The main objective of the REGGAE project is the conception, design, construction and testing of an innovative geothermal system, based on the use of a robust and efficient heat exchanger inserted inside a geothermal well. To achieve this final objective, the partnership worked in sinergy, addressing and overcoming the technical-scientific and administrative difficulties that arose during the project and successfully carrying out research and development activities.

The first project activities were mainly focused on the analysis of the geological and geothermal characteristics of the subsoil, using modern exploration techniques. A geomorphological, hydrogeological and hydrographic study was carried out, as well as geological and environmental monitoring. Furthermore, the most suitable technologies and techniques to build the well were analyzed. In presence of aggressive fluids and high pressures, it is necessary to effectively manage the cementation and welding of the casing.

As regards the heat exchanger, this was designed and developed ad hoc for this project, using innovative numerical modeling techniques capable of analyzing in detail the thermo-fluid dynamic and structural behavior of the exchanger itself and its interaction with the well and the surrounding aquifer. Different geometric configurations were analyzed and modeled, and the optimal configuration of the exchanger was then identified, which allows to maximize the heat exchange, increase the efficiency of the system and avoid the cooling of the surrounding aquifer.

The performance of the innovative geo-exchange system was analyzed both from a numerical and an experimental point of view. Several monitoring campaigns were designed and implemented, in order to experimentally evaluate the effectiveness and efficiency of the innovative geothermal plant. Several performance parameters have been experimentally calculated. The experimental results obtained can be considered very promising. In addition, it was found that continuous operation of the plant for over two weeks did not lead to any phenomenon of groundwater freezing. Finally, on the basis of the results obtained, it is possible to say that the project has been successfully completed.