Experimental geothermal monitoring assessing the underground sustainability of GSHP borehole heat exchangers in a protected hydrothermal area: The case study of Ponte Arche (Italian Alps). (September 2018)

• Record Type: Journal Article
• Authors: Viesi, Diego; Galgaro, Antonio; Zanetti, Alberto; Visintainer, Paola; Crema, Luigi
• Is Part Of: Geothermics. Volume 75(2018)
• Page Start: 192
• Page End: 207
• Publication Date: 2018-09
• Subjects: Shallow geothermal sustainability -- Geothermal monitoring -- Ground source heat pump (GSHP) systems -- Borehole heat exchangers (BHEs); Hydrogeology -- Periodicals; Geothermal resources -- Periodicals; Énergie géothermique -- Périodiques; GEOTHERMAL ENGINEERING; GEOTHERMAL ENERGY; GEOTHERMAL EXPLORATION; Geothermal resources; Hydrogeology; Periodicals; Electronic journals; 621.44
• DOI: 10.1016/j.geothermics.2018.05.002
• Languages: English
• ISSNs: 0375-6505

Abstract

Highlights: A geothermal monitoring assessing BHEs underground sustainability is proposed. The real heating and cooling operation ground-side of a GSHP in a NZEB is evaluated. A ground investigation campaign facilitates the monitoring data interpretation. Results of the underground temperature monitoring at different depths are shown. Abstract: An experimental geothermal monitoring, performed on the ground source heat pump (GSHP) system running in a nearly zero energy building (NZEB), has been realized in the protected hydrothermal area of Ponte Arche (Italian Alps), at the request of the competent geological authority. The scope is to assess if a thermal interference could appear between the exploitation of the shallow underground by borehole heat exchangers (BHEs) and nearby thermal baths. Currently, in this area an absolute prohibition for shallow geothermal applications is in force, the area is categorized "potentially subject to geothermal manifestations". However, in light of new geological and hydrogeological knowledge, supported by long-term monitoring, the protection criterion and constraint geometry could be reviewed. Preliminary to the experimental geothermal monitoring, a detailed ground investigation campaign was performed, including: a geological setting overview based on existing cartography, one continuous core drilling, three downhole geophysical surveys, one thermal response test (TRT). The monitored parameters comprehend the underground temperature at different depths, the outdoor air temperature, and the ground-side heat flow of the GSHP. The collected data are presented and discussed, including considerations about the underground sustainability of the BHE field, and about the real heating and cooling operation of the GSHP ground-side.