Solar PV integration in commercial buildings for self-consumption based on life-cycle economic/environmental multi-objective optimization

In this study, a new multi-objective optimization approach is introduced to optimize economically and environmentally the implementation of solar photovoltaic systems for self-consumption under the scenario of zero export injection. Such a scenario is encountered in several developing countries, but up to the author's knowledge, no previous study dealt with its detailed assessment and optimization. The problem formulation considers using the levelized cost of electricity (LCOE) and the cumulative environmental benefit (CEB) as two life-cycle conflicting objective functions. First, a multiple linear regression technique was developed to predict accurately the PV power generation under a time resolution of 15 min as recommended for PV-self consumption studies. A new mathematical expression was as well derived to calculate more accurately the CEB considering both the degradation of the PV productivity over the project lifetime and the dynamic evolution of the electricity mix of the country with respect to time. A Genetic algorithm (GA) is used to identify Pareto frontiers and Technique for Order Preference by Similarity to Ideal Solution "TOPSIS" decision-making method is employed to select the final optimum. The followed approach was applied for a large Moroccan commercial structure with an annual electric load of 2.932 GWh. It was found that the recommended optimum PV installed capacity is 847.4 kW(p). This optimized design leads to the best compromise between economic and environmental aspects and the LCOE is 15.12 c$/kWh while the CEB is 7.89 tonnes CO2. The corresponding self-sufficiency and self-consumption ratios were estimated at 41.41% and 79.14%, respectively. (C) 2020 Elsevier Ltd. All rights reserved.