the cooling/heating requirements, and the non-negativity nature related to the parameters. The optimum retrofitting alternatives are suggested, the budget to employ them, and the measure of obtained SEs. The solutions gave a payback period that goes from 3.64 years for Seville, 2.43 years for Cordoba, 3.31 for Valladolid, and 1.9 years for Madrid on average.