TY - JOUR A1 - Tissen, Carolin A1 - Benz, Susanne A1 - Menberg, Kathrin A1 - Bayer, Peter A1 - Blum, Philipp T1 - Groundwater temperature anomalies in central Europe JF - Environmental Research Letters N2 - As groundwater is competitively used for drinking, irrigation, industrial and geothermal applications, the focus on elevated groundwater temperature (GWT) affecting the sustainable use of this resource increases. Hence, in this study GWT anomalies and their heat sources are identified. The anthropogenic heat intensity (AHI), defined as the difference between GWT at the well location and the median of surrounding rural background GWTs, is evaluated in over 10 000 wells in ten European countries. Wells within the upper three percentiles of the AHI are investigated for each of the three major land cover classes (natural, agricultural and artificial). Extreme GWTs ranging between 25 °C and 47 °C are attributed to natural hot springs. In contrast, AHIs from 3 to 10 K for both natural and agricultural surfaces are due to anthropogenic sources such as landfills, wastewater treatment plants or mining. Two-thirds of all anomalies beneath artificial surfaces have an AHI > 6 K and are related to underground car parks, heated basements and district heating systems. In some wells, the GWT exceeds current threshold values for open geothermal systems. Consequently, a holistic management of groundwater, addressing a multitude of different heat sources, is required to balance the conflict between groundwater quality for drinking and groundwater as an energy source or storage media for geothermal systems. UR - https://doi.org/10.1088/1748-9326/ab4240 KW - anthropogenic heat intensity (AHI) KW - CORINE land cover (CLC) KW - groundwater temperature (GWT) KW - temperature anomaly KW - central Europe Y1 - 2019 UR - https://doi.org/10.1088/1748-9326/ab4240 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-35794 SN - 1748-9326 VL - 14 IS - 10 PB - IOP Publishing CY - Bristol ER - TY - JOUR A1 - Tissen, Carolin A1 - Menberg, Kathrin A1 - Bayer, Peter A1 - Blum, Philipp T1 - Meeting the demand BT - geothermal heat supply rates for an urban quarter in Germany JF - Geothermal Energy - Science, Society and Technology N2 - Thermal energy for space heating and for domestic hot water use represents about a third of the overall energy demand in Germany. An alternative to non-renewable energy-based heat supply is the implementation of closed and open shallow geothermal systems, such as horizontal ground source heat pump systems, vertical ground source heat pump (vGSHP) systems and groundwater heat pump systems. Based on existing regulations and local hydrogeological conditions, the optimal site-specific system for heat supply has to be identified. In the presented technical feasibility study, various analytical solutions are tested for an urban quarter before and after building refurbishment. Geothermal heat supply rates are evaluated by providing information on the optimal system and the specific shortcomings. Our results show that standard vGSHP systems are even applicable in older and non-refurbished residential areas with a high heat demand using a borehole heat exchanger with a length of 100 m or in conjunction with multiple boreholes. After refurbishment, all studied shallow geothermal systems are able to cover the lowered heat demand. The presented analysis also demonstrates that ideally, various technological variants of geothermal systems should be evaluated for finding the optimal solution for existing, refurbished and newly developed residential areas. UR - https://doi.org/10.1186/s40517-019-0125-8 KW - Ground source heat pump (GSHP) KW - Groundwater heat pump (GWHP) KW - Borehole heat exchanger (BHE) KW - Heat demand KW - Refurbishment KW - Geothermal potential KW - GIS Y1 - 2019 UR - https://doi.org/10.1186/s40517-019-0125-8 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-35833 SN - 2195-9706 VL - 7 PB - BioMed Central CY - London ER -