IWRA Proceedings

AbstractDue to the increasing attention to environmental protection issues, the role of small hydropower has gained particular attention. In fact, characteristics and operation standards of small hydroelectric plants give limited environmental impact and are compatible with for multi-purpose systems (such as, drinking water, irrigation, etc) which usually improve the management of water resources. Indeed, the construction of Italian small scale hydro electricity plants registered an important increase in the last years, near 3% in the case of the mini/micro hydropower plants (power < 1 MW) and 2% for those with power between 1 MW and 10 MW. Recent studies concerning the residual potential of small scale hydropower generation in Italy show that there are conditions for increasing the current level of small hydro production. The identification of the potential hydropower at river scale (within a single basin) needs a precise analysis of the water availability in terms of annual stream discharge duration curve coupled with available geodetic falls. The paper presents a GIS integrated numerical tool that allows for the evaluation of the residual potential hydropower energy and all possible alternatives concerning the sites for hydroelectric plants along the drainage network, taking into account the relationship between the full costs of the mini-hydro power and the benefits from selling the generated power in the national market. The tool takes into account the water resources present exploitation with its geographical location and elevations (irrigation uses, drinkable water, existing hydropower plants, etc.), and the limitation that this creates regarding the potential energy patterns. The software is based on the topographic information (Digital Elevation Model) and the isohyets maps, with a whole analysis of the catchment, together with the regional evaluation of available discharges along the river system. Based upon a user friendly graphical interface the tool is able to split the river into a hundreds of cross sections, calculate the available discharges and potential hydropower production, considering constrains like minimum flow, withdrawals and restitutions scheme. Finally, a river case study is illustrated considering the optimization process adopted to define the most appropriate location of a series of small scale hydroelectric plants maximizing energy production and benefit/cost rate. The tool shows to be a quite powerful instrument to support decision makers and stakeholders, for the energy plan preparation, the assessment and the implementation of small scale hydropower plants.