The division on Energy, Resources, and the Environment (ERE) of the European Geosciences Union (EGU) follows an interdisciplinary approach. This volume of Advances in Geosciences presents papers covering key themes from recent developments, beside others, in geothermal systems, critical raw materials, carbon cycle dynamics and renewable energy integration, emphasizing the role of interdisciplinary research in overcoming technical, economic, and societal challenges.

Energy systems across the globe are evolving to meet climate mitigation targets. This requires rapid reductions in fossil fuel use and much more renewable generation. Renewable energy is dependent on the weather. A consequence of this is that there will be periods of low renewable energy production, driven by particular weather conditions. We look at the weather conditions during these periods and show the Indian energy sector could prepare for these events out to 14 days ahead.

The AGEMERA project (Agile Exploration and Geo-Modelling for European Critical Raw Materials) enhances EU critical raw materials exploration by integrating non-invasive methods such as ambient noise passive seismic, drone-based surveys, and muography. These technologies map bedrock properties and resource distribution effectively, feeding data into a comprehensive web-based repository for strategic analysis.

Concepts of High-Temperature Aquifer Thermal Energy Storage (HT-ATES) are investigated for system application in the German Molasse Basin. We quantify via physics-based numerical modelling the system performance with respect to HT-ATES concept development and provide a predictive analysis of HT-ATES application in the Upper Jurassic reservoir. Results demonstrate a non-uniform layer-specific distribution of the thermal front propagation, while promising heat recovery efficiencies are predicted.

Understanding how the electricity generation sector reacts to climate change while large shares of wind and solar energies are introduced is of crucial importance to ensure a clean, secure and affordable electricity provision. We find that in a best case scenario, if we account only for climate change impacts on the wind and solar resource coupled to the demand, then climate change tends to have no adverse economic impacts, while it becomes more interesting to invest in solar than wind energy.

The prevailing view in the scientific community is that large amounts of carbon dioxide (CO₂) from the atmosphere and highly radioactive waste must be disposed of safely. In that regard, studies on natural processes that extend over thousands of years help to assess the long-term behaviour of deep geological repositories. From a purely scientific point of view, CO₂ storage and final disposal of highly radioactive waste are feasible.

The Iceland Deep Drilling Project (IDDP) aims to investigate utilization of supercritical fluids. These fluids are considered to provide 10x more energy compared to conventional geothermal wells. During the IDDP-2 well stimulation, casing at about 2300 m depth was damaged and therefore the discharging fluid comes mainly from this depth instead of depths at higher temperature. The chemical composition of the discharge is, however, indicating minor contribution from the deeper depths.

Dealing with the sociotechnical system of nuclear waste needs an integrated perspective. Its global blockage is due to the neglect of relevant issues. The concept of sustainability (passive protection & control) suggests itself as a reference, enabling a stepwise analysis of dimensions: beyond the triad of ecological/economical/social, also temporal, spatial, technical, political, ethical. The proposal avoids simple complexity reduction, either “technical” or “social fix” (volunteers first). 

To accelerate the heat transition in Germany the ArtemIS project focuses on the geothermal assessment of medium-depth reservoirs on a region-wide basis, covering all geological play types based on structural and numerical reservoir models. The results are incorporated into the GeotIS internet platform to create interactive “heat transition profiles”, which provide all necessary technical and subsurface data for each play type to perform preliminary geothermal assessment studies.

The world needs a shift from fossil fuels, and geothermal energy is a clean energy source. Aquifer thermal energy storage (ATES) system is an example of a shallow geothermal resource. This study estimates the porosity of the Permo-Triassic Sherwood Sandstone Group for ATES system using borehole nuclear magnetic resonance (BNMR) and Petrophysical models. This study confirms storage capacities in the lower Sherwood Sandstone Group of Northern Ireland that make it suitable for ATES systems.

We develop a simplified model which describes the geological geometry of the Vendenheim site, the solid and fluid properties were adapted from studies in the area. We implement compute the hydrothermal flow with a temperature dependent density and viscosity in a porous medium, in order to verify if a hydrothermal convective system is compatible with known observations at the Vendenheim site, and to get a better idea of the initial conditions of a model for an induced seismicity model. 

Storm Daria was a severe winter storm that crossed northern Europe on 25–26 January 1990 with large damage costs and fatalities.  A literature review is presented of societal damage and the interruption of energy and transport networks.  Met-ocean data is analyzed to see if there might have been rogue wave strikes in the North Sea.  This includes careful analysis of tide gauge data from stations around the North Sea as well as available offshore wave measurements and maritime accidents.   

Future glaciations can affect the long-term safety of deep geological repositories for nuclear waste. This study introduces a simple method to assess frequency and duration of ice sheets over the next one million years at locations with past glaciations. The method considers uncertainties in human-caused CO₂ emissions and climate change. It is easy to implement for any nuclear waste management organization that need to consider impacts of future ice sheets on long-term safety.

This paper presents a surrogate modelling approach applied to a geochemical system of uranium sorption on clay, relevant for the safety assessment of nuclear waste repositories. The surrogate uses knowledge about the underlying process to recursively partition the dataset into regions of reduced dimensionality. It achieves high accuracy with a competitive prediction throughput, and is a promising method to speedup  computationally demanding coupled reactive transport models.

This study reveals new insights to the behaviour of subsurface water flow in fractured bedrock which has important implications for environmental safety of geological storage of spent nuclear fuel, carbon sequestration and other unwanted substances. It shows the relevance of accounting for small scale fracture heterogeneity in models to make accurate predictions on the transit times and pathways water flow takes through bedrock.

Salt weathering is influenced by factors such as salt type, concentration, moisture, temperature, and material properties. Environmental conditions and microbial activity can further impact this process. Experimental studies on bacteria in porous systems face challenges from environmental chemistry, detector components, and contamination. Adapting rules and procedures is essential for accurately assessing bacterial activities in salt-bearing porous systems.

To operate aquifer thermal energy storages in a sustainable way, we located an artesian aquifer other than the aquifer storage in a research wellbore by analyzing the subsurface temperature as monitored with a fiber optic cable in three artesian flow tests. The positioning of the artesian aquifer was validated via numerical modelling. Analyses of the temperature data and numerical modelling enabled determining the profile of flow velocity, flow rate and the depth interval of inflow.

We examined how water quality in aquifers and streams varies along the Besòs catchment, and changes in streams during wet and dry periods. Analysis of water quality data (2013-2023) in open databases shows nutrients and salinity increase towards the outlet, and more markedly during dry periods. Since such dry periods may become more frequent with climate change in this Mediterranean basin, this highlights the importance of controlling pollution sources affecting water quality and availability.

This study explores how rock salt reacts to hydrogen, aiming to support safe underground storage of renewable energy. Lab tests on samples from a potential salt cavern-type site in Spain showed that hydrogen caused no major changes to the rock. Minor effects were limited and did not impact overall stability. These findings help confirm that storing hydrogen in salt formations is a safe and reliable option for future energy systems.

The safe disposal of nuclear waste requires consideration of future developments in nature on the repository, like for instance glacifications. We show an approach by using a sophisticated database for a systematic consideration of such developments and their possible interactions.

The effect of spatial variability on uranium diffusion in Opalinus Clay over a million years was assessed by 2D reactive transport simulations. Different rock types and porosity impacted results, with variability's influence growing with longer correlation lengths of geostatistical simulations (up to 12.9 %). This highlights that 1D models may underestimate uncertainty in long-term radionuclide transport at repository sites, and spatial variability must be considered.