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Favorable conditions for geothermal energy were created in Türkiye during its neotectonic episode from Neogene to Quaternary. This episode is characterized mainly by fluvio-lacustrine sedimentation and strike-slip tectonics with associated magmatism. Under these conditions, a great number of geothermal areas have formed in the neotectonic provinces in association with major tectonic features, including the North and East Anatolian Fault Zones (NAFZ and EAFZ, respectively). Today, the geothermal resources of Türkiye are mainly located in the West Anatolian Extensional Province associated with the graben systems. However, the Central Anatolian Ova Neotectonic Province is considered one of the most promising geothermal targets which are characterized by the presence of widespread hot dry rock systems. This study mainly aims to throw light on the possible potentiality of these resources at Kırşehir Block by emphasizing the neotectonic evolution of the country. [ABSTRACT FROM AUTHOR]

Geothermal energy is a natural resource that can be utilized directly or by converting to other types of energy. Considering the diversity of the geological structure of Türkiye, the geothermal systems have developed depending on young tectonic and volcanic active rock. Western and Central Anatolia are especially rich in geothermal resources. The geothermal well with the hottest wellbottom temperature was drilled in Central Anatolia, and the well-bottom temperature was measured as 341°C at a depth of 3845 meters. In 2022, Türkiye's electricity generation capacity and the total installed direct heat use reached 1663 MWe and 5113 MWt, respectively. Considering Anatolia's Curie depth and heat flux, the probable thickness of the batholith can be regarded as 10 km. For example, the total granitoid area of Western Anatolia is 4221 km2 and at least 2% of this granitoid can provide approximately 8x107 MWh of electricity by Enhanced Deep Geothermal Systems (EDGS). When all granites in Türkiye are considered, it is expected that the future capacity of Türkiye will be much higher with drilling research and development studies and the discovery of new fields. This capacity will exceed 100.000 MWt levels in the medium term, especially with the addition of EDGSs. [ABSTRACT FROM AUTHOR]

Knowledge of heat flow density on the Earth's surface and subsurface temperature distribution is essential for the interpretation of several processes in the crust such as for the evaluation of the geothermal potential of a region. With this study, we investigate the conductive heat flow distribution in western Anatolia to understand the thermal state and its relationship to regional tectonics in the region. The new heat flow data are collected and combined with previously published data to obtain the new heat flow map of western Anatolia. Analysis of data sets after appropriate corrections yields a better picture of the regional distribution of heat flow within the region. Generally, high values are observed around the grabens of Menderes Massif due to the intense tectonic activity. We also present the 2D steady-state thermal model of Gediz. The modeled temperatures are validated by temperature measurements from two deep wells. Numerical simulation results show that the dominant heat transfer mechanism in Gediz graben can be explained by conduction. Temperature distribution in the deep subsurface of the graben is controlled by both thickness distribution and thermal properties of the different stratigraphic sections. Thermal conductivity contrast between different stratigraphic sections causes anomalously elevated heat flow values at the edges of the graben. The comprehensive results of this study will bring a new perspective to geothermal studies in particular Enhanced Geothermal Systems (EGS) resource estimations in Gediz graben. [ABSTRACT FROM AUTHOR]

• A 3D THM coupled model for both hydraulic fracturing and heat extraction in hot dry rock. • The enhancement in permeability of the hydraulic fracturing stimulated fracture network can be demonstrated in this model. • The hydraulic fracturing and heat extraction over 10 years were carried on the planned Dikili EGS in Turkey. • The optimized re-injection rate was determined at 100 L/s with the average thermal capacity of 31.75 MWth. Geothermal energy attracts extensive attention for its excellent features like large capacity and lack of dependency on weather conditions. This paper presents a development of numerical model to study the hydraulic fracturing and heat extraction from geothermal reservoir, especially from brittle hot dry rock (HDR) reservoir. In this numerical model, an anisotropic damage model has been introduced based on Thermal-Hydraulic-Mechanical (THM) coupling code THOUGH2MP-FLAC3D and this damage-permeability model has also been integrated to demonstrate the enhancement in permeability of stimulated fracture network. Furthermore, numerical studies on planed Dikili enhanced geothermal system (EGS) were carried out by using newly developed model. As the simulated results show, a roughly circular fracture network is created, wherein simulated reservoir volume and area reaches to 49 million m3 and 1.41 million m2, respectively. The maximum permeability increases from initial permeability of 4 × 10−18 m2 to 7.52 × 10−14 m2 in z-direction. Based on these results, heat extraction calculations are performed for 10-years at different injection rates. The accumulated amount of produced net energy increases with the rising injection rate, while growth rate of the average thermal capacity over 10-year slows down. The production results suggest that an injection rate of 100 L/s can recover approximately 1.00 × 1016 J of thermal energy of over a 10-year period, with an average thermal capacity of 31.75 MWth. [ABSTRACT FROM AUTHOR]

As a developing country, Turkey's sustainable development objectives converge on robust and sustainable economic development. The increase in its energy and electricity demand is attributed to the growth of population, urbanization, and industrialization parallel to economic and social growth. Instead of fulfilling the obligation to protect the environment arising from international agreements and achieving desired sustainable development, the dependency on imported fossil fuel in electrical energy production and energy-intensive economic growth results in intensified CO2 emission as well as ironically negative economic output. Therefore, Turkey is forced to exploit its indigenous sources such as coal (which unfortunately increases atmospheric Green House Gas "GHG" emissions) and renewable resources. However, high GHG emission - mainly CO2 - of Turkey's coal power plants impairs deployment of indigenous sources for power generation. Indeed, there is a necessity of technical approaches for higher heat extraction efficiencies and mitigation of high concentration of energy-related CO2 emission. Admittedly, "Carbon Capture, Utilization, and Storage (CCUS)" employing conventional hydrothermal resources offers highly efficient heat extraction, geological CO2 sequestration, and utilization of CO2 for power generation rather than considering CO2 as an effluent. Although there are research gaps and lack of field scale experiment, the economic and environmental viability of implementing CCUS in Turkey can be improved by pilot or field scale projects whereby the presence of these projects commences technological and experimental advances in capturing CO2 either from geothermal power plants or indigenous coal power plants, transporting it to the proven geothermal geologic site, and generating power. Apart from this, the "CO2 - Plume Geothermal Systems (CPG)" compared to unconventional and conventional geothermal systems would commit vigorous potential for continual improvement in economic feasibility of CCUS without a guaranteed return on power generation investments in Turkey. Hence, legislations concerning incentives in CCUS would foster further improvements in the deployment of geothermal resources to pursue sustainable development in Turkey. [ABSTRACT FROM AUTHOR]