Determination of the Optimal Size of Photovoltaic Systems by Using Multi-Criteria Decision-Making Methods

Abstract

The diverse socio-economic and environmental impacts related to the setup of a new photovoltaic installation must be weighed carefully in order to reach the best possible solution. Among the different photovoltaic systems, there are several classification criteria, depending on the technology, application, and size of the modules that define them. The size (installed nominal capacity) stands out as an impartial and critical measure in the decision-making process. In this article, we use a multi-criteria decision-making method to analyze the responses of five experts to a detailed questionnaire in which several different criteria are correlated with various photovoltaic installation sizes. The limitation associated with a low number of experts is addressed with a robustness and sensitivity analysis. With this study, we seek first to apply and demonstrate the feasibility of a methodology that combines technical information with multi-criteria decision-making methods. Second, we obtain a clear result that increases the benefits of a forthcoming photovoltaic installation of modules in distributed generation, adding up to one GW total peak power in standard conditions. We observe a consistent result in which smaller photovoltaic modules provide the ideal solution, as this format maximizes the socio-economic benefits of any installation. If a decision has to be taken about the type of photovoltaic plant to be installed, the conclusion is clear: given a certain size, small, easily scalable installations are the best solution for stakeholders, the inhabitants, and the environment.