Simulation-Based Design of Small-Scale Hydropower Plants for Renewable Energy Communities in Italy

The growing establishment of Renewable Energy Communities (RECs) in Italy, driven by the European RED II Directive, has created a need for simulation tools to support their technical design. While photovoltaic systems dominate REC installations due to their modularity, small-scale hydropower remains an underutilized yet promising option, particularly in water-rich regions. Meanwhile, the increasing adoption of electric vehicles and the expansion of charging infrastructures are expected to further elevate the strategic importance of RECs, as they offer a decentralized framework capable of managing local energy generation and consumption more flexibly. This paper presents the development of a simulation tool for the preliminary design and optimization of small-scale hydropower plants tailored to REC configurations. The tool integrates with the existing Renewable Optimization Simulation Environment (ROSE) platform and allows users to assess multiple turbine technologies based on site-specific flow data, net head inputs, and regulatory incentive thresholds. It employs a flow duration curve-based optimization algorithm to determine the optimal turbine type and configuration that maximizes annual energy production while respecting ecological constraints. The model is validated against real-world data from a run-of-river hydropower plant in northern Italy, showing a production deviation of less than 11% under calibrated conditions. Results demonstrate the tool's effectiveness in supporting the early-stage design of REC-integrated hydropower installations and highlight areas for further improvement, including dynamic efficiency modeling and expanded geographic coverage.