According to the aim of achieving the highest level of environmental sustainability, an open-loop geothermal system has been planned for thermal needs (warming and cooling) of a large public building that will host a bibliotheque, a theatre and many civil buildings for universitary studies.
The system is located into the shallow (phreatic) aquifer hosted into alluvial Pleistocenic deposits drained by the river Po; initially designed for a supply < 100 l/s, it will be up-graded in order to cover the whole needs of the thermal station of the complex of buildings called “To-Expo”, with a nominal discharge of 160 l/s.
The test-site is located into a wider analysis area, in which existings data sets concerning stratigraphic and hydrogeological pattern have been collected and updated also by groundwater levels measurements, toward the end of an extraordinary recession period (2022), fixing the minimum reference conditions of flow into the aquifer.
The project has been supported by an exaustive ground survey that has been set up into the test-site area, by geophysical investigations (ERT, MASW, HSVR profiles), direct sampling (boreholes, piezometers) and hydraulic and laboratory testing.
The simulation numerical model (finite element model – FeFlow with supermesh grid) has been implemented to reproduce the present-state but above all flow and heat transport scenarios, considering 4 extraction and 4 inflowing wells and a piezometric control network too. The model covers a wider area discretized with 6 computations layers, settled around and inside the open-loop system, determining external and internal boundary conditions and sink/source terms, both flow and thermal, in transient conditions, estimating the evolution of the thermal plume in exercise mode referred to a 20-years scenario.
The whole plant has been approved by the Local Authorities, and the wells drilling program is currently ongoing.