Although Italy boasts an age-old and solid experience in the exploitation of geothermal energy for power generation, very limited was the development regarding the direct uses. However, recently the interest in low enthalpy geothermal energy is growing mainly because, unlike the other kinds of green energies, the geothermal energy suitable for direct uses can be found anytime and almost everywhere. Particular attention should be paid to the open-loop geothermal systems that use groundwater as geothermal fluid. The installation of these kind of geothermal systems is particularly attractive in the coastal areas where, generally, the aquifers are shallow, and often affected by seawater intrusion. In this work an experimental approach was proposed for a detailed characterization of a costal area finalized to exploitation of low enthalpy geothermal resource. A costal karst area near Bari (Southern Italy), extended for about 20 Km2, was investigated. A specifically defined monitoring network, consisting of about 35 wells, was used to monitor groundwater parameters (temperature, water level, electrical conductivity). The influence of an open-loop geothermal systems on the sea water intrusion was also studied by means of a long-term pumping test. The investigated portion of aquifer was found to have a high hydraulic conductivity and transmissivity values, as well as a very short time of recharge, highlighting a good productivity of aquifer. The results of the long pumping test have showed that, the extraction of water does not affect the equilibrium of the aquifer both qualitatively and quantitatively. The high level of contamination observed in groundwater, due to both the presence of urban and industrial pollution and to the seawater intrusion, causes the absence of a strong competition for use of groundwater by making them available for geothermal use. Overall the experimental approach utilized for this study represents a good effort to define a standard methodology in order to characterize a coastal area. This approach reveals useful for a feasibility study to install an open-loop geothermal system, and to support the potential geothermal evaluation.
Exploitation of low enthalpy geothermal resource: the case study of a coastal area affected by seawater intrusion
Masciale R;Caputo M C;De Carlo L
2013
Abstract
Although Italy boasts an age-old and solid experience in the exploitation of geothermal energy for power generation, very limited was the development regarding the direct uses. However, recently the interest in low enthalpy geothermal energy is growing mainly because, unlike the other kinds of green energies, the geothermal energy suitable for direct uses can be found anytime and almost everywhere. Particular attention should be paid to the open-loop geothermal systems that use groundwater as geothermal fluid. The installation of these kind of geothermal systems is particularly attractive in the coastal areas where, generally, the aquifers are shallow, and often affected by seawater intrusion. In this work an experimental approach was proposed for a detailed characterization of a costal area finalized to exploitation of low enthalpy geothermal resource. A costal karst area near Bari (Southern Italy), extended for about 20 Km2, was investigated. A specifically defined monitoring network, consisting of about 35 wells, was used to monitor groundwater parameters (temperature, water level, electrical conductivity). The influence of an open-loop geothermal systems on the sea water intrusion was also studied by means of a long-term pumping test. The investigated portion of aquifer was found to have a high hydraulic conductivity and transmissivity values, as well as a very short time of recharge, highlighting a good productivity of aquifer. The results of the long pumping test have showed that, the extraction of water does not affect the equilibrium of the aquifer both qualitatively and quantitatively. The high level of contamination observed in groundwater, due to both the presence of urban and industrial pollution and to the seawater intrusion, causes the absence of a strong competition for use of groundwater by making them available for geothermal use. Overall the experimental approach utilized for this study represents a good effort to define a standard methodology in order to characterize a coastal area. This approach reveals useful for a feasibility study to install an open-loop geothermal system, and to support the potential geothermal evaluation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
