How to cite: Ryder, S., Rohse, M., and Abesser, C.: Risk perception, regulation, community engagement and acceptance: Navigating the legal and social UK geothermal landscape , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2328, https://doi.org/10.5194/egusphere-egu22-2328, 2022.

Minewater heating is a form of shallow geothermal energy provision that exploits abandoned subsurface mines that have since flooded after mining activity ceased. Groundwater that occupies the void space left from material extraction is warmed to ambient temperatures by heat transfer exchanges with the surrounding rock.

By using ground source heat pumps, the temperatures of these waters can be lifted to those suitable for domestic heat use, with efficient electrical input.  

An assessment to determine the feasibility of the implementation of a minewater heating system on the Durham University campus is currently in progress, with results due in March 2022. The system would use abandoned coal mines of the Durham Coalfield to heat several student accommodation buildings built above.

Assuming abstraction and reinjection of the minewater, we investigated the available heat resource using a numerical modelling tool developed at Durham University. This tool modelled the minewater flow through the void space of the mines and thermal interaction with the surrounding rock.

A new methodology was developed for the digitisation of historic mine plans provided by the UK’s Coal Authority, which have then been modelled to provide 3D visualisation of technical factors critical to the success of such a project. Various configurations have been tested, and results indicate over 11 million kWh of heat in place resource available, at temperatures of 14°C. This heat in place figure is likely an underestimation of the resource as records indicate deeper seams were also mined at the locality.

We subsequently carried out an assessment of the economic feasibility. If a decentralised configuration were chosen for the design, it would be advisable to focus on three buildings with the most student rooms. Initial costs would be high, driven mainly by the associated costs of drilling injection and extraction wells. As the target seams are relatively shallow (145m for extraction and 70m for injection), smaller wells could be used, costing roughly £40,000 per well. If a centralised design were used, costs would be reduced by drilling fewer wells. However, retrofit work to replace the original centralised gas infrastructure connections could induce significant cost and disruption. However, running costs would be low, and emissions savings from not using gas boilers would be significant; peak daily CO₂ emissions from gas were 17,992 kg in 2019.

Finally, to assess the internal policy structure of the university and the feasibility of permission to be granted for the project, a social acceptance study was undertaken with key members of the university’s Board of Directors. Considering the project through the concept of risk, obstacles to implementation were identified, and potential policy solutions were developed.

This study provided insights into current institutional views on engaging with innovative energy technologies. Future work may benefit from understanding these to produce relevant solutions to mitigate them in their feasibility studies.

How to cite: MacKenzie, M., van Hunen, J., and Gluyas, J.: A feasibility assessment of the implementation of a minewater heating system on the Durham University estate., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4288, https://doi.org/10.5194/egusphere-egu22-4288, 2022.

The geothermal energy potential in the Balkan area includes locations in Slovenia, Hungary, Romania, Bulgaria, Serbia and Bosnia and Herzegovina. Although the potential for clean, cost-efficient, and renewable geothermal heating energy is well known, exploitation of geothermal sources is still hampering. According to the existing surveys, mappings, and calculations, Banja Luka area is built on a geothermal underground reservoir, which is currently only used for balneology purposes. Due to the specific geographic position and the emissions from the existing district heating system based on biomass and heavy petrol, the air quality in Banja Luka is severely mitigated during the winter season. In order to assess the potential and the challenges of geothermal district heating for Banja Luka numerical energy modeling, life cycle analysis of the energy systems, and stakeholder assessment are currently being performed. These activities are currently carried out in the frame of international cooperation between the University of Banja Luka, Reykjavik University in Iceland, and the Energy Institute at the Johannes Kepler University in Linz, Austria. Our preliminary results indicate that geothermal district heating in Banja Luka can provide a reliable, cost-efficient, clean, renewable, and domestic heat supply to the residents of Banja Luka. Furthermore, our initial findings indicate that that the main challenges in developing geothermal district heating in Banja Luka are complex bureaucratic processes, high skepticism among the decision-makers, and a high degree of conflicting interests among relevant stakeholders. This presentation will conclude by highlighting how geothermal district heating in Banja Luka falls in line with the concepts of the new EU Green Deal and the obligations of Bosnia and Herzegovina according to Energy Community Treaty.

How to cite: Gvero, P., Jón Ásbjörnsson, E., Finger, D., Kotur, M., Musonye, X., Kardas, D., and Pupcevic, M.: The potential of geothermal district heating in the city of Banja Luka, Bosnia and Herzegovina, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6292, https://doi.org/10.5194/egusphere-egu22-6292, 2022.

Geothermal high enthalpy resources can be an important potential source to satisfy Mexico’s energy requirements ; nevertheless, low and moderate enthalpy resources may contribute through the direct uses to replace fossil fuels. In both cases, the exploitation of geothermal resources are an important factor inthe energy transition that the whole world strives to achieve. Furthermore, it has an important social impact in the communities, where the use of geothermal energy can bring considerable benefit. In this work, a geothermal characterization with a geographic approach is presented for the “Atotonilco” (hot water in native language) town in Calcahualco municipality of Veracruz state (eastern México). The surface manifestations in the area are calcium-carbonate warm springs with flows from 1 to 12 liters per second. The temperature at depth was estimated between 70°C and 74°C with the calcedony geothermometer, which corresponds to a low enthalpy resource. A preliminary conceptual model of the Atotonilco geothermal area, using all data and a list of the feasible direct uses applications are proposed. These proposals consider the social and economic characteristics of the study area that were observed during the field work. The recommended actions include dissemination of the results of this research, as an important contribution to the development of geothermal resources in Atotonilco town.

Keywords: Geothermal energy, environmental geography, renewable energy, direct use, geochemical exploration, geoscience dissemination.

Acknowledgment

Thanks to Dr. Ramón Espinasa Pereña for his technical support during the field work. Thanks to the Laboratory of Analytical Chemistry of the Institute of Geophysics, UNAM, especially to the QFB Olivia Cruz, M in Ing. Alejandra Aguayo and QFB Omar Neri, for carrying out the chemical analyzes of water presented here.

How to cite: Baizabal Gómez, E. D., Jácome Paz, M. P., Pérez Zarate, D., de la Fuente Rivera, J. R., and Prol Ledesma, R. M.: Characterization of Atotonilco geothermal area, Veracruz, Mexico, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10599, https://doi.org/10.5194/egusphere-egu22-10599, 2022.

Increasing the share of renewables in the heating sector is crucial to reduce CO₂-emissions. Using the shallow geological subsurface for heating and cooling is part of the solution. Especially the use of shallow geothermal energy for heating is widely applicable. An intensive but at the same time sustainable shallow geothermal use is essential to avoid interactions between geothermal users with a resulting decrease in system efficiency or competing use with other subsurface usages, e.g. groundwater provision. The intensive thermal use of the shallow subsurface is generally controlled by monitoring of subsurface or groundwater temperatures. Induced changes of subsurface or groundwater temperatures are required to not exceed specific thresholds over time. However, the urban subsurface is exposed to different sources of temperature impacts which need to be considered during the long term subsurface or groundwater temperature monitoring to determine absolute changes. This is especially true for new urban quarters. Elevated groundwater temperatures in densely populated areas in comparison to the rural surroundings, often referred to as groundwater urban heat islands, have been observed and investigated over decades. However, only little information is available about the formation of heat islands over time and yet, its effects are hardly considered in groundwater temperature monitoring practice. To overcome this lack of knowledge, this study follows an innovative approach by coupling simulated elevated groundwater temperatures for a densely settled quarter with empiric groundwater temperature data. Therefore, heat losses from buildings and their contribution to the formation of groundwater urban heat islands over time are analysed for a refurbished quarter with a building stock of 150 houses and intensive use of shallow geothermal energy in Cologne, Germany.  To simulate heat losses from buildings, different scenario analyses with houses of varying insulation standards are performed using a building physics software. Obtained results were then implemented into a groundwater flow model to evaluate the impact on underground temperatures over time and compared with measured data of the same area. Simulation results reveal that the geothermal heating activities impact the groundwater temperatures more than the monitoring data suggests.

How to cite: Hastreiter, N. and Vienken, T.: An innovative temperature monitoring approach to ensure the sustainable use of shallow geothermal energy on quarter scale, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11801, https://doi.org/10.5194/egusphere-egu22-11801, 2022.