Geothermal Resource Potential Research Articles

Morphotectonics of Mount Rendingan Area Related To the Appearances of Geothermal Surface Manifestations

DOI: 10.17014/ijog.6.3.291-309The researched area is situated at Mount Rendingan and its surrounding area, Lampung Province, the southern part of Sumatra Island. It has a big potential of geothermal resource in line with a unique graben like bowl landform and geothermal surface manifestations. This research was carried out using remote sensing and field observation methods. The remote sensing method used topography and Shuttle Radar Topography Mission -Digital Elevation Model (SRTM-DEM) maps to analyze morphotectonic attributes, and the result was validated by morphotectonic data analysis from field observation. The purpose of this research is to evaluate the relation between morphotectonic and the appearances of geothermal surface manifestations. The interpretation of SRTM-DEM and topographic maps are supported by morphotectonic analyses,which indicate that the geothermal surface manifestations in this area are controlled by tectonic activity. It has various levels of lift which are shown by the values of valley height weight ratio (Vf) from 0.16 to 3.31 and the values of mountain front sinuosity (Smf) from 1.05 to 2.09. The morphotectonic characteristics can describe the geological structure activity levels which are reflected in the landform and its rock. The volcanic areas consist of igneous rocks which have small primary permeabilities. However, the development of geological structure can cause fractures in the rock that step in as a medium for passing geothermal fluid from depth to surface. They are found on the fault intersection zone system trending NE-SW and NW-SE, NNE-SSW and NNW-SSE, and WE system directions that indicate the fault system is correlated with the appearances of geothermal manifestations.

Heat energy conversion on applied technology of geothermal energy direct utilization

Indonesia has a high geothermal energy resource, preserved in many fields. But not all geothermal fields are potential for indirect utilizations such as for electric power generation. A direct utilization of a low potential geothermal energy resource has been performed at Batukuwung geothermal field, Serang, West Java. A simple design of vegetable grain dryer has been created and constructed using galvanized metal pipes. A reduction of temperature from 63,1 degrees Celsius at the heat source to 41,5 degrees Celsius at the dryer tool through galvanized metal pipes is quite adequate for vegetable grain drying purposes. It is quite a prospect simple technology to be applied and developed in Indonesia as a geothermal energy country having various vegetable grain products from various plants such as coffee, corn, peanut and many other tropical plantations.

Radiogenic heat production variations in the Gonghe basin, northeastern Tibetan Plateau: Implications for the origin of high-temperature geothermal resources

Hot dry rock is an almost inexhaustible source of geothermal energy. Since the first attempt to extract thermal energy from hot dry rock in America in the 1970s, successive studies have been conducted in many countries. Recently, high-temperature rock (exceeding 180 °C) was drilled in the Gonghe basin, northeastern Tibetan Plateau, marking a significant breakthrough in the exploration of hot dry rock resources in China. A proper understanding of the origin of the hot dry rock in the Gonghe basin is essential to the evaluation of the geothermal resource potential and to the establishment of an enhanced geothermal system in the basin.In the present research, we attempt to seek clues from the radiogenic heat production of the rocks. In all, 52 core samples collected from the main boreholes in the Gonghe basin were measured for the concentrations of radioisotopes. The heat production values were determined to be 1.21–2.02 μW m−3 for the sedimentary rocks, yielding an arithmetic mean of 1.67 ± 0.29 μW m−3, and 1.17–5.81 μW m−3 for the basal granitic rocks, yielding a mean of 3.20 ± 1.07 μW m−3. The results show that the radiogenic heat production of the granitic rocks is approximately that of global Mesozoic-Cenozoic granites, which is further corroborated by an extensive compilation of heat production data for granitic rocks in the immediate vicinity of the study area (average of 2.07 ± 0.97 μW m−3, n = 136). Based on the heat production data sets combined with available geological and geophysical information, the crustal heat production contribution is determined. The results show that the heat contribution from the crust is about 48.3 mW m−2, accounting for ∼47.3% of terrestrial heat flow. Compared with the regional background heat flow, the high heat flow in the Gonghe basin may be attributed to an additional heat flow contribution (∼27 mW m−2) from a heat anomaly (probably related to partial melting) at shallow depth, which is evidenced by the low-resistivity anomalies in the magnetotelluric survey results. Thus, this study emphasizes that the anomalous heat flow and the hot dry rock geothermal resources in the Gonghe basin may be the combined effects of the radiogenic heat contribution from the thickened crust and the heat contribution from a local heat anomaly beneath the Gonghe basin.

Origin and fate of hydrothermal fluids at Piton des Neiges volcano (Réunion Island): A geochemical and isotopic (O, H, C, Sr, Li, Cl) study of thermal springs

As many ocean basaltic volcanoes worldwide, Piton des Neiges (Réunion Island) hosts a hydrothermal system that represents a potential geothermal resource. Despite several prospection campaigns over the past decades, this potential has never been confirmed because many aspects of fluid supply and circulation remain unclear. To track the origin and fate of hydrothermal fluids, we analyzed the geochemistry of thermal springs (water and gas), by combining conventional tracers (major-trace elements and O, H, C, Sr, Li isotopes) with Cl isotopes, a geochemical tool under development. Added to literature data, our new results allow us to compare the composition of thermal springs with cold waters, rocks, gas, and fumarolic deposits from La Réunion and elsewhere, and to untwine the complex history of fluid mixing that constitutes the geothermal system of Piton des Neiges.δ18OH2O and δDH2O values of springs (-8.67 to -4.9 and -56.3 to -23.5 ‰ VSMOW, respectively) are positioned close to the local meteoric water line, showing that thermal waters are of meteoric origin. However, their depletion in heavy isotopes relative to cold waters suggests a recharge strongly influenced by cyclones, with a possible contribution from high altitude (≥ 2000 m) rainfalls. Their absence of 18O enrichment relative to the local meteoric water line indicates that the isotopic exchange between rocks and water is very limited, and therefore suggests that their deep temperatures are relatively low and/or the water/rock ratios are high. δ13C values in thermal waters (-8.0 to +3.2 ‰ PDB) and gases (-6.7 to -5.3 ‰ PDB) confirm that carbon is essentially of magmatic origin, which we interpret as supplied by regional degassing of La Réunion hotspot. Major-trace elements and 87Sr/86Sr (0.704142 to 0.704336), δ7Li (+2 ‰ and +34.8 ‰ LSVEC), and δ37Cl (-0.35 ‰ and +0.40 ‰ SMOC) compositions show that three additional processes contribute to the mineralization of thermal waters: 1) interaction with basalt at temperatures ≥50 °C, 2) very limited seawater contamination (< 3 mol%), and/or 3) leaching of trachyte or scrubbing of fumarolic gas or condensates emitted by a shallow trachytic magma in the volcanic edifice.The geothermal system of Piton des Neiges is thus the result of meteoric water interaction with a trachytic heat source (as a solidified intrusion or a magma pocket), unrelated to the CO2 flux. We also emphasize that thermal waters at Piton des Neiges are exceptionally isolated from seawater compared to other geothermal systems in ocean island volcanoes worldwide, which implies a heat source located above the seawater/freshwater interface. These inferences are of critical importance for the future geothermal exploration on the island, as they suggest that the geothermal resource is within reach of relatively shallow drilling depths (≤1000 m).

STUDI IDENTIFIKASI KUALITAS AIR DAN JENIS IKAN AIR TAWAR DI SUMBER AIR PANAS DESA NYELANDING KABUPATEN BANGKA SELATAN SEBAGAI DASAR PENGELOLAAN POTENSI KAWASAN AIR PANAS UNTUK KEGIATAN PERIKANAN DAN WISATA

Hot springs in Nyelanding Village, South Bangka Regency, have the potential of geothermal resources that can be used as a potential energy source, moreover found several types of freshwater fish that utilize these hot springs as their natural habitat. The objectives of this study are to identify the water quality and diversity of freshwater fish species in the hot spring area of Nyelanding Village, South Bangka Regency; analyze the feasibility of water quality for fisheries and tourism activities; and analyzing fish growth patterns found at these locations. The results showed that there were two types of fish found in the hot springs of Nyelanding Village, which were Gabus Fish (Channa striata) and Sepat Fish (Trichogaster trichopterus). There are 6 hot water quality parameters Village Nyelanding included in standard class II PP 82 of 2001 include pH, COD, TSS, TDS, Nitrate and Total fospat, two parameters are not required (depth and ammonia), one parameter (temperature ) not in normal natural waters. The growth pattern of Gabus Fish in the hot water of Nyelanding Village is negative allometric with a growth coefficient of 2.076. In general, based on the analysis of water quality parameters, the Nyelanding Village hot water is suitable for biota life as well as aquaculture activities and tourist areas. For aquaculture, the recommended type of fish is eurythermal. However, their habit of draining the hot water pool Village Nyelanding made towards development of the area is less recommended for fishing activity, but preferably as a tourist area.

An improved volumetric method of geothermal resources assessment for shallow ground combining geophysical data

Assessment of available heat capacity in the shallow ground is important to the development of ground source or geothermal heat pumps. A new volumetric method-based approach is proposed for evaluating shallow geothermal potential by combining microtremor survey results. Parameters such as thickness of clay and sandy gravel layers can be achieved by processing the microtremor filed data. The study area was divided into grids based on the different exploration sites. The heat present in each small unit was calculated using the revised volumetric method. This division into small units improved the accuracy of assessment of the geothermal potential and helped plot the distribution map of the available heat amount, which indicated optimal locations for development and utilization of shallow geothermal resources. Jimo, China was used as an example to depict the calculation flow. Since the microtremor survey method can identify the thickness of clay, sandy gravel, and fresh bedrock layers in shallow ground, the amount of shallow geothermal resources present above fresh bedrock was calculated. In Jimo, the amount of exploitable geothermal resources, using the traditional volumetric method, was found to be 4.92 × 1012 kJ. The proposed calculation method not only provided a higher corresponding value of 6.96 × 1012 kJ but also showed the regions with the highest potential of shallow geothermal resources. Hence, this approach provides an alternative method for geothermal potential assessment which can be used globally.

Hydrogeochemical characteristics and formation of the hot springs occurring in the plunging ends of an anticline in Chongqing, Eastern Sichuan Basin, China

Hot springs occurring in two plunging ends of a very long and narrow anticline is unique. This study focuses on the hydrogeochemical characteristics and formation of the anticline-controlled thermal groundwater which may provide a perspective for geothermal resources potential. The low-to-middle temperature thermal groundwater of the Taozidang anticline in the Sichuan Basin, China, was examined to estimate the temperature of the deep reservoir and identify the main hydrogeochemical processes affecting the composition of hot water during circulation and evolution. The occurrences of thermal groundwater of these springs strongly controlled by anticline are in the two plunging ends of the anticline and differ from that of the more common deep-fault circulation controlled by faults or by faults and anticlines. Incongruent dissolution of the gypsum or anhydrite of the Lower Triassic Jialingjiang and Middle Triassic Leikoupo Groups is affected by the anticline structures and results in hot water of SO4–Ca type. Meteoric water infiltrates through the karst channels and fissures at the outcropping area of carbonates to feed the groundwater. Part of the groundwater flows to depth and circulate along the two flanks of the anticline after heated. It issues in the form of hot springs or wells in the plunging ends of the anticline. Another part of the groundwater undergoing a shallow circulation forms the normal temperature spring near the hot springs. This study of the anticline-controlled thermal groundwater is important for exploitation and utilization of geothermal energy (tourism) and provides a perspective for the anticline-controlled geothermal resources potential.

Power Production Estimates from Geothermal Resources by Means of Small-Size Compact Climeon Heat Power Converters: Case Studies from Portugal (Sete Cidades, Azores and Longroiva Spa, Mainland)

Renewable forms of energy are increasingly penetrating the electricity market, particularly, geothermal energy. A wide range of resource temperatures and fluid quality are converted mostly using traditional binary power plants and, recently, using Climeon modular units. Portuguese natural geothermal resources are far from precise estimations. Despite the parameter uncertainties, electric power resource estimations of two natural geothermal reservoirs are presented: a volcanic sourced heated high-enthalpy geothermal reservoir in Sete Cidades, São Miguel Island, Azores; and a low-enthalpy geothermal reservoir linked to a fractured zone in a granitic setting in Longroiva, in the northern part of the Portuguese mainland. Based on the volumetric method, we assessed the power potential of geothermal resources in Sete Cidades and Longroiva using a probabilistic methodology—Monte Carlo simulation. The average reserve estimations for Climeon module were 5.66 MWe and 0.64 MWe for Sete Cidades and Longroiva, respectively. This figure was by far higher when compared to traditional binary technology; those differences were mostly attributed to distinct conversions efficiency factors.

Terrestrial heat flow evaluation from thermal response tests combined with temperature profiling

The terrestrial heat flux density, an essential information to evaluate the deep geothermal resource potential, is rarely defined over urban areas where energy needs are important. In an effort to fill this gap, the subsurface thermal conductivity estimated during two thermal response tests was coupled with undisturbed temperature profile measurements conducted in the same boreholes to infer terrestrial heat flow near the surface. The undisturbed temperature profiles were reproduced with an inverse numerical model of conductive heat transfer, where the optimization of the model bottom boundary condition allows determining the near-surface heat flow. The inverse numerical simulation approach was previously validated by optimizing a steady-state and synthetic temperature profile calculated with Fourier's Law. Data from two thermal response tests in ground heat exchangers of one hundred meters depth were analyzed with inverse numerical simulations provided as examples for the town of Québec City, Canada, and Orléans, France. The temperature profiles measured at the sites and corrected according to the paleoclimate effects of the quaternary glaciations were reproduced with the model. The approach presented offers an alternative to assess heat flow in the preliminary exploration of deep geothermal resources of urban areas, where thermal response tests may be common while deep wells are sparsely distributed over the area to assess heat flow.

Geophysical survey of geothermal energy potential in the Liaoji Belt, northeastern China

The Liaodong area which lies in the Liaoji Belt of northeastern China is rich in geothermal resources, but locating the resources is challenging. Here non-seismic geophysical data, existing geological data and the physical properties of rocks are examined to locate and characterise potential geothermal resources. High-precision gravity, aeromagnetic and magnetotelluric data are analysed to determine the characteristics of the hidden faults in the region and map the spatial distribution of the subsurface rock mass and its properties. The distribution of hidden faults and the basic characteristics of the rock mass were determined via Euler deconvolution of the gravity and aeromagnetic data. The subsurface extension of concealed faults, the spatial distribution of intrusive rocks, and the specific locations of underground thermal storage structures were determined from magnetotelluric data analysis, thereby enabling geothermal energy targets to be identified. The results highlight four potential sites of geothermal energy development in the study area, which indicate that non-seismic geophysical data can provide reliable clues to the geothermal energy potential in a given region.

Assessment of Geothermal Resources in Petroliferous Basins in China

In order to speed up the development and utilization of hydrothermal energy, it is essential to assess the potential of geothermal resources in petroliferous basins. In this paper, the distribution of reservoirs (aquifers) and the characteristics of geothermal fields have been studied systematically based on geological, geophysical, well drilling, temperature, and sample test data obtained from the major petroliferous basins of China. It has been found that some of the porous sandstone formations in these petroliferous basins are major geothermal reservoirs and are extensively thick and widely distributed. In general, the geothermal gradient in China is higher in the eastern basins and lower in the western basins. On average, the geothermal gradient is above 30 °C/km in the Bohai Bay, Songliao, and Subei basins. The geothermal resource abundance is also higher in eastern China and in the Beibuwan basin in southern China, and the geothermal source forming condition is better, followed by the Ordos, Qaidam, and Sichuan basins in Central China. Other potential basins include the Tarim and Junggar basins in western China, where the geothermal gradient ranges between 21 and 22 °C/km, on average. In this paper, three methods, stochastic simulation, unit volumetric, and analogy, were used for the assessment of geothermal resources. Using the stochastic simulation and unit volumetric methods, the geothermal resources, annual recovered geothermal resources, geothermal water resources, and thermal energy of water in 11 basins or blocks of up to 4000 m deep were calculated. Grading evaluation criteria were established by considering the heterogeneity of geothermal reservoirs. The results showed that the petroliferous basins are very rich in geothermal resources. The annual recoverable resources reach 1626.8 × 106 tons of standard coal, in which grade I, grade II, and grade III resources are 641.9 × 106, 298.6 × 106, and 686.3 × 106 tons of standard coal, respectively. The results demonstrate that the development and utilization of geothermal energy in oilfields has a huge potential for industrial production and family use, and a great significance for the development of green oilfields. With the high demand of heat, the eastern oilfields with high geothermal resource abundance should be the first to be considered for the production and utilization of geothermal energy, followed by the central and western oilfields.

Geothermal resource assessment of the Gediz Graben utilizing TOPSIS methodology

The Gediz Graben possesses the second highest geothermal power generation potential in Western Anatolia, Turkey. In this study, the geothermal resource potential of the Gediz Graben has been assessed by following an ideal point methodology. For this purpose, nine criteria layers were introduced into a GIS environment, namely, distance to faults and fault density, distance to cap rock units, hot springs and graben center, Gutenberg-Richter b-value map, night-time surface temperature, NDVI and slope. Each layer was weighted by using the pairwise comparison method. Then, an ideal point methodology, namely, Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) was used to rank the geothermal favorability of the Gediz Graben from most favorable to least favorable. In order to assess the success of the geothermal favorability map, a comparison of the favorability classes with the known producing well data revealed that 76% of the wells fell within the highest two favorability classes where none of the wells were located in the least two favorable classes.

Joint inversion of gravity and surface wave data constrained by magnetotelluric: Application to deep geothermal exploration of crustal fault zone in felsic basement

Geophysical exploration in unconventional geothermal reservoir is challenging because of the lack of structures with specific geophysical signature such as a clay cap above volcanic geothermal reservoirs. The combination of several geophysical methods such as magnetotelluric (MT), gravity and seismic methods provides complementary insight into the geothermal reservoir. We present a joint inversion approach of ambient noise surface wave and gravity constrained by the 3D distribution of electrical resistivity. The method is applied to analyze the potential of unconventional deep geothermal resources in the French Massif Central (FMC). We coupled the resistivity, density and shear wave velocity with a linear correlation. We characterized the common properties in relation to the geological domains down to about 10–15 km. We validated the proposed approach on a synthetic model derived from models obtained from each independent geophysical method. The joint inversion limited the non-uniqueness of the gravity and the ambient noise tomography inversion and allow to recover the features of the synthetic models. We applied the method to real field data acquired in the Sioule Valley, Massif Central, France. The joint features observed in the geophysical models suggest a deep heat source associated with a possible shallow (∼6–8 km) brittle–ductile transition. A large fault zone, the Pongibaud Fault zone, seems to become listric and connect the surface to this transition zone to possibly constitute a permeable path for water circulation.

Systematic Analysis of Geothermal Resources in the Coastal Bedrock Area of Chunxiao Town (China) by Using Geochemistry and Geophysics Methods

Geochemical and geophysical investigations were carried out to obtain more evidence of the potential of geothermal resources in Chunxiao Town (China). Hydrochemical data indicate the possible existence of mixing process between deep geothermal water and shallow groundwater. Analysis with SiO2 geothermometer shows that the geothermal reservoir temperature was estimated around 40–60 °C. In addition, combination investigations with CSAMT, radioactive radon, and soil thermal-released mercury detection reveal the specific location of the conduction fractures for thermal water circulation. Furthermore, the drilling work shows the deep thermal water temperature of &gt;55 °C and the thermal water yield of 300 m3/d. All these results could provide important guidance for the scientific exploration and effective utilization of geothermal resources in coastal area.

Remote Sensing Contribution to The Identification of Potential Geothermal Deposits: A Case Study of The Moroccan Sahara

Abstract Geothermal energy refers to any heat stored, naturally, in the earth's crust and is considered as renewable, ecological, universal and sustainable energy. In Morocco, geothermal energy is not yet exploited, neither considered, to support the institutional energy mainly focused on solar and wind energy. However, modest researches and some interventions related to geothermal resources were led and conducted by few Moroccan university. Remote sensing is a preliminary prospection tool for geothermal research allowing to face the lack of valuable data constraint and also the absence of officially credible data which will allow us to successfully complete our study. The main purpose of this research is to locate potential geothermal resources in the Moroccan Sahara using remote sensing and geospatial technologies. A set of satellite images (MODIS, ASTER and Landsat) were used and were completely processed and analyzed. Furthermore, significant indices were calculated from satellite images to prospect for potential deposits, namely diurnal and nocturnal surface temperature, hydrothermal alteration indices and lineaments density layer. This study allowed us to detect nocturnal thermal anomalies in the locality of Tichla. The statistical analysis showed a strong correlation between the intensities of the different indices in the prospected area of Tichla. Therefore, this significant concordance leads us to conclude that this locality has a strong potential for geothermal reservoirs. important tool for the preliminary identification of potential geothermal energy deposits.

Hot dry rock geothermal resource potential in the Wudalianchi volcanic field, NE CHINA: Implications from geophysical exploration

Hot dry rock is regarded as the clean energy of the future and is an important part of geothermal resources, with great research value and development prospects. The Weishan volcano, located in the northern part of the Wudalianchi volcanic group, was formed in the Pleistocene, and its age is only (0.57–0.31) ± 0.05 Ma. This area has a geothermal setting similar to but a younger age than that of the Fenton Hill volcano (formed 1.40–1.10 Ma) where a hot dry rock power project has operated since 1973. In this study, we used ambient noise tomography and magnetotelluric sounding methods to investigate deep heat sources beneath the Weishan volcano. The results show good geothermal conditions for hot dry rock formation in this region. A cooling magma chamber that might be the hot dry rock heat source is indicated in the upper crust at 6.5–13 km depth, with a volume of ∼200 km3. Our study suggests that the monzonitic granites of the Indosinian Xiaohongshan unit, which lies beneath the Late Cretaceous Nenjiang Formation and the Neoproterozoic-Early Cambrian Beikuanhe Formation, should be the main target for further hot dry rock geothermal energy exploration and development.

Geothermal Energy Reconnaissance of Southeastern Nigeria from Analysis of Aeromagnetic and Gravity Data

Given the daunting energy challenges currently bedeviling Nigeria, with demand for electrical power exceeding availability, alternative energy sources (preferentially renewable) are vigorously considered. This is the first study to examine geothermal energy prospects in southeastern Nigeria with the ultimate aim of locating and mapping regions of shallow Curie point depths (CPDs), crustal thickness, and geologic structures supportive of a geothermal system. We estimated CPD using the spectral analysis technique on magnetic field anomalies. Gravity anomalies were subjected to a series of procedures to assess geological structures. Result reveals deeper CPDs within central and southern regions of Okposi, Afikpo and Biase towns in an approximate range of 18.4 to 19.3 km. Shallow CPDs (9.8–17.4 km) have also been obtained within Obubra and Abakaliki regions. Estimated crustal thickness (Moho) ranges between 26.5 and 35.8 km. Part of the region with shallow CPD correlates with regions of shallow Moho depths, particularly in Abakaliki, and deeper Moho depths coincide with deeper CPD estimates at the Afikpo location. The estimated geothermal gradient and heat flow values range between 29.0 and 45.0 oC and 52.2–101.5 mW/m2, respectively, and fall within values evaluated from deep wells drilled for oil exploration within the adjoining Anambra Basin region. This study recommends the regions with shallow depths for possible geothermal power plant location. Gravity data evaluations also reveal significant subsurface intrusions within Ugbodo, Obubra and Abakaliki locations. Overall, this study is a step forward toward a better evaluation of the geothermal energy resources potential of southeastern Nigeria.

Economic appraisal and scoping of geothermal energy extraction projects using depleted hydrocarbon wells

This study offers a first step in examining a potential solution for what to do with the ever-increasing number of horizontal shale wells in the United States (and lately, Argentina and China), as they come to the end of their economic life. A comprehensive decision-making tool was developed for scoping assessments based on the technical and economic appraisal of abandoned hydrocarbon wells repurposed into enhanced geothermal systems. We specifically target near end-of-life oil and gas wells, re-commissioned to extract geothermal energy as opposed to hydrocarbons, because these potential geothermal resources are prevalent near a handful of major US population and energy demand centers, including Pittsburgh, Houston, Denver, Dallas, Oklahoma City and San Antonio. This study addresses some of the technical challenges associated with such projects. However, the main focus is on (1) the probabilistic evaluation of the economic net present value, and (2) specific solutions for possible commercial deal structures required for negotiation and project implementation. The backdrop for the test case in this study is the new Texas A&M RELLIS Campus being constructed in College Station, Texas. A successful commercial model for the use of abandoned oil and gas wells to extract low and medium temperature geothermal resources could spur further development and a pilot study is proposed for this green source of energy. Our estimations suggest a net present value of $1.2 billion could be unlocked in the US alone, through the repurposing of wells, previously used for hydrocarbon extraction only.

Research of the spatial aspects of using renewable energy sources for sustainable development of the territory

The object of research is renewable energy sources as the basis for the development of renewable energy in Ukraine. Problems in the implementation of objects in this industry are the need to apply measures for their safe operation and less profitability of renewable energy sources compared to traditional ones. This is due to the high cost of equipment and significant costs to ensure technological processes. Increasing the share of renewable energy sources in the total energy balance will require government subsidies to the industry. It has been proven that the application of the cartographic approach allows determining the optimal locations of renewable energy facilities from an economic point of view and taking into account a number of equally important factors, in particular, social and environmental impact. The next methods are used: cartographic – when applying modeling techniques for building maps of renewable energy resources; geo-informational – in the process of collecting and processing information about resources, objects and factors for the development of renewable energy; statistical – at the stage of calculating the energy potential of wind energy, solar energy, geothermal and hydrological resources. The maps for the above-mentioned renewable energy directions are presented, recommendations on the optimal areas for the construction of energy facilities are given on the example of Kharkiv region (Ukraine). So, location: wind power plants are recommended in Vovchansk, Kharkiv, Velykyi Burluk regions; solar power plants – in Blyzniuky, Pervomaiskyi, Balakliia, Izium, Lozova and Borova; geothermal power plants – in the south of Barvinkove and Blyzniuky, southeast of Izium, Borova and Lozova districts. Perspectives for locating small hydropower stations within the study area are sections of the Siverskyi Donets, Udy, Berestova, Mzha, Merla rivers. The dependence of the economic efficiency of wind, solar, geothermal energy and small hydropower facilities on factors such as: distance of transportation of energy raw materials and finished energy to consumers; heat loss; cost of investment in the construction of infrastructure (power lines, electrical substations, heating networks).

Three-Dimensional Seismic Velocity Structure of the Aegean Region of Turkey from Local Earthquake Tomography

This study brings new insights to elucidate the 3-D seismic velocity structure of the Aegean region of Turkey by using Local Earthquake Tomography (LET). The study area has remarkable potential for geothermal resources. To provide the subsurface geological structure of seismogenic layers and geothermal areas, we develop new high-resolution depth-cross sections through Buyuk Menderes, Kucuk Menderes and Gediz grabens. Travel times of almost 265.000 readings (14.963 P-phase and 11.969 S-phase picks) from 2.085 well-located events recorded between 2007 and 2016 by a permanent seismic network of 75 broad-band seismometers were used to precisely interpret the 3-D Vp (lithological) and Vp/Vs (petrological) models of the study area. We detected four main layers down to 35-40 km depths with different Vp velocities ranging from 3.5 to 8.5 km/s. Mid-crustal interface (Conrad discontinuity) is discovered at 15 km depth in nearly all depth-cross-sections. Our results suggest an average of 25 km Moho depth in the Aegean region of Turkey. The depths range from around 18 km beneath SE of Aydin to 29 km beneath Aliaga, and approximate values of 19, 25 and 31 km beneath the Doganbey, Kutahya and Selendi-Demirci regions, respectively. The geothermal areas of the studied region are imaged by Vp and Vp/Vs anomalies. We propose the Aliaga, Denizli, Doganbey and Kosk areas as low Vp, low Vp/Vs anomalies which are an indicator of steam, CO2 or a mixture of both. Low Vp, high Vp/Vs models, suggesting geothermal fluids, are clearly visible near the Buharkent, Gumuskol, Guzelhisar, Kosk, Kuyucak, Saraykoy and Suzbeyli regions. We also report that the Bademler, Candarli, Kalekoy, Karahalli, Merdivenli, Ortakoy, Saruhanli, Yelki and Yuntdagikoseler regions might be good candidates for new potential geothermal resources.