Marija Macenić, Tomislav Kurevija^*, Tin Herbst

Energy Engineering, Vol.123, No.1, 2026, DOI:10.32604/ee.2025.067067 - 27 December 2025

Abstract The increased interest in geothermal energy is evident, along with the exploitation of traditional hydrothermal systems, in the growing research and projects developing around the reuse of already-drilled oil, gas, and exploration wells. The Republic of Croatia has around 4000 wells, however, due to a long period since most of these wells were drilled and completed, there is uncertainty about how many are available for retrofitting as deep-borehole heat exchangers. Nevertheless, as hydrocarbon production decreases, it is expected that the number of wells available for the revitalization and exploitation of geothermal energy will increase. The… More >

Yongwei Li¹, Kaituo Jiao^2,*, Dongxu Han³, Bo Yu², Xiaoze Du¹

CMES-Computer Modeling in Engineering & Sciences, Vol.145, No.3, pp. 3453-3479, 2025, DOI:10.32604/cmes.2025.073239 - 23 December 2025

Abstract The permeability contrast between the Hot Dry Rock (HDR) reservoir and the surrounding formations is a key factor governing fluid loss in Enhanced Geothermal Systems (EGS). This study thus aims to investigate its impact on system performance under varying operating conditions, and a three-dimensional thermo–hydro–mechanical (THM) coupled EGS model is developed based on the geological parameters of the GR1 well in the Qiabuqia region. The coupled processes of fluid flow, heat transfer, and geomechanics within the reservoir under varying reservoir–surrounding rock permeability contrasts, as well as the flow and heat exchange along the wellbores from… More >

Feng He^*, Rui Tan, Songlian Jiang, Chao Qian, Chengzhong Bu, Benqiang Wang

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.10, pp. 2557-2577, 2025, DOI:10.32604/fdmp.2025.070186 - 30 October 2025

Abstract This study introduces a Transformer-based multimodal fusion framework for simulating multiphase flow and heat transfer in carbon dioxide (CO₂)–water enhanced geothermal systems (EGS). The model integrates geological parameters, thermal gradients, and control schedules to enable fast and accurate prediction of complex reservoir dynamics. The main contributions are: (i) development of a workflow that couples physics-based reservoir simulation with a Transformer neural network architecture, (ii) design of physics-guided loss functions to enforce conservation of mass and energy, (iii) application of the surrogate model to closed-loop optimization using a differential evolution (DE) algorithm, and (iv) incorporation of economic… More >

Orkhan Jafarli^*

Energy Engineering, Vol.122, No.9, pp. 3595-3608, 2025, DOI:10.32604/ee.2025.067982 - 26 August 2025

Abstract This study investigates the feasibility and efficiency of geothermal energy for heating applications in Azerbaijan, with a specific focus on the Khachmaz region. Despite the country’s growing interest in sustainable energy, limited research has addressed the potential of ground-source heat pump (GSHP) systems under local climatic and soil conditions. To address this gap, the study employs GeoT*SOL simulation to evaluate system performance, incorporating site-specific parameters such as soil thermal conductivity, heating demand profiles, and regional weather data. The results show that the GSHP system achieves a maximum seasonal performance factor (SPF) of 5.62 and an… More >

Yuze Xue¹, Li Kou^2,3, Guosheng Jia^4,*, Liwen Jin⁴, Zhibin Zhang⁴, Jianke Hao⁴, Lip Huat Saw^5,*

Energy Engineering, Vol.122, No.3, pp. 1005-1024, 2025, DOI:10.32604/ee.2025.059198 - 07 March 2025

Abstract Geothermal energy, a form of renewable energy, has been extensively utilized for building heating. However, there is a lack of detailed comparative studies on the use of shallow and medium-deep geothermal energy in building energy systems, which are essential for decision-making. Therefore, this paper presents a comparative study of the performance and economic analysis of shallow and medium-deep borehole heat exchanger heating systems. Based on the geological parameters of Xi’an, China and commonly used borehole heat exchanger structures, numerical simulation methods are employed to analyze performance and economic efficiency. The results indicate that increasing the… More > Graphic Abstract

Weitao Zhang¹, Dongxu Han^2,*, Yujie Chen², Tingyu Li³, Liang Gong^1,*, Bo Yu²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.30, No.1, pp. 1-2, 2024, DOI:10.32604/icces.2024.011484

Abstract As climate change accelerates due to fossil fuel use, geothermal energy emerges as an indispensable renewable solution 1. Hot dry rock (HDR) reservoirs, accounting for more than 90% of total geothermal resources 2, have gained wide attention worldwide for their abundant reserves, wide distribution, and carbon-free, stable, and efficient supply characteristics 3. While HDR geothermal energy offers significant potential, its development faces challenges, including the complex interaction between fluid flow, heat transfer, reactive solute transport, and the rock’s mechanical processes, referred to as the THMC coupling process 4. Cracks, ubiquitous in HDR geothermal reservoirs, exhibit… More >

Abdul Sattar Laghari¹, Mohammad Waqas Chandio¹, Laveet Kumar^2,*, Mamdouh El Haj Assad³

Energy Engineering, Vol.121, No.8, pp. 2023-2038, 2024, DOI:10.32604/ee.2024.051082 - 19 July 2024

Abstract The selection of working fluid significantly impacts the geothermal ORC’s Efficiency. Using a mixture as a working fluid is a strategy to improve the output of geothermal ORC. In the current study, modelling and thermodynamic analysis of ORC, using geothermal as a heat source, is carried out at fixed operating conditions. The model is simulated in the Engineering Equation Solver (EES). An environment-friendly mixture of fluids, i.e., R245fa/R600a, with a suitable mole fraction, is used as the operating fluid. The mixture provided the most convenient results compared to the pure working fluid under fixed operating More >

Chia-Nan Wang, Thuy-Duong Thi Pham^*, Nhat-Luong Nhieu

Energy Engineering, Vol.121, No.8, pp. 2039-2064, 2024, DOI:10.32604/ee.2024.050224 - 19 July 2024

Abstract Geothermal energy is considered a renewable, environmentally friendly, especially carbon-free, sustainable energy source that can solve the problem of climate change. In general, countries with geothermal energy resources are the ones going through the ring of fire. Therefore, not every country is lucky enough to own this resource. As a country with 117 active volcanoes and within the world’s ring of fire, it is a country whose geothermal resources are estimated to be about 40% of the world’s geothermal energy potential. However, the percentage used compared to the geothermal potential is too small. Therefore, this… More >

Hao Qi¹, Mohamed Sharaf², Andres Annuk³, Adrian Ilinca⁴, Mohamed A. Mohamed^5,*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.2, pp. 1387-1404, 2024, DOI:10.32604/cmes.2024.048672 - 20 May 2024

Abstract Hot dry rock (HDR) is rich in reserve, widely distributed, green, low-carbon, and has broad development potential and prospects. In this paper, a distributionally robust optimization (DRO) scheduling model for a regionally integrated energy system (RIES) considering HDR co-generation is proposed. First, the HDR-enhanced geothermal system (HDR-EGS) is introduced into the RIES. HDR-EGS realizes the thermoelectric decoupling of combined heat and power (CHP) through coordinated operation with the regional power grid and the regional heat grid, which enhances the system wind power (WP) feed-in space. Secondly, peak-hour loads are shifted using price demand response guidance More >

Md Nahin Mahmood^*, Boyun Guo

Energy Engineering, Vol.120, No.12, pp. 2707-2720, 2023, DOI:10.32604/ee.2023.042996 - 29 November 2023

Abstract The energy industry faces a significant challenge in extracting natural gas from offshore natural gas hydrate (NGH) reservoirs, primarily due to the low productivity of wells and the high operational costs involved. The present study offers an assessment of the feasibility of utilizing geothermal energy to augment the production of natural gas from offshore gas hydrate reservoirs through the implementation of the methane-CO₂ swapping technique. The present study expands the research scope of the authors beyond their previous publication, which exclusively examined the generation of methane from marine gas hydrates. Specifically, the current investigation explores the… More >