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- Räftegård, Oskar, et al.
(author)
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Energin under mark ska upp till ytan : Strategisk innovationsagenda för geoenergi
- 2016
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Reports (other academic/artistic)abstract
- The Swedish Strategic Innovation Agenda for Geoenergy develops a strategy for highlighting the need for geoenergy research, development and innovation in relation to the business community and authorities. Sweden has a strong global position in the field. Geothermal energy is the thirdlargest renewable energy source in Sweden, along with wind power. Currently, approximately 18 TWh of renewable heat per year is supplied to household, industrial and commercial buildings. In addition, there is 12 TWh of cooling. There is a great need for a longterm strategy and financial plan for geoenergy research and innovation in Sweden, in order to maintain and further develop research groups and the country's leading position in the field. Today, Swedish research in this field comprises about 14 fulltime positions at universities, institutes and companies. This is little compared to the existing use of geothermal energy, about 19 TWh, which is worth about 15 billion SEK in consumer sales. It is also little in relation to possible future contributions to sustainable development in Sweden and abroad. The agenda is divided into short independent chapters that are tailored to different target groups/ applications. Each chapter consists of an introduction to the current situation, how geoenergy can strategically contribute to a sustainable society, and what actions/needs are a priority.
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| 3. |
- Scorpo, Alberto Liuzzo, et al.
(author)
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A method to estimate the hydraulic conductivity of the ground by TRT analysis
- 2017
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In: Ground Water. - : John Wiley & Sons. - 0017-467X .- 1745-6584. ; 55:1, s. 110-118
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Journal article (peer-reviewed)abstract
- An accurate knowledge of aquifers properties is important 2 in many disciplines, from hydrology to site characterization in order to designing and implementing remediation strategies, as well as geothermal ground source technologies. In par5 ticular, the groundwater flow rate is a fundamental parameter to be considered in the ground-coupled heat exchangers (GCHEs) design, together with the thermal properties of the ground. In fact, even relatively low flow rate entail temperature changes considerably lower than in the case of pure heat conduction (Gehlin and Hellström, 2003; Fan et al., 2007) and then relatively stable underground temper10 atures which allow heat pumps to operate with very efficient performance coefficients, thereby reducing energy costs (Lee et al., 2012). Moreover, an accurate knowledge of groundwater velocity and ground thermal properties allows a better design and dimensioning of the GCHE, with further reduction of costs. The objective of this paper is to propose an expeditious, graphical method to estimate the groundwater flow velocity from TRT analysis.
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| 4. |
- Scorpo, Alberto Liuzzo, et al.
(author)
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Influence of regional groundwater flow on ground temperature around heat extraction boreholes
- 2015
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In: Geothermics. - : Elsevier BV. - 0375-6505 .- 1879-3576. ; 56, s. 119-127
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Journal article (peer-reviewed)abstract
- The increasing popularity of ground-coupled heat pumps has resulted in almost20% of all Swedish family houses being heated this way. To avoid undesirableinteractions between neighboring boreholes and disturbance of the ground temperature, the general rule and recommendation of Swedish authorities is that the distance between two neighboring boreholes must be ≥ 20 m. However, according to previous studies, relatively low groundwater flow rates may significantly reduce the borehole excess temperature compared to the case of pure heat conduction. In this work the Influence Length is defined and its relations with flow rate, real thermal conductivity of the ground and effective thermal conductivity obtained by thermal response analysis are investigated. The aim of this study was to find a way to use the thermal response test as a means to determine the groundwater flow influence in order to reduce the borehole spacing perpendicular to groundwater flow direction. The results confirm that very low groundwater flow rates are enough to significantly reduce the Influence Length, hence this is a crucial parameter which should be considered. Moreover, a first estimation, even before the thermal response test analysis, of the Influence Length is possible if the knowledge of hydrogeological conditions of the site allows good predictions about real thermal conductivity of the ground and flow rate.
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