Enhanced geothermal systems: A critical review of recent advancements and future potential for clean energy production

The U.S. Department of Energy estimates that utilizing just 0.1% of Earth's geothermal resources could meet global energy demands for millennia. Enhanced Geothermal Systems (EGS) have emerged as a promising technology for sustainable energy production, offering significant potential for clean, renewable heat extraction from deep geothermal reservoirs. However, challenges persist, including high initial costs, drilling and reservoir management complexities, and concerns about induced seismicity. This review paper comprehensively analyzes recent advancements in EGS for sustainable energy production. The paper provides an overview of geothermal resources worldwide and their development, emphasizing the importance of reservoir engineering, heat extraction mechanisms, and advanced geophysical imaging techniques in EGS. It discusses advancements in drilling technologies, such as directional and slim-hole drilling, and novel stimulation techniques like hydraulic fracturing, chemical stimulation, and thermal stimulation. The paper also explores thermal management strategies like downhole heat exchangers and engineered geothermal reservoirs to maximize energy extraction efficiency and minimize operational challenges, enhancing EGS system performance. The review concludes by exploring ongoing challenges and future research directions in EGS development. This work provides valuable guidance for researchers, engineers, and policymakers pursuing sustainable geothermal energy solutions to achieve zero emissions and contribute to the clean energy transition. © 2024