• Energy Research

This paper presents a multidisciplinary methodology to estimate the underground heat-exchange potential for Borehole Heat Exchangers (BHEs) coupled with Ground Source Heat Pumps (GSHPs) over wide areas. The proposed methodology was tested in four sites in western Sicily (southern Italy) where the shortage of subsurface geological data, in addition to the undefined authorization processes for this kind of system, is probably the main barrier to planning and exploiting geothermal heat for heating and cooling purposes. Reliable high-resolution 3D geological and petrophysical models were built based on the integration of airborne electromagnetic data and laboratory measurements of the thermal properties of rock samples. A GIS-based procedure was applied to assess the geothermal heat-exchange potential using 3D models of thermal conductivity as the main input. The results of the analyses are represented by thematic maps of the underground heat exchange potential for BHEs coupled with GSHPs. The study areas show a generally high suitability for the use of this technology and several municipalities in the area could take advantage of the resulting maps for energy planning.

A novel procedure for estimating the geothermal energy exchanged by a unit volume was tested in northern Sicily (Italy), where public well data for depicting the complex geological setting were insufficient. An airborne electromagnetic survey was carried out in 2011, providing a 3D cell distribution of resistivity values. The integrated analysis of geological and resistivity data was used to identify six Litho-Electrical Units and to build a 3D geological model. This model was integrated with laboratory thermal conductivity measurements on rock samples, and was used to characterize the heat exchange at depths of up to 200 m, which in turn can be exploited for planning and designing geothermal heating and cooling plants using GSHP (Ground Source Heat Pump).

Geothermal plants have been producing power in Italy for more than a century. Since local opposition to geothermal development is often fuelled by incomplete and inaccurate environmental information, this paper provides a comprehensive description of the effect of geothermal development on the air, water and soil and investigates potential disturbance from noise, subsidence, and seismicity, as well as the visual impact on the local area. After discussing the risks associated with the geothermal development and the reference data, the paper describes the wide-reaching environmental monitoring and mitigation measures in Italy that have maintained impact values below the thresholds defined by European and Italian regulation. The social benefits for areas where geothermal energy is developed are also described, with the aid of case studies highlighting that citizens do not feel that they are sufficiently informed to have a voice in the innovation process. A regular and comprehensive review of the geothermal environmental and safety regime, as the one carried out in this paper, and a mutual exchange of knowledge between the different stakeholders should be strongly encouraged.

We exploit the concept of the geothermal favourability, widely used for hydrothermal and EGS systems, to present an innovative methodology for assessing geopressured-geothermal resources occurring in terrigenous units in sedimentary basin plays. Geopressured-geothermal systems are an unconventional resource for power trigeneration exploiting three forms of energy from hydrocarbons, hydrothermal fluids, and well-head overpressure. This paper is intended to be a practical analytical framework for the systematic integration of the relevant data required to assess geopressured-geothermal resources. For this purpose, innovative parameters were also implemented in the methodology. The final result is the favourability map for identifying prospective areas to be further investigated for the appraisal of the geopressured-geothermal potential. We applied our methodology to the foredeep-foreland domains of the Apennines thrust belt in the Abruzzo region (central Italy). We analysed hundreds of deep hydrocarbon wells in order to create 3D geological and thermo-fluid dynamic models at a regional scale as well as to obtain information on the pressure regimes and on the chemistry of the system. The final favourability map for the Abruzzo case study is a first attempt at ranking these kinds of unconventional geothermal resources in a region that has been historically explored and exploited mostly for hydrocarbons.

This paper describes a data integration tool used to identify potentially undiscovered geothermal resources in the island of Sicily. The factors facilitating the recovery of exploitable geothermal energy were defined, and their spatial correlation established by Geographic Information System (GIS) models.By prioritizing favourable conditions using an Index Overly method, "favourability" maps of Sicily were obtained. The maps considered both geological and economic aspects, and energy recovery was considered for current technologies. Our approach and maps are useful for developing and planning local or national energy policies including geothermal energy.

In the frame of the Integrated Method for Advanced Geothermal Exploration (IMAGE) Project, a reliable exploration and resource assessment workflow was implemented on the basis of an integrated and multidisciplinary approach. Our study addressed to a better understanding of the thermal structure of the deepest part of the Larderello geothermal field (Southern Tuscany, Italy) by integrating structural, geological, geochemical, geochronological, petrological and geophysical data. With the aim to characterize the reservoir located nearby an important seismic reflector (the K-horizon), we systematized the available data and, successively, we applied a numerical thermal modelling approach to test our hypotheses and concepts.