A GIS-based methodology for hydropower potential assessment: balancing energy production and ecosystem sustainability

Italy leads Europe in hydropower production, with small-scale hydropower plants dominating due to their alignment with local geography and water resources. Despite this leadership, future growth is expected to stagnate, highlighting the importance of assessing the spatial distribution of existing plants in relation to hydropower potential. This study presents a GIS-based methodology integrated with the SWAT hydraulic model in the Stura di Lanzo basin as test site to identify and evaluate potential hydropower sites in territorial diverse context. The workflow of methodology includes selecting points of interest based on proximity to energy demand and existing infrastructure, filtering locations through environmental regulations, calculating flow availability using simulated daily discharge data, and estimating hydropower potential by analysing head values and segmenting rivers. Furthermore, to achieve Goal 6 of the United Nations Sustainable Development Goals, the release of Ecological Flow (EF) was evaluated. In Italy, this release is regulated by the Regionals Regulation, which in Piemonte, so far, only ensures the release of EF at certain test sites. In the context of this study, the hydropower potential is computed considering both a theoretical power and an environmentally compliant power, with the application of EF concept. Results from a 20-year analysis (2002–2022) identified a significant difference in the daily hydropower production due to the application of EF. In this last case 85 potential sites were selected, considering 50% flow exceedance rate, with 40% of sites with average annual rated power of 100–250 kW. At a 75% exceedance rate, 67 sites were identified, with similar rated power outputs but increased seasonal variability. The findings emphasize the importance of EF analysis in preserving biodiversity while enabling sustainable hydropower development. This approach offers a cost-effective planning tool adaptable to regions with existing or planned hydropower infrastructure, supporting strategic decisions for balanced ecological and energy goals.