Geothermal Systems

The Democratic Republic of Congo (DRC) has a huge and varied renewable and nonrenewable energy potential. It consists of hydroelectricity, timber, oil, coal, gas, solar energy, biomass and geothermal energy. Among others, geothermal potential is very common in the Eastern part of the DRC. The substratum of the Eastern DRC consists of a basement complex with an age varying between Archean and middle Proterozoic. It is covered by upper Proterozoic sedimentary rocks in several areas. These geologic formations are folded in a general northeast direction which, from Kiambi, bends to take a north-south direction. Besides these orogenic movements caused by tangential pressures, the East of the DRC is a beautiful illustration of relatively recent vertical movements, giving raise to the rift valley which is filled up by Phanerozoic sediments. The fractures are often lined by surface and subsurface geothermal manifestations. Hot springs are the most common surface manifestations. They are located in many places of the western branch of the rift in the DRC. Some of them are relatively very hot for the most part and their chemical composition is dominated by the abundant presence of sulphide and salt minerals. They are located in the

The geothermal field of Therma-Nigrita is the most exploited low enthalpy field in Greece. The geothermal waters have a temperature between 40-64οC and they are rich in CO2 content. There are a lot of geothermally heated greenhouses producing vegetables and flowers, and subsurface heating for asparagus cultivation. This paper dwells on the results reached via a cost reduction application of geothermal fluids for commercial production of the Spirulina blue-green alga. The Spirulina biomass has an interesting composition (more than 50% of proteins, vitamins, minerals, essential fatty acids, antioxidants, phycobiliproteins, etc.). This makes it a valuable additive in terms of better nutrition, the human diet and health strengthening. It is also a rich source of biochemical components. Spirulina is cultivated authrophically in plastic-foil-protected production ponds with an area of 1,950 sq.m., and in a suitable nutrition medium. The algal suspension is cultivated with fresh water heated by geothermal waters. The geothermal energy used in this way as well as setting up the cultivation ponds in a greenhouse contribute to increasing the daily yield by 20-30% (spring and autumn), and the cultivation season is prolonged (from March until November). Using freely released geothermal CO2 reduces the technological costs for the production of Spirulina biomass by over 25%. Therefore, the cultivation of Spirulina is an important ergonomic application of geothermal energy in the section of aquaculture.

In this study, the structural controls of a high-temperature system (188 to 287 oC) associated with the detachment fault in Gediz Graben generating approximately half of this electricity generation in Turkey which is in the top five of the world in the generation of electricity from geothermal resources are examined. The high-temperature geothermal reservoirs associated with detachment fault in the study area have formed along the normal faults nearly in E-W orientation and in intensely fractured rocks in a structurally complex manner associated with transfer faults approximately in N-S orientation. Generally, it has been determined that the reservoirs are closely located to strike-slip faults intersecting, overlapping, and/or terminated with Quaternary transfer faults.

For promoting the diffusion of GSHP (Ground Source Heat Pumps) a tool for sizing these systems will be carried out in the H2020 research project named “Cheap GSHPs”. The paper presents the set up of a database with energy profile of a certain amount of buildings representative of the typology (single family houses, block of flats, office buildings) with different insulation levels and in different climatic conditions. Based on the weather analysis among European climatic files, twenty locations have been considered. For each location the overall energy and the mean hourly monthly energy profiles for heating and cooling (sensible and latent) have been calculated. Based on the results, the correlations with Degree Days (DD) for heating and cooling have been found in order to generalize the results to have pre-calculated profiles for sizing GSHP.

Geothermal energy, with associated low-carbon emissions compared to conventional fossil fuels, is presently one of the potential renewable energy sources. The decryption of the chemistry of thermal manifestations of geothermal systems, in terms of relative abundances of various chemical facies, is mandatory before launching systematic geothermal exploration in a given area as it provides valuable information on the basic characteristics of the geothermal reservoir. For the present study, three clusters of hot springs have been selected -1) Shyok-Nubra valleys geothermal prospect in NW Himalaya, 2) Subansiri valley geothermal areas in NE Himalaya and 3) the hot spring system occurring along Munger-Saharsa Ridge Fault Zone (MSRF) in the Eastern part of India. The study of these geothermal systems with low to moderately high temperatures of 35−75°C, has been carried out with two main objectives. The first objective is to estimate reservoir temperature and other characteristics in the t...

The ancient and renowned thermal baths of Aquae Ceretanae recently discovered Guide Tips  Share: I'm thrilled to share with you an exciting surprise that one of our recent site visits during the beautiful sunny days of January unveiled: the rediscovery of the ancient and renowned Aquae Ceretane. These thermal springs are mentioned in various ancient sources, including the Roman physician Caelius Aurelianus, the Greek historian and geographer Strabo, and the ancient Roman historian Titus Livius. The springs had disappeared and remained "frozen" by history for over a millennium and a half, buried beneath private agricultural land, yet they maintained a surprisingly good state of preservation for some of their decorative features. The size and artistic level of these structures are decidedly exceptional compared to the standard of settlements known in the area. With immense pleasure, I discovered that the cleaning operations have resumed in the archaeological excavation of the Aquae Ceretanae, conducted by the Archaeological Group of the Cerite Territory, the same group that has already cleaned and restored the archaeological area of the "Laghetto," part of the UNESCO site of the Banditaccia necropolis in Cerveteri, one of the oldest, largest, and most important areas in the entire Mediterranean. Thanks to the invaluable availability of the scientific coordinator, the renowned archaeologist Flavio Enei, Roberto Della Ceca, and Dr. Monica De Simone, it was possible to access the freshly cleaned excavation site to take some photos and preview video footage. The baths were finally identified at the end of 1986 when, following plowing carried out with a tractor by the landowner, shards and fragments of pottery, marble, glass, and countless mosaic tiles emerged scattered over a large area of that private agricultural field. Archaeologist Dr. Rita Cosentino immediately intervened, who was responsible at the time for the Archaeological Superintendence of Southern Etruria, who realized that they were dealing with a very important site, but did not yet think of the famous Terme Ceretane. With the start of archaeological excavations shortly after, along with other discoveries, marble thresholds emerged, and, at a depth of more than five meters, the remains of two large contiguous rooms were found (dating back to the 1st century but frequented until the 3rd), each equipped with a pool: the one with the larger pool, the calidarium, surrounded by a portico, has a curved end and is still flooded by a high-temperature spring, and a smaller one, the tepidarium, where the pool is rectangular and receives tepid water, surrounded by three rows of marble seats (with prized yellow and Carrara marbles adorning all the baths), part of the mosaics with their respective glass paste tiles in blue, green, yellow, black, and red, and a decisive marble votive pillar inscribed with: "To Jupiter and the sources of the Ceretane waters" indicating its connection to a series of cults related to healing News 

The purpose of this paper is to evaluate the likelihood of outflow of geothermal water to shoreline hot springs at Rajabasa and the implications of this outflow to conceptual models. Two different models have been proposed to explain the chemistry of the Gunung Botak shoreline hot spring; a mixed seawater – geothermal water and purely steam – heated seawater. The steam – heated seawater model is based solely upon a similarity in Cl/B ratios between the springs and seawater, which are much higher than in the usual liquid geothermal system. Hot springs distant from the shoreline show high Cl/B ratio, however, suggesting that this is a characteristic of the system. The model for a mixed seawater – geothermal water origin proposes an elaborate model of boiling, seawater mixing and repeated boiling, which is testable by modelling fumarole gas chemistry. It was found that the majority of the gas chemistry of the inland Way Merak and seaside Gunung Botak fumaroles can be matched with a boi...

Cisempur village is located at the slope of Mount Geulis, having a very variated morphology from gentle slopes to very steep ones. Due to the high demand for settlements the land use change can not be avoided.  The steepness of the slope, the decrease of the number of vegetations, and the increase of load from buildings may induced land slide occurrence.  This problem motivate us to perform measurement at the area, in order to uncover the information about the level of stability and the land carrying capacity, through the study of the subsurface rock layering condition. In this work, we present the shallow resistivity by means of Electrical Resistivity Tomography (ERT) method in two measurement lines. The obtained data is processed using 2D inversion method, in order to obtain the layering structure cross-section. The interpretation of the results suggest the existence of sandstone, which is normally associated with the location of aquifer and tuffaceous clay. The tuffaceous may fun...

Geothermal energy and Aquifer thermal energy storage can provide beneficial ways of storing energy in excess and
providing energy when needed. North Dakota's renewable energy system is impacted by its harsh winters. Geologic aquifer thermal
aquifer storage system is a large scale geothermal system that can act as energy storage media. Aquifer thermal storage systems are
dependent on heat conductivity of rocks, storage capacity of aquifer, fluid flow, geochemistry and geo-mechanics. The goals of the
project are to 1) evaluate the amount of energy that can be stored in deep aquifers; 2) access the amount of energy that is thermally
recoverable; 3) monitor changes in geo-mechanical parameters. CMG STARS, a three-phase multi-component thermal and steam
additive simulator, was used for the thermal numerical simulation which takes into account the geo-mechanics (thermal dilation and
re-compaction). A conventional reservoir with representative porosity and permeability is modelled in CMG and Semi Analytical
Model (SAM) was used to calculate the wellbore dynamics involved with geothermal operations. This is used to calculate heat
transfer to the surrounding formation and determine our heat loss. Our preliminary results show us the reservoir pore volume dilation
re-compaction model changes from cold water injection. The grid block void porosity dilation re-compaction model changes are
greatly influenced by grid block pressure.

Underground water is one of the important component sources for human being. Study on interpretation of underground water flow has been carried out using Geoelectric Schlumberger Electrode Configuration in Labuh Baru Barat Village, Payung Sekaki District, Pekanbaru. The range measurement was chosen to be 240 meter. The output of measurement  arecurrent and voltage. The data, then was inputed into software progress and surfer 11. The output of this computer program is a map of underground waterflow  pettern and underground lithology. The results of mapping of the pattern of underground water flow indicate that the direction of water flow from North to South direction, or from Pinang street to Payung Sekaki street. The thickness of the layer start  from the first layer that is 4.05 meters and 5.4 meters is a layer of silt- clay, the second layer is 13.07 meters and 14.3 meters is a layer of mud stone, the third layer is 13.07 meters and 15.2 meters is a layer of sand and alluvial and ...

Se presenta un mapa geológico, escala 1:50 000 del cuadrante Tapantí, el cual se encuentra en la región central de Costa Rica y forma parte del Cinturón Deformado del Centro de Costa Rica (CDCCR), producto de la interacción de la cordillera de Coco y la región W de la microplaca Panamá. Las rocas más antiguas cartografiadas son miocenas y están representadas por las formaciones sedimentarias Pacacua, Peña Negra, San Miguel y Coris, que forman el borde oriental de la cuenca Candelaria. Se distinguieron 3 eventos magmáticos; el arco volcánico Mioceno, representando por la Formación La Cruz y clastos volcánicos de la Formación Pacacua; un nuevo periodo de actividad ígnea entre 6 Ma y 4,2 Ma, representado por las Formaciones Grifo Alto, Doán y el Intrusivo de Tapantí y, finalmente, se desarrolla el arco volcánico actual, representado por las formaciones Paraíso y Cervantes, con un rango de edad entre los 0,6 Ma y 0,02 Ma. Desde el punto de vista geoquímico, se observa un fuerte cambio e...

espanolLa planificacion del uso geotermico del agua subterranea en acuiferos someros urbanos requiere un modelo numerico capaz de reproducir los efectos de la explotacion actual y ser capaz de predecir los impactos derivados de dicha actividad. En este trabajo se presenta el desarrollo preliminar de un modelo numerico que puede contribuir a mejorar la gestion de los recursos geotermicos someros en la ciudad de Zaragoza. El modelo numerico permite implementar toda la informacion hidrogeologica y termica recopilada, explicar esta informa- cion de forma coherente reproduciendo la fisica de fluidos y termodinamica en medios poroso s y predecir a medio y largo plazo los impactos producidos. Finalmente se muestran las posibilidades y ventajas derivadas del uso del modelo numerico en la gestion de permisos de concesion de derechos de explotacion para nuevos aprovechamientos. EnglishThe management of the thermal use of groundwater in shallow urban aquifers requires a numerical model capable...

espanolLa planificacion del uso geotermico del agua subterranea en acuiferos someros urbanos requiere un modelo numerico capaz de reproducir los efectos de la explotacion actual y ser capaz de predecir los impactos derivados de dicha actividad. En este trabajo se presenta el desarrollo preliminar de un modelo numerico que puede contribuir a mejorar la gestion de los recursos geotermicos someros en la ciudad de Zaragoza. El modelo numerico permite implementar toda la informacion hidrogeologica y termica recopilada, explicar esta informa- cion de forma coherente reproduciendo la fisica de fluidos y termodinamica en medios poroso s y predecir a medio y largo plazo los impactos producidos. Finalmente se muestran las posibilidades y ventajas derivadas del uso del modelo numerico en la gestion de permisos de concesion de derechos de explotacion para nuevos aprovechamientos. EnglishThe management of the thermal use of groundwater in shallow urban aquifers requires a numerical model capable...

It presents a systematic methodology to evaluate; the reservoir characteristics of Chipilapa-; Ahuachapan geothermal field through the highly; diluted natural manifestations (springs and domestic; wells) in its surroundings. The manifestations; are classified in three main groups according; to their mechanism of formation: high; salinity water (HSW), medium salinity water (MSW),; and Sulfated Water (SW). The reservoir temperature; at Chipilapa geothermal field is around; 220°C which is estimated with application of; various chemical geothermometers. The isotopic; studies indicate that the heating of local meteoric; water with the separated steam of deep; reservoir fluids is a dominating process in the; formation of springs and domestic wells fluids.; The process of formation of primary and secondary; vapor explains the isotopic composition; of fumaroles.

In order to investigate the mineralisation process, we conducted geochemical and isotopic analyses (major ions, 18 O, 2 H) of the thermal waters of springs and boreholes of Nigrita. This study shows that the thermal waters are o f meteoric origin. Appropriate geothermometers were applied on selected samp les of thermal waters for the determination of the deep aquifer temperature.

One of the main objectives of the West Darajat Edgefield Evaluation was to gain a better understanding of the southwest, west and northwest portions of the Darajat reservoir by using information from newly drilled wells and combining them with recent reservoir interpretations. Three step-out and edgefield wells in southwest and west Darajat were drilled during 2009-2011, and these wells offered new information about these portions of the reservoir. The long-term objective of this study is to assist in the strategic field development, specifically, whether to build a new pad in the northwest from which to drill additional production wells. Recent analyses indicate that the upflow of the Darajat geothermal system is located in the northwest based on consistent high CH4 (since initial production), heavier stable isotopes, high initial steam deliverabilities, low production decline rates and high initial reservoir pressures and temperatures. The results of the edgefield wells in the wes...

Urban Heat Island is part of an increase in air temperature, but UHI can also be said to be part of the relative heat of the surface or material above it. UHI has an impact on human health and comfort, air pollution, energy balance, and urban planning. However, over time, UHI can be predicted as a UHI mitigation effort in urban areas by using Landsat 8 imagery. The type of this study is qualitative descriptive research with multiple linear regression analysis. Based on the results of Landsat 8 image processing, the temperature distribution in the CBD area ranges from 22.6 – 33.6 oC. While the results of multiple linear regression analysis obtained four variables that have a strong influence on the increase in UHI on the surface in the CBD area, namely Transportation Emissions (X5) with mitigation efforts in the form of encouraging bike and ride activities, encouraging car-free days activities, and building fast public mass transportation. The Residential Land Area (X6) with mitigati...

Geothermal energy is a renewable alternative energy source. One of the analyses used to determine the characteristics of a geothermal field is water geochemical analysis. The target of this research is the Blawan-Ijen geothermal prospect area, Bondowoso. The geochemical analysis was carried out using AAS, Spectrophotometer and acid-base titration. This survey shows the characteristics of the geothermal system and geothermal fluid in the Blawan area, Ijen. From the chemical analysis of hot water, we found that the types of geothermal water fluids in the Blawan Ijen area vary. In samples BL1, BL2 and BL5 included in the type of Sulphate Water with the dominant elemental Sulphate (SO4) content is also known as Sulfuric Acid Water (Acid-Sulphate Water). Then for the BL4 sample included in the type of chloride water. This type of water is a type of geothermal fluid found in most areas with high-temperature systems. Areas with large-scale hot springs flowing with high Cl concentrations or...

El campo geotermico de Berlin, El Salvador, empezo a ex plotarse para generar electricidad en febrero de 1992. Desde entonces, el total de las aguas residuales producidas, que es de aproxim a da m e nte 350 kg/s, e s inyectado al reservorio del m i sm o cam po. La inyeccion es la unica opcion f actib le para este campo, pero la incrus tacion de silice en el reservo r io ha prov ocado la dis m inucion de la capacid a d de aceptacion de los pozos inyectores. La temperatura prom edio del a gua que se inyecta en caliente es actualm ente de 175° C con un pH pro m edio de 6.5. Con las nuevas condiciones im puestas por el proceso de generacion a ciclo binario, las aguas residuales se inyectaran a una tem p eratura de 140° C con un pH de 5.75, con lo que se evitara la precipitacion de silice dentro del si stem a de ciclo binario, del sistem a de acarreo y en los pozos inyectores. La tem p eratura del reservorio a la cual se inyecta el agua, esta en tre los 200 y 280o C. Se realizo la sim u ...

The design of ground source heat pumps is a fundamental step to ensure the high energy efficiency of heat pump systems throughout their operating years. To enhance the diffusion of ground source heat pump systems, two different tools are developed in the H2020 research project named, “Cheap GSHPs”: A design tool and a decision support system. In both cases, the energy demand of the buildings may not be calculated by the user. The main input data, to evaluate the size of the borehole heat exchangers, is the building energy demand. This paper presents a methodology to correlate energy demand, building typologies, and climatic conditions for different types of residential buildings. Rather than envelope properties, three insulation levels have been considered in different climatic conditions to set up a database of energy profiles. Analyzing European climatic test reference years, 23 locations have been considered. For each location, the overall energy and the mean hourly monthly energ...

In the context of the Geothermal Technology Program at GFZ, the former gas exploration well Gros Schonebeck 3/90 (50 km northeast of Berlin) was reopened and deepened to 4309 m depth. For the last 6 years, this well has served as a geothermal in-situ laboratory for in situ experiments and the development of stimulation concepts. The objective of these stimulation operations was to create secondary flow paths and to improve the inflow performance of the well. The well makes the deep sedimentary Rotliegend reservoir accessible, which is characterized by water bearing porous and fractured rocks. To complet e a potential doublet for power generation, the second well Gros Schonebeck 4/05 was drilled in late 2006. At pay -zone depth level the maximum distance between the two wells is approximately 500m. The most promising sandstone layers for stimulation were identified by measured porosity distribution, water saturation and calculated permeability data. This information is a prerequisite...