Geothermal Research Articles

Experimental research of convective heat transfer between nanofluids and high-temperature dense granite in deep geothermal reservoirs

Global warming is increasing as CO2 emissions from the use of conventional fossil fuels continue to rise. The development of geothermal energy is gradually becoming the key to the sustainable development of human society in the future. Enhancing the heat transfer performance of circulating heat transfer fluids is one of the effective means to efficiently exploit deep geothermal resources. In this study, a self-developed circulating heat exchange experimental setup was established. The convection heat transfer characteristics of nanofluids in high-temperature rocks were experimentally investigated. Al2O3 nanofluid and CuO nanofluid were used as the working medium for heat transfer in high temperature granite samples. The effects of the Reynolds number (1000–6000) and parameters such as nanoparticle type (CuO & Al2O3), size (20 nm & 40 nm) and mass fraction (0 wt%-2wt%) on the heat transfer intensity were analyzed. The effect of nanoparticle accumulation on the rock surface on the local heat transfer strength was also investigated. The results indicate that the increase of Reynolds number enhances the heat transfer strength of nanofluids in rocks. Nanofluid containing 20 nm Al2O3 nanoparticles has better heat transfer performance in rock than nanofluid containing 20 nm CuO nanoparticles. Meanwhile, the heat transfer performance of nanofluid containing 20 nm Al2O3 nanoparticles in rock is better than that of nanofluid containing 40 nm Al2O3 nanoparticles. The heat transfer intensity increases and then decreases as the nanoparticle mass fraction increases. The heat transfer coefficient at Reynolds number 6000 is 52.2 % higher than that of water. For nanofluids and water, the local heat transfer intensity decreases with increasing distance from the inlet. Meanwhile, accumulation of nanoparticles on rock surfaces during convective heat transfer enhances heat transfer intensity. The results show that nanofluids have the potential to be applied to deep geothermal resource extraction. This paper provides data and technical support for the application of nanomaterials in medium and deep geothermal systems to enhance heat transfer efficiency.

Geothermal energy for sustainable and green energy supply in the future

Geothermal energy for sustainable and green energy supply in the future

Biofuel processing in a closed-loop geothermal system

Closed-loop geothermal systems (CLGS) provide a renewable heat source for district heating and electricity production. However, high capital costs can be a barrier to these applications. This study finds that the high pressures (>8MPa) and temperatures (>240°C) attained by working fluid inside the loop present additional opportunities: driving supercritical reactions that produce biodiesel from fatty acids. A new design for a subsurface geothermal reactor is proposed, enabling biofuel processing underground without the need for conventional processing equipment (pump, heater, reactors, and heat exchangers) or fossil fuel as energy source. To analyze the feasibility of this approach and its environmental and economic effects, a computational model that incorporates the simultaneous effects of flow dynamics, heat transfer, and reaction kinetics is developed. The application of CLGS is concluded to reduce the CO2 intensity of the resulting biodiesel by up to 33%. A geothermal-driven biofuel reactor could yield up to 95% fatty acid methyl esters. Additional sensible heat carried by the products can be redirected to electricity generation or district heating. The relevant requirements and optimal operating conditions for this approach to biofuel synthesis are identified. A technoeconomic analysis shows CLGS-based biofuel production cost can be comparable to natural gas-based production (∼840 $/ton). It also indicates return-on-investment after five years and highlights the most suitable locations that combine proximity to appropriate feedstocks and subsurface conditions. Integrated biodiesel production and energy extraction provides an alternative route to harnessing geothermal energy.

Dynamic management of ground thermal response uncertainty through temporal analysis of parameter sensitivity

Accurately estimating the dimensionless ground thermal response factor (g-function) is critical for the design and operation of geothermal energy systems. This process, however, is fraught with uncertainties stemming from the difficulty in controlling on-site geometric parameters and estimating thermal properties through field experiments. The relative contributions of these parameters to response uncertainty change temporally as the response progresses. Thus, understanding this temporal sensitivity variation is crucial for effective response uncertainty management. To address this, we conducted transient global sensitivity analyses. Regardless of borefield setups, ground thermal properties were key factors in thermal response uncertainty. However, their influence decreased from the late-mid term as borehole radius and borehole distance became more significant in single-borehole and multi-borehole setups, respectively. This time-varying relative sensitivity suggests that prioritizing parameters to reduce response uncertainty depends on the temporal characteristics of the ground load. To demonstrate this, we systematically halved the uncertainty for each parameter and examined the resultant change in the fluid temperature uncertainty for a dynamic ground load scenario. Notably, prioritizing parameters with high early-response sensitivity significantly reduced fluid temperature uncertainty. These findings highlight the need for dynamic uncertainty management strategies in geothermal system design and operation. For dynamic load profiles utilizing the ground as a heat source or sink, prioritizing parameters with high sensitivity in the early- to mid-term is crucial. Conversely, for long-term storage applications, focusing on parameters with high sensitivity in the mid- to long-term response becomes essential.

Model for dimensioning borehole heat exchanger applied to mixed-integer-linear-problem (MILP) energy system optimization

This paper introduces three novel approaches to size geothermal energy piles in a MILP, offering fresh perspectives and potential solutions. The research overlooks MILP models that incorporate the sizing of a geothermal borefield. Therefore, this paper presents a new model utilizing a g-function model to regulate the power limits. Geothermal energy is an essential renewable source, particularly for heating and cooling. Complex energy systems, with their diverse sources of heating and cooling and intricate interactions, are crucial for a climate-neutral energy system. This work significantly contributes to the integration of geothermal energy as a vital energy source into the modelling of such complex systems. Borehole heat exchangers help generate heat in low-temperature energy systems. However, optimizing these exchangers using mixed-integer-linear programming (MILP), which only allows for linear equations, is complex. The current research only uses R-C, reservoir, or g-function models for pre-sized borefields. As a result, borehole heat exchangers are often represented by linear factors such as 50 W/m for extraction or injection limits. A breakthrough in the accuracy of borehole heat exchanger sizing has been achieved with the development of a new model, which has been rigorously compared to two simpler models. The geothermal system was configured for three energy systems with varying ground and bore field parameters. The results were then compared with existing geothermal system tools. The new model provides more accurate depth sizing with an error of less than 5 % compared to simpler models with an error higher than 50 %, although it requires more calculation time. The new model can lead to more accurate borefield sizing in MILP applications to optimize energy systems. This new model is especially beneficial for large-scale projects that are highly dependent on borefield size.

An insightful multicriteria model for the selection of drilling technique for heat extraction from geothermal reservoirs using a fuzzy-rough approach

Geothermal energy stands out as an exceptional renewable resource for power generation, offering a consistent power production without the intermittency issues. Despite its potential to deliver a consistent supply of electricity on demand, geothermal adoption is hindered due to substantial costs. Utilising the most effective drilling method can alleviate this challenge by boosting efficiency and reducing operational costs. The primary goal of this study is to identify the best drilling method for extracting heat from geothermal reservoirs. This optimised approach facilitates better access to geothermal reservoirs, leading to increased heat recovery rates and improved project viability. Traditional methods often fall short in evaluating optimal drilling alternatives due to uncertainties. To address this, our research introduces an innovative paradigm that integrates novel T-Spherical Hesitant Fuzzy Rough (T−SHFR) set, method for the removal effects of criteria with a geometric mean and ranking alternatives with weights of criterion hybrid Multiple Criteria Decision-Making (MCDM) techniques. By leveraging the novel T−SHFR concept, our approach allows for a comprehensive assessment of various factors. This holistic evaluation ensures an exhaustive comprehension of the decision-making environment. The study reveals that reservoir characteristics play a significant role in selecting a sustainable drilling alternative. Furthermore, directional drilling appears as the most promising method with higher energy yields followed by slim hole drilling. The robustness and credibility of these findings are established through sensitivity and comparative analyses, indicating the potential applicability of this MCDM method to analogous challenges in different contexts. The findings of the ranking techniques were validated using Spearman's rank correlation coefficient, which revealed a positive and notable correlation. This research will empower stakeholders to make informed decisions, thereby enhancing the overall efficiency and sustainability of geothermal energy projects.

The optimization of a low-temperature geothermal-driven combined cooling and power system: Thermoeconomic and advanced exergy assessments

Switching from fossil fuels to geothermal energy can provide a solution to environmental issues and the energy crisis caused by power and cooling generation systems. In this regard, this study examines an innovative cogeneration system that utilizes low-temperature geothermal energy to generate power and cool the built environment simultaneously. The proposed system incorporates a Kalina-34 cycle, complemented by an integrated absorption refrigeration cycle. System analysis encompasses thermodynamic and exergoeconomic assessments, as well as parametric investigations to gauge the effects of critical parameters on system performance. Following a parametric study, the TOPSIS multicriteria decision-making technique is applied to optimize turbine inlet pressure, vapor generator temperature difference, and ammonia concentration. Finally, the main source of irreversibility is compared by conventional and advanced exergy analyses under optimal conditions. Results show that under optimal conditions, the energy utilization factor (EUF), exergy efficiency, and unit co-generation cost (UCGC) are 11.15 % (30.5 % improvement), 45.54 % (20.1 % improvement), and 6.04 $/GJ (1.63 % reduction), respectively. Furthermore, while conventional exergy analysis prioritizes the improvement of the condenser-1, vapor generator, and turbine in that order, advanced exergy analysis suggests a different priority order, with condenser-1, turbine, and vapor generator being the main objects of improvement, respectively. Implementing this study will significantly improve and optimize the proposed system.

Resurgent dome and super-hot enhanced geothermal system: The Sahinkalesi Massif within the Hasandag Stratovolcanic Province, Central Anatolia, Turkey

The Sahinkalesi, a volcanic dome located NNE of Hasandağ, Türkiye exhibits anomalous heat flow value, geothermal gradient and the Curie point depth is located at very shallow depth in this region. Our investigation indicates presence of super-critical thermal regime (378°C) at about 4 km depth and the MT analysis indicate shallow magma chamber at about 5 km depth. The crust is relatively thin below this region with the low-velocity region located at depth of about 36 km. Thermo-Hydro-mechanical model investigation has been carried out using finite element discretization technique. For faulted zone reservoir models, 30 years of geothermal energy exploitation does not cause thermal breakthrough for mass flow rates up to 500 kg/s, however, the mean stress developed in the reservoir becomes much larger and may be unsustainable for the reservoir stability. To ensure the success of a fractured reservoir model, the use of multiple wellbores is recommended. In the case of a closed-loop geothermal system, the primary concern is the control of thermoelastic stress. This can be achieved either by increasing the wellbore depth while reducing the injection mass flow rate, or by extending the wellbore's horizontal component. The outlet temperature in both the cases maintained at 275°C. This is the first time a superhot EGS site has been identified in Türkiye.

Enhancing structural strength and water retention of crosslinked polyacrylamide gel with the T-ZnOw

Crosslinked polyacrylamide gel serves as an effective plugging material, crucial for preventing water/gas channeling in reservoirs and enhancing the swept volume and oil recovery. However, its practical application encounters a significant challenge in maintaining long-term stability of strength and volume, particularly under high temperatures. This study investigates the reinforcement of polyacrylamide gel with three-dimensional (3D) nanomaterials, specifically tetra-needle-like zinc oxide whiskers (T-ZnOw), to enhance its structural stability and bound water content. The stress sweep tests showed that the addition of 0.15 wt% T-ZnOw increased the maximum elastic modulus of the gel to 28.5 Pa, representing a 51.2 % improvement compared to before the addition. After 60 days of high-temperature aging at 130 °C, the T-ZnOw strengthened gel still maintained an elastic modulus of 21.8 Pa. With increasing T-ZnOw concentration, the yield point of the gel increased from 4.74 Pa to 9.57 Pa, the anti-deformation of the gel has significantly increased. The stability test results in high salinity water indicate that at a salinity of 150,000 mg/L, the dehydration rate of the strengthened gel is less than 5 %, with an elastic modulus retention rate exceeding 88 %. Furthermore, thermodynamic testing confirms the enhanced thermal degradation resistance and water retention capacity of the gel. Under reservoir temperature conditions, the T-ZnOw strengthened gel exhibits a weight loss of less than 3 %. Additionally, the inclusion of T-ZnOw results in an increase in the bound water capacity index from 4.65 to 12.28. In conclusion, the integration of T-ZnOw into the polyacrylamide gel network not only enhances its mechanical performance and water retention under high-temperature conditions but also demonstrates superior stability in high-salinity environments. This innovative material shows significant potential for improving oil recovery rates in high-temperature reservoirs and can be applied to other high-temperature underground scenarios such as geothermal development and CO2 utilization and storage.

Application to novel smart techniques for decarbonization of commercial building heating and cooling through optimal energy management

The present article proposes a novel smart building energy system utilizing deep geothermal resources through naturally-driven borehole thermal energy storage interacting with the district heating network. It includes an intelligent control strategy for lowering operational costs, making better use of renewables, and avoiding CO2 emissions by eliminating heat pumps and cooling machines to address the heating and cooling demands of a commercial building in Uppsala, a city near Stockholm, Sweden. After comprehensively conducting techno-environmental and economic assessments, the system is fine-tuned using artificial neural networks (ANN) for optimization. The study aims to determine which ANN design and training procedure is the most efficient in terms of accuracy and computing speed. It also assesses well-known optimization algorithms using the TOPSIS decision-making technique to find the best trade-off among various indicators. According to the parametric results, deeper boreholes can collect more geothermal energy and reduce CO2 emissions. However, deep drilling becomes more expensive overall, suggesting the need for multi-objective optimization to balance costs and techno-environmental benefits. The results indicate that Levenberg-Marquardt algorithms offer the optimum trade-off between computation time and error minimization. From a TOPSIS perspective, while the dragonfly algorithm is not ideal for optimizing the suggested system, the non-dominated sorting genetic algorithm is the most efficient since it yields more ideal points rated below 100. The optimization yields a higher energy production of 120 kWh/m2, as well as a decreased levelized cost of energy of 57 $/MWh, a shorter payback period of two years, and a reduced CO2 index of 1.90 kg/MWh. The analysis reveals that despite the high investment costs of 382.50 USD/m2, the system is financially beneficial in the long run due to a short payback period of around eight years, which aligns with the goals of future smart energy systems: reduce pollution and increase cost-effectiveness.

Opportunities and Challenges of Geothermal Energy: A Comparative Analysis of Three European Cases—Belgium, Iceland, and Italy

Opportunities and Challenges of Geothermal Energy: A Comparative Analysis of Three European Cases—Belgium, Iceland, and Italy

Geothermal Resource Assessment and Development Recommendations for the Huangliu Formation in the Central Depression of the Yinggehai Basin

As a renewable resource, geothermal energy plays an increasingly important role in global and regional energy structures. Influenced by regional tectonic activities, multi-stage thermal evolution, and continuous subsidence, the subsurface temperatures in the Yinggehai Basin has been consistently rising, resulting in the formation of multiple geothermal reservoirs. The Neogene Huangliu Formation, with its high geothermal gradients, suitable burial depths, considerable thickness, and wide distribution, provides excellent geological conditions for substantial geothermal resources. However, the thermal storage characteristics and geothermal resources of this formation have not been fully assessed, limiting their effective development. This study systematically collected and analyzed drilling, geological, and geophysical data to examine these reservoirs’ geometric structures, thermal properties, and physical characteristics. Further, we quantitatively evaluated the geothermal resource potential of the Huangliu Formation and its respective reservoirs through volumetric estimation and Monte Carlo simulations, pointing zones with high geothermal prospects and formulating targeted development strategies. The findings indicate: (1) The Yinggehai Basin exhibits an average geothermal gradient of 39.4 ± 4.7 °C/km and an average terrestrial heat flow of 77.4 ± 19.1 mW/m2, demonstrating a favorable geothermal background; (2) The central depression of the Huangliu Formation harbors considerable geothermal resource potential, with an average reservoir temperature of 140.9 °C, and a total geothermal resource quantified at approximately 2.75 × 1020 J, equivalent to 93.95 × 108 tec. Monte Carlo projections estimate the maximum potential resource at about 3.10 × 1020 J, approximately 105.9 ×108 tec. (3) Additionally, the R14 and R23 reservoirs have been identified as possessing the highest potential for geothermal resource development. The study also proposes a comprehensive utilization model that integrates offshore geothermal power generation with multiple applications. These findings provide a method for the evaluation of geothermal resources in the Yinggehai Basin and lay a foundation for the sustainable development of resources.

The role of pit lake thermal dynamics on the thermal performance of ground heat exchangers

The addition of ground heat exchangers (GHEs) to a pit lake’s basin has the potential for abundant, clean and renewable geothermal energy extraction using shallow geothermal systems. Basin-embedded GHEs avoid direct interaction with mine water, which has been shown to impact efficiency and longevity in mine open-loop geothermal systems negatively. The now accelerated closure of open-pit coal mines presents itself as an opportunity to use this technology. However, no guidelines currently exist for designing or operating GHEs embedded in the sediment of water bodies. Furthermore, the two-way coupling between the complex annual thermal fluid dynamics that lakes are naturally subjected to and heat fluxes on the sediments and the GHE system has not been explored. In this study, we develop and validate finite element models to assess the relevance of lake thermal stratification in the performance of a geothermal system embedded in water bodies basins, e.g., on open-pit mine closures, under temperate residential thermal loads. The results show that the pit lake’s role as a thermal sink improves significantly when the lake’s thermal dynamics are accounted for, with an increase of up to 292% in the lake’s available energy budget. A minor variation in energy budget (~8%) was found whether the lake is modelled explicitly or simplified as a transient Dirichlet temperature boundary condition. This small difference vanishes if horizontal circulation along the lake is considered, highlighting the lake’s thermal energy potential. Finally, the impact on the GHE Coefficient of Performance (COP) is evaluated, with a maximum of ~15% difference among all cases.

Optimizing a hybrid solid oxide fuel cell-gas turbine and geothermal energy system for enhanced efficiency and economic performance in power and hydrogen production scenario

Geothermal energy is utilized due to its sustainability and ability to provide a continuous low-emission source of heat, making it an ideal complement to the high-efficiency requirements of modern power plants. This study investigates a novel configuration coupling a solid oxide fuel cell-gas turbine unit with a dual-flash binary geothermal structure, enhanced by low-temperature electricity generation and hydrogen production subsystems. This configuration incorporates a regenerative steam Rankine cycle and a proton exchange membrane electrolyzer to achieve an efficient overall design. The setup is evaluated from thermodynamic and economic perspectives using a non-dominated sorting genetic algorithm-II for optimization. A complete parametric study assesses the sensitivity of critical variables. Multi-objective optimization is conducted across three scenarios considering exergy efficiency, hydrogen production rate, sum unit cost of products, and the payback period as objective functions. Results indicate an optimal exergy efficiency of 56.95% and a hydrogen production rate of 0.22 kg/h, with a product unit cost of $7.06/GJ and a payback period of 1.12 years. The parametric study underscores the significant impact of the number of solid oxide fuel cells and their existing density on key variables of the presented configuration. This study highlights the system's potential for efficient and economically feasible power and hydrogen production.

Applicability of Na/K geothermometer to the metapelitic non-volcanic geothermal fields in the Taiwan orogenic belt

Taiwan is situated at one of the world's most active orogenic belts with arc-continent collision. This event resulted in the burial and uplift of mudstones along the continental margin, transforming them into metapelitic mountains. These mountains intercept rainfall and serve as the driving force for deep water circulation, enabling meteoric fluids to carry residual heat to the surface, thus giving rise to hot springs. The Taiwan orogenic belt is home to over 100 hot springs, and some of the hot spring reservoir temperatures such as Chingshui, Tuchang-Jentse, Lushan, Chihpon, and Chinlun exceeds 160 °C. Geothermal development in Taiwan has been carried out in such hot spring areas without any volcanic activities.In order to assess reservoir temperatures and confirm the applicability of the Na/K geothermometer to such high temperature hot spring system, the concentrations of Na+, K+, and SiO2 were analyzed from geothermal wells. Considering the mineral composition of metapelitic host rock, a new Na/K geothermometer is proposed based on equilibrium between albite and illite:T>180∘C,T(∘C)=2474log(NaK)+3.73−273.15This formula is only applicable in a reducing fluid and does not involve the formation of clay minerals except illite. It also requires several years to reach equilibrium. When using this formula to estimate reservoir temperatures, careful consideration of various conditions is necessary. It is advisable to incorporate both quartz geothermometer and down-hole temperature measurements for a more accurate assessment. Combining the Na/K geothermometer with the quartz geothermometer, along with other geochemical data such as Cl−concentrations and δD and δ18O of fluid, helps to understand whether hydrothermal fluids have undergone evaporation, dilution, and/or mixing processes.

State Policy In The Field Of Alternative Energy Sources In The Conditions Of Ensuring Energy Security Of Ukraine

The article analyses features of state policy in the field of alternative energy sources, particularly replacing traditional energy resources with alternative energy sources, aiming to reduce the energy intensity of Ukraine’s gross domestic product and ensure the state’s energy security. It is noted that Ukraine has significant potential for developing alternative energy sources, particularly wind energy, solar energy, bioenergy, hydropower, and geothermal energy. An analysis of the growth dynamics of the installed capacity of alternative energy source facilities operating under the «green» tariff has shown that solar energy is currently the most developed in Ukraine. This creates a foundation for further development of wind and bioenergy. The main practical benefits of energy storage systems are highlighted, including ensuring electricity supply to businesses when the external grid is disconnected, storing cheap electricity during excess capacity, and supplying it during peak demand when it is more expensive. Additionally, these systems have the potential to support and restore grid frequency. Storing surplus energy from solar power plants can increase the overall efficiency of the energy system. The author identifies the main tasks to be implemented within state policy to ensure energy security. These include investing in the restoration and decentralization of the energy system (increasing the share of electricity production from alternative energy sources, including the construction of wind and solar power plants, as well as energy storage facilities for the development of energy storage technologies produced from renewable sources), building biomethane production capacities, introducing new types of environmentally friendly fuels, increasing the construction of interconnectors with ENTSO-E to integrate Ukraine’s electricity system with the European power grid, enhancing the localization of energy storage systems, implementing innovative and efficient technologies in the electricity distribution sector, including smart grids, microgrids, and «vehicle-to-grid» systems, and resolving issues related to the «green» tariff.

Machine learning-based predictive approach for pitting and uniform corrosion in geothermal energy systems

Geothermal energy is a sustainable source from Earth's crust, and holds great potential for electricity generation, but corrosion poses a significant challenge. In this study, we employed a range of machine learning models, including linear regression, decision tree, k-nearest neighbors, random forest, and support vector regression to predict uniform and pitting corrosion. Despite limited data performance issues, virtual samples from a synthetic data generator improved results when combined with actual data. Fine-tuning with various hyperparameters enhanced model performance, with the decision tree proving the most effective. Exhaustive feature selection identifies key factors influencing uniform and pitting corrosion, validated by the models.

Solastalgia as Disruption of Biocultural Identity. The Mount Amiata Geothermal Conflict

Some residents of Mount Amiata in Tuscany, Italy, are experiencing emotional distress and solastalgia due to changes in their beloved land. Mount Amiata is witnessing protests by citizens’ associations and activists who criticize the alleged social, economic, and environmental sustainability of geothermal energy. The analysis of the environmental conflict around geothermal energy on Mount Amiata contributes to the empirical use of the concept of "solastalgia” as affective rupture of biocultural relationships and identities. In the area surrounding Mount Amiata, the production of geothermal energy is experienced as an attack on the biodiversity of the "Mother Mountain," as a loss of the sense of home, and as part of a "predatory philosophy" employed by ENEL (Ente Nazionale per l’Energia Elettrica, National Electricity Board). This ethnographic study aims to analyze how the transformation of places influences the affective and biocultural identity of their inhabitants.

A state‐of‐the‐art review on geothermal energy exploration in Morocco: Current status and prospects

AbstractIn the last few decades, addressing the global challenge of implementation of strategies for renewable energy and energy efficiency has become crucial. Morocco, since 2009, has made a steadfast commitment to sustainability, with a particular focus on advancing the development of renewable energy resources. A comprehensive strategy has been formulated, centering on utilizing the country's energy potential to drive progress in this vital sector. Morocco is considered a country with abundant thermal water, indicating deep reservoirs with significant hydrothermal potential. Geothermal zones were selected based on the abundance of hot springs where water temperatures were high and geothermal gradients were significant. The abundance and importance of hot springs, combined with recent volcanism and ongoing non‐tectonic activity linked to alpine orogeny, strongly suggest that these regions are promising reservoirs for geothermal energy. This great potential also extends to neighboring countries. In northeast and south Morocco, the temperature of thermal water ranges from 26 to 54°C. This study serves as an inclusive review of the geothermal potentialities in Morocco.

Feasibility study of geothermal assisted energy storage using hydraulic fracturing

Similar to wind and solar energy, geothermal energy, as a renewable energy source that is widely distributed, abundant, green, and low-carbon, has substantial potential. In this study, we introduce and validate the feasibility of a novel approach that employs hydraulic fracturing techniques to store electrical power in hydraulic fractures, while simultaneously extracting geothermal energy from the strata. The primary advantage of this methodology is its dual functionality (i.e., storing energy while harvesting heat). This approach outperforms conventional energy storage methods in terms of efficiency, in which the total energy storage efficiency is far greater than 1. Our study analyzed the factors influencing energy and efficiency, as well as the variations in energy and efficiency under long-term energy storage conditions. This study also provides a theoretical basis for optimizing the design of hydraulic fracturing energy storage assisted by geothermal energy.