Single-well circulation systems for geothermal energy transfer

• Published in: Environmental earth sciences Vol. 76; no. 7; p. 1
• Main Authors: Zeng, Yifan, Zhou, Wanfang, LaMoreaux, James
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2017; Springer Nature B.V
• Subjects: Biogeosciences; Boreholes; Earth and Environmental Science; Earth Sciences; Energy transfer; Environmental Science and Engineering; Geochemistry; Geology; Geothermal energy; Geothermal power; Groundwater; Heat exchangers; Hydrogeology; Hydrology/Water Resources; Original Article; Terrestrial Pollution; Thermal energy; Water quality; Ground-coupled heat-pump systems; Hydrogeological and thermogeological conditions; Geothermal exchange efficiency; Single-well circulation system
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-017-6621-x

As an alternative method of implementing environmentally friendly geothermal systems for space heating and/or cooling, groundwater has been increasingly used in open-loop ground-coupled heat-pump systems. Of various groundwater heat-pump configurations, the single-well circulation systems tend to provide the best geothermal exchange efficiency where the hydrogeological and thermogeological conditions allow for their installation. In comparison with the closed-loop systems consisting of geothermal boreholes, the single-well circulation systems may substantially reduce the number of boreholes needed, especially for large-scale geothermal applications. In small-scale applications of the single-well circulation system, the groundwater circulation supplies enough thermal energy underground that the temperature of the circulating water remains stable through the years. For district-scale applications, however, further studies are needed to fully understand their sustainability and the impacts on groundwater quality from operating ground-coupled heat-pump systems.