Territorial analysis for the energy supply of suburban areas from alternative renewable sources: impacts and potential

This PhD research is part of broader studies promoting renewable energy development in line with the Italian PNRR and EU sustainability goals. Supported by the REACT-EU initiative, the project contributes to advancing knowledge in ecosystem conservation, biodiversity, climate change mitigation, and sustainable development, as encouraged by national and European research strategies. The project involves collaboration with CIDIU S.p.A., a national company supporting the creation of Energy Communities through renewable sources such as solar and hydroelectric power. This initiative focuses on transforming former urban waste management areas into energy production zones, aligning with European guidelines and funding requirements. To support this goal, the study develops a basin-scale assessment of mini-hydroelectric plant feasibility by integrating geological, morphological, hydraulic, and hydrogeological data within a robust methodological framework. For this purpose, was developed ad hoc methodology that incorporates a decision-making process for selecting areas to assess hydroelectric potential. It was created considering as test sites the Stura di Lanzo, Dora Riparia, and Sangone basins, western Turin area (Italy). The study starts by quantifying the temporal evolution of rivers and identifying anthropogenic causes, particularly urban and industrial expansion. Were used historical cartographic data covering the last 150 years, combined with databases on current barriers, allowing analysis of changes in river dynamics and structure in the three water basins. Variations in riverbed morphology were quantified using spatial indices to identify areas most affected by human activity, guiding restoration priorities and policy development. Building on this, the hydroelectric potential assessment incorporated spatial data and annual flow trends from carefully selected stations outside heavily impacted or protected areas. The SWAT hydrological model, calibrated with SWAT-CUP, simulated daily flow rates, enabling the calculation of theoretical hydroelectric potential while considering elevation differences and technical parameters. Environmental constraints from the Water Framework Directive and regional regulations were integrated by applying the Ecological Flow (EF) concept, which preserves the minimum flow necessary to sustain river ecosystems. Hydroelectric potential was recalculated using flow values adjusted to comply with EF and biodiversity protection, providing an environmentally compatible estimate of hydroelectric capacity. Specifically, the three basins show potential for small hydroelectric plants ranging from 100 to 1,000 kW. This obtained potential, together with the spatial distribution of the plants, demonstrates how the application of the EF concept modifies the available flow, thereby influencing the calculated potential. Finally, the impact of small hydroelectric plants on river morphology was evaluated at a subreach scale using the IDRAIM framework and Morphological Quality Index. Two river reaches, Stura di Lanzo and Dora Riparia, were analysed to assess changes in geomorphological functionality and artificiality in relation to hypothetical hydroelectric plan scheme. In conclusion this comprehensive methodology successfully balances hydropower development with ecosystem preservation by integrating historical river morphodynamics, hydrological modelling, regulatory frameworks, and morphological assessments. The findings highlight the critical need for site-specific approaches that respect ecological constraints and regulatory requirements. This framework offers valuable guidance for policymakers, environmental managers, and energy developers aiming to promote sustainable hydropower projects aligned with European sustainability goals and local environmental conditions.