Sustainable geothermal energy for two Southern Italy regions: geophysical resource evaluation and public awareness 

Abstract

This work shows the first results of activities carried out in the framework of project TOGETHER - Sustainable geothermal energy for two Southern Italy regions: geophysical resource evaluation and public awareness financed by European Union – Next Generation EU (PRIN-PNRR 2022, CUP D53D23022850001). The deployment and sustainable use of Italy's geothermal resources could represent a key asset to increase renewable energy production and reduce greenhouse gas emissions in the years ahead. Within this context, there is an obvious need for programs to improve subsurface geothermal resource extraction while maintaining environmental sustainability. Assessing the potential exploitation requires knowing the type of geothermal system, the likely temperature and characteristics of the reservoir rocks and fluids. We propose a novel geophysical multi-messenger approach, which provides unique and useful insights into the features and activities of examined geothermal reservoirs. These findings stem from the complementary information carried by subsoil geophysical parameters such as electrical resistivity and elastic/anelastic characteristics related to fluid presence. The proposed method will be tested in two test regions in Southern Italy that are appropriate for low to medium-enthalpy geothermal extraction: Contursi Terme and Tramutola. Contursi Terme is one of the most appreciated thermal sites in the whole Campania region. Here, 77 springs with temperatures ranging from 21°C to 30°C are present; furthermore, 72 shallower and deeper wells for the pumping of hot waters with temperatures ranging from 38°C to 43°C are used for balneotherapy. The Tramutola test site is located on the western side of the Agri Valley (Basilicata region) which hosts the largest onshore hydrocarbon reservoir of Western Europe. During the drilling of the "Tramutola2" well (404.4 m) in 1936, a significant volume of sulphureous hypothermal water (28 °C with a flow rate of 10 l/s) with accompanying gases (mostly CH4 and CO2) was discovered. At the same time, TOGETHER project aims to develop and apply communication methodologies devoted to increasing the acceptance of the exploitation of geothermal energy. This objective will be accomplished by actively engaging local communities and younger generations, who will serve as the foundation for scientific education, social interaction, and constructive debate.