Geothermal resources,especially hot dry rock(HDR),hold the unparalleled potential to decarbonize energy systems and bolster the global clean energy transition.Despite five decades of development,enhanced geothermal sy...Geothermal resources,especially hot dry rock(HDR),hold the unparalleled potential to decarbonize energy systems and bolster the global clean energy transition.Despite five decades of development,enhanced geothermal systems(EGS)remain constrained by limited power generation capacity,obstructing the commercial viability of deep geothermal energy.A comprehensive understanding of the limitations throughout the system operation is crucial for facilitating large-scale commercial utilization of HDR geothermal energy.Here,we compare the drilling-enhanced geothermal system(D-EGS)and the excavation-enhanced geothermal system(E-EGS)regarding reservoir construction and heat extraction,identifying a critical bottleneck:D-EGS suffers from non-reproducible fractured reservoir construction due to its dependence on site-specific geology,while E-EGS overcomes this by creating universally adaptable caved thermal reservoirs through mining technologies.We further propose a groundbreaking Tiered Synergistic Mining of Geothermal Energy and Minerals(TSMGM)framework,which integrates conventional mining techniques with EGS to extract HDR and mineral resources simultaneously.By stratifying resources into low-(<50°C),medium-(50–100°C),and high-temperature(>100°C)stages,TSMGM facilitates sequential extraction of both geothermal energy and minerals,significantly reducing operational costs and environmental risks.Although the TSMGM confronts substantial scientific and technical barriers,its modular design and tiered temperature-gradient exploitation strategy may advance HDR energy commercialization and enable integrated multi-energy development,positioning TSMGM as a potential catalyst for global carbon neutrality efforts.展开更多
A comprehensive thermo-economic model combining a geothermal heat mining system and a direct supercritical CO_(2) turbine expansion electric power generation system was proposed in this paper.Assisted by this integrat...A comprehensive thermo-economic model combining a geothermal heat mining system and a direct supercritical CO_(2) turbine expansion electric power generation system was proposed in this paper.Assisted by this integrated model,thermo-economic and optimization analyses for the key design parameters of the whole system including the geothermal well pattern and operational conditions were performed to obtain a minimal levelized cost of electricity(LCOE).Specifically,in geothermal heat extraction simulation,an integrated wellbore-reservoir system model(T2Well/ECO_(2)N)was used to generate a database for creating a fast,predictive,and compatible geothermal heat mining model by employing a response surface methodology.A parametric study was conducted to demonstrate the impact of turbine discharge pressure,injection and production well distance,CO_(2) injection flowrate,CO_(2) injection temperature,and monitored production well bottom pressure on LCOE,system thermal efficiency,and capital cost.It was found that for a 100 MWe power plant,a minimal LCOE of$0.177/kWh was achieved for a 20-year steady operation without considering CO_(2) sequestration credit.In addition,when CO_(2) sequestration credit is$1.00/t,an LCOE breakeven point compared to a conventional geothermal power plant is achieved and a breakpoint for generating electric power generation at no cost was achieved for a sequestration credit of $2.05/t.展开更多
基金supported by the National Natural Science Foundation Project(51627804)the Projects of Talents Recruitment of GDUPT(XJ2022000801)+1 种基金the Science and Technology Plan of Maoming(2023034)the Project of Guangdong Provincial Higher Education Institute(24GYB45).
文摘Geothermal resources,especially hot dry rock(HDR),hold the unparalleled potential to decarbonize energy systems and bolster the global clean energy transition.Despite five decades of development,enhanced geothermal systems(EGS)remain constrained by limited power generation capacity,obstructing the commercial viability of deep geothermal energy.A comprehensive understanding of the limitations throughout the system operation is crucial for facilitating large-scale commercial utilization of HDR geothermal energy.Here,we compare the drilling-enhanced geothermal system(D-EGS)and the excavation-enhanced geothermal system(E-EGS)regarding reservoir construction and heat extraction,identifying a critical bottleneck:D-EGS suffers from non-reproducible fractured reservoir construction due to its dependence on site-specific geology,while E-EGS overcomes this by creating universally adaptable caved thermal reservoirs through mining technologies.We further propose a groundbreaking Tiered Synergistic Mining of Geothermal Energy and Minerals(TSMGM)framework,which integrates conventional mining techniques with EGS to extract HDR and mineral resources simultaneously.By stratifying resources into low-(<50°C),medium-(50–100°C),and high-temperature(>100°C)stages,TSMGM facilitates sequential extraction of both geothermal energy and minerals,significantly reducing operational costs and environmental risks.Although the TSMGM confronts substantial scientific and technical barriers,its modular design and tiered temperature-gradient exploitation strategy may advance HDR energy commercialization and enable integrated multi-energy development,positioning TSMGM as a potential catalyst for global carbon neutrality efforts.
基金funded by the Mexican National Council of Science and Technology(CONACYT in Spanish),under the Sectorial Fund for Energy Sustainability,CONACYT-Secretaiy of Energy(No.S0019-2012-04).
文摘A comprehensive thermo-economic model combining a geothermal heat mining system and a direct supercritical CO_(2) turbine expansion electric power generation system was proposed in this paper.Assisted by this integrated model,thermo-economic and optimization analyses for the key design parameters of the whole system including the geothermal well pattern and operational conditions were performed to obtain a minimal levelized cost of electricity(LCOE).Specifically,in geothermal heat extraction simulation,an integrated wellbore-reservoir system model(T2Well/ECO_(2)N)was used to generate a database for creating a fast,predictive,and compatible geothermal heat mining model by employing a response surface methodology.A parametric study was conducted to demonstrate the impact of turbine discharge pressure,injection and production well distance,CO_(2) injection flowrate,CO_(2) injection temperature,and monitored production well bottom pressure on LCOE,system thermal efficiency,and capital cost.It was found that for a 100 MWe power plant,a minimal LCOE of$0.177/kWh was achieved for a 20-year steady operation without considering CO_(2) sequestration credit.In addition,when CO_(2) sequestration credit is$1.00/t,an LCOE breakeven point compared to a conventional geothermal power plant is achieved and a breakpoint for generating electric power generation at no cost was achieved for a sequestration credit of $2.05/t.
