The growing introduction of Renewable Energy Sources (RES) in small and isolated power systems may pose several integration challenges. Typically, this results in the necessity of performing RES curtailment to preserve the stability of the network. This has adverse consequences for the environment, as the replacement is assured by fuel-fired pollutant power stations. To avoid such issues, the RES variability can be compensated with storage systems, in particular Water Pumped Storage Systems (WPSS), which are particularly relevant in island contexts. In this work, we propose a new approach to help the decision-making processes of designing WPPS that are both technical and economically feasible and include the uncertainty of design parameters. This is done by using a metaheuristic optimization method Particle Swarm Optimization that finds out the solution that maximizes the Net Present Value of the project using a model that couples the energy balance model and the economic model. It was found that the input with most impact in the NPV of the projects is the wind energy availability. It is important to mention also the impact of the uncertainty of Capital Expenditure (CAPEX), which, when increases 50% combined with a project reduced lifetime, may lead to a negative NPV. The model, with the necessary adaptations, can be used to study WPSS on similar power systems, therefore contributing to a preliminary assessment of the technical and economic viability of this type of systems.

小型隔离电力系统中越来越多地引入可再生能源（RES），可能会带来一些集成挑战。通常，这导致必须执行RES缩减以保持网络的稳定性。这对环境有不利影响，因为燃料污染的发电厂可以确保更换。为了避免此类问题，可以使用在岛屿环境中特别重要的存储系统（尤其是水泵存储系统（WPSS））来补偿RES的可变性。在这项工作中，我们提出了一种新的方法来帮助设计WPPS的决策过程，该决策过程在技术上和经济上都是可行的，并且包括设计参数的不确定性。这是通过使用一种元启发式优化方法“粒子群优化”（Particle Swarm Optimization）来完成的，该方法使用耦合能量平衡模型和经济模型的模型找出使项目的净现值最大化的解决方案。发现对项目净现值影响最大的投入是风能的可获得性。还必须提及资本支出不确定性（CAPEX）的影响，当资本支出不确定性增加50％且项目寿命缩短时，可能导致负NPV。具有必要修改的模型可以用于研究类似电力系统上的WPSS，因此有助于对该类型系统的技术和经济可行性进行初步评估。