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Sustainable energy development in the farming sector is an essential strategy to respond the combined challenge of achieving a reliable and affordable solution but including mitigation and adaptation to climate change. Intensive breeding farms require maintaining an adequate indoor thermal environment that results in high energy demands, usually covered by fossil fuels and electricity. This paper addresses the application of the combined slurry technology for a particular pig farm that currently uses a diesel boiler to supply the piglet heating energy needs. The study also considers different options based on closed ground source heat pump systems. After the design of the slurry alternative and the geothermal ones, notable advantages are detected compared to the existing diesel system. Results show that the implementation of the slurry technology implies an important reduction of the operational costs, which, in turn, involves short amortization periods for this system in relation to the diesel one. Greenhouse gases emissions are also highly reduced in the slurry alternative based on the low electricity use of the heat pump. The environmental side is reinforced by the reduction of polluting substances such as methane of ammonia derived from the descent of temperature of the slurry.
Cristina Sáez Blázquez; David Borge-Diez; Ignacio Martín Nieto; Miguel Ángel Maté-González; Arturo Farfán Martín; Diego González-Aguilera. Investigating the potential of the slurry technology for sustainable pig farm heating. Energy 2021, 234, 121258 .
AMA StyleCristina Sáez Blázquez, David Borge-Diez, Ignacio Martín Nieto, Miguel Ángel Maté-González, Arturo Farfán Martín, Diego González-Aguilera. Investigating the potential of the slurry technology for sustainable pig farm heating. Energy. 2021; 234 ():121258.
Chicago/Turabian StyleCristina Sáez Blázquez; David Borge-Diez; Ignacio Martín Nieto; Miguel Ángel Maté-González; Arturo Farfán Martín; Diego González-Aguilera. 2021. "Investigating the potential of the slurry technology for sustainable pig farm heating." Energy 234, no. : 121258.
This research focuses on the study of the ruins of a large building known as “El Torreón” (the Tower), belonging to the Ulaca oppidum (Solosancho, Province of Ávila, Spain). Different remote sensing and geophysical approaches have been used to fulfil this objective, providing a better understanding of the building’s functionality in this town, which belongs to the Late Iron Age (ca. 300–50 BCE). In this sense, the outer limits of the ruins have been identified using photogrammetry and convergent drone flights. An additional drone flight was conducted in the surrounding area to find additional data that could be used for more global interpretations. Magnetometry was used to analyze the underground bedrock structure and ground penetrating radar (GPR) was employed to evaluate the internal layout of the ruins. The combination of these digital methodologies (surface and underground) has provided a new perspective for the improved interpretation of “El Torreón” and its characteristics. Research of this type presents additional guidelines for better understanding of the role of this structure with regards to other buildings in the Ulaca oppidum. The results of these studies will additionally allow archaeologists to better plan future interventions while presenting new data that can be used for the interpretation of this archaeological complex on a larger scale.
Miguel Maté-González; Cristina Sáez Blázquez; Pedro Carrasco García; Jesús Rodríguez-Hernández; Jesús Fernández Hernández; Javier Vallés Iriso; Yolanda Torres; Libertad Troitiño Torralba; Lloyd Courtenay; Diego González-Aguilera; Serafín López-Cuervo; Julián Aguirre de Mata; Jesús Velasco Gómez; Marco Piras; Andrea Filippo; José Yravedra; Maximiliano Fernández Fernández; Teresa Chapa; Gonzalo Ruiz Zapatero; Jesús Álvarez-Sanchís. Towards a Combined Use of Geophysics and Remote Sensing Techniques for the Characterization of a Singular Building: “El Torreón” (the Tower) at Ulaca Oppidum (Solosancho, Ávila, Spain). Sensors 2021, 21, 2934 .
AMA StyleMiguel Maté-González, Cristina Sáez Blázquez, Pedro Carrasco García, Jesús Rodríguez-Hernández, Jesús Fernández Hernández, Javier Vallés Iriso, Yolanda Torres, Libertad Troitiño Torralba, Lloyd Courtenay, Diego González-Aguilera, Serafín López-Cuervo, Julián Aguirre de Mata, Jesús Velasco Gómez, Marco Piras, Andrea Filippo, José Yravedra, Maximiliano Fernández Fernández, Teresa Chapa, Gonzalo Ruiz Zapatero, Jesús Álvarez-Sanchís. Towards a Combined Use of Geophysics and Remote Sensing Techniques for the Characterization of a Singular Building: “El Torreón” (the Tower) at Ulaca Oppidum (Solosancho, Ávila, Spain). Sensors. 2021; 21 (9):2934.
Chicago/Turabian StyleMiguel Maté-González; Cristina Sáez Blázquez; Pedro Carrasco García; Jesús Rodríguez-Hernández; Jesús Fernández Hernández; Javier Vallés Iriso; Yolanda Torres; Libertad Troitiño Torralba; Lloyd Courtenay; Diego González-Aguilera; Serafín López-Cuervo; Julián Aguirre de Mata; Jesús Velasco Gómez; Marco Piras; Andrea Filippo; José Yravedra; Maximiliano Fernández Fernández; Teresa Chapa; Gonzalo Ruiz Zapatero; Jesús Álvarez-Sanchís. 2021. "Towards a Combined Use of Geophysics and Remote Sensing Techniques for the Characterization of a Singular Building: “El Torreón” (the Tower) at Ulaca Oppidum (Solosancho, Ávila, Spain)." Sensors 21, no. 9: 2934.
Low enthalpy geothermal resources play an essential role in climate change mitigation. When ensuring the correct future operation of ground-source heat pump systems, an accurate design is mandatory. In this sense, different methodologies can be implemented. Although using sophisticated software constitutes the most optimal solution, its implementation is sometimes inviable in certain projects (the increase of the initial investment required is not justified in small plants). This work is focused on evaluating and comparing procedures used in the design of shallow geothermal systems. Thus, the research includes a simple method based on manual calculations, the Climasoft free application, Earth Energy Designer (EED) software, and the new geothermal tool GES-CAL developed by researchers from the TIDOP Research Group (University of Salamanca). The objective is to evaluate this new software and compare the results of all the detailed methodologies. This comparison derives from applying these tools in the calculation of the same case study (a single-family house placed in Ávila, Spain). Results show that the easiest methods involve oversized well-field schemas that also mean higher initial investments. Regarding GES-CAL, it is considered an accurate and valid alternative for the design of all heat exchanger configurations, especially for those installations placed in the region of Ávila. However, EED is recommended to calculate high-power geothermal systems that require an exhaustive analysis of the ground and the heat carrier fluid behaviour.
Cristina Sáez-Blázquez; Ignacio Martín-Nieto; Arturo Farfán-Martín; Diego González-Aguilera. Evaluation of different methodologies for the design of the wellfield in shallow geothermal systems. Revista Facultad de Ingeniería Universidad de Antioquia 2021, 1 .
AMA StyleCristina Sáez-Blázquez, Ignacio Martín-Nieto, Arturo Farfán-Martín, Diego González-Aguilera. Evaluation of different methodologies for the design of the wellfield in shallow geothermal systems. Revista Facultad de Ingeniería Universidad de Antioquia. 2021; ():1.
Chicago/Turabian StyleCristina Sáez-Blázquez; Ignacio Martín-Nieto; Arturo Farfán-Martín; Diego González-Aguilera. 2021. "Evaluation of different methodologies for the design of the wellfield in shallow geothermal systems." Revista Facultad de Ingeniería Universidad de Antioquia , no. : 1.
Thermal characterization of soils is essential for many applications, including design of geothermal systems. Traditional devices focus on the computation of thermal conductivity, omitting the analysis of the convection effect, which is important for horizontal geothermal systems. In this paper, a procedure based on the monitoring of the surface of the soil with a thermal infrared (TIR) camera is developed for the evaluation of the global thermal imbalance on the surface and in-depth. This procedure allows for the computation of thermal conductivity and global convection heat rate, consequently constituting a complete thermal characterization of the geothermal system. The validation of the results is performed through the evaluation of the radiometric calibration of the thermal infrared camera used for the monitoring and the comparison of the thermal conductivity values obtained in-depth, with traditional methods, and for the surface of the system.
Susana Del Pozo; Cristina Sáez Blázquez; Ignacio Martín Nieto; Susana Lagüela. Integrated Approach for Detecting Convection Effects in Geothermal Environments Based on TIR Camera Measurements. Applied Sciences 2021, 11, 3185 .
AMA StyleSusana Del Pozo, Cristina Sáez Blázquez, Ignacio Martín Nieto, Susana Lagüela. Integrated Approach for Detecting Convection Effects in Geothermal Environments Based on TIR Camera Measurements. Applied Sciences. 2021; 11 (7):3185.
Chicago/Turabian StyleSusana Del Pozo; Cristina Sáez Blázquez; Ignacio Martín Nieto; Susana Lagüela. 2021. "Integrated Approach for Detecting Convection Effects in Geothermal Environments Based on TIR Camera Measurements." Applied Sciences 11, no. 7: 3185.
Usually thermal response tests are restricted to big geothermal projects; the high investment makes them less suitable for designing domestic low-enthalpy geothermal energy systems. The work here presented aims to study the influence of time reduction in thermal response tests on their precision. Due to the importance of the correct assessment of the thermal characterization of the ground for any kind of geothermal system, time reduction in this essay could make it more affordable to be implemented in some domestic systems. A thermal response test has been implemented, and several time intervals of the test have been considered in order to obtain different results for the thermal conductivity of the ground. The mentioned results have been then compared and also the domestic geothermal systems designed from them by the use of the geothermal software GES-CAL. Results have shown that, in some cases (our testing borehole has some singular characteristics), a significant time reduction in the data acquisition process of the thermal response test does not compromise seriously the precision of the results.
Ignacio Nieto; Cristina Blázquez; Arturo Martín; Diego González-Aguilera. Analysis of the Influence of Reducing the Duration of a Thermal Response Test in a Water-Filled Geothermal Borehole Located in Spain. Energies 2020, 13, 6693 .
AMA StyleIgnacio Nieto, Cristina Blázquez, Arturo Martín, Diego González-Aguilera. Analysis of the Influence of Reducing the Duration of a Thermal Response Test in a Water-Filled Geothermal Borehole Located in Spain. Energies. 2020; 13 (24):6693.
Chicago/Turabian StyleIgnacio Nieto; Cristina Blázquez; Arturo Martín; Diego González-Aguilera. 2020. "Analysis of the Influence of Reducing the Duration of a Thermal Response Test in a Water-Filled Geothermal Borehole Located in Spain." Energies 13, no. 24: 6693.
The use of low-impact energy sources is gradually growing with the aim of reducing greenhouse gases emission and air pollution. The alternatives offered by geothermal systems are one of the key solutions for a future renewable development, enabling the electrification of heating systems and the use of biofuels. This research addresses an overview of geothermal heating systems using ground source heat pumps in different European countries. Besides the traditional electrical heat pumps, gas engine heat pumps aided by natural gas or biogas are analysed in three areas. From a previous research, the technical parameters defining the geothermal system are used here to evaluate the most appropriate system in each scenario. The evaluation of different influential factors (operational costs, initial investment, environmental impact, and availability) allows defining the most recommendable systems for each area. Results of this multi-parametric study show that gas engine heat pumps aided by biogas could mean an excellent solution in all countries, also contributing to the management of waste and polluting substances. If biogas systems were not available, the electrical heat pump would be the first option for areas 1 and 3 (Italy and Sweden) but not for area 2 (United Kingdom), where natural gas is preferred.
Cristina Sáez Blázquez; David Borge-Diez; Ignacio Martín Nieto; Arturo Farfán Martín; Diego González-Aguilera. Multi-parametric evaluation of electrical, biogas and natural gas geothermal source heat pumps. Renewable Energy 2020, 163, 1682 -1691.
AMA StyleCristina Sáez Blázquez, David Borge-Diez, Ignacio Martín Nieto, Arturo Farfán Martín, Diego González-Aguilera. Multi-parametric evaluation of electrical, biogas and natural gas geothermal source heat pumps. Renewable Energy. 2020; 163 ():1682-1691.
Chicago/Turabian StyleCristina Sáez Blázquez; David Borge-Diez; Ignacio Martín Nieto; Arturo Farfán Martín; Diego González-Aguilera. 2020. "Multi-parametric evaluation of electrical, biogas and natural gas geothermal source heat pumps." Renewable Energy 163, no. : 1682-1691.
The geothermal resources in Spain have been a source of deep research in recent years and are, in general, well-defined. However, there are some areas where the records from the National Institute for Geology and Mining show thermal activity from different sources despite no geothermal resources being registered there. This is the case of the area in the south of the Duero basin where this research was carried out. Seizing the opportunity of a deep borehole being drilled in the location, some geophysical resources were used to gather information about the geothermal properties of the area. The employed geophysical methods were time-domain electromagnetics (TDEM) and borehole logging; the first provided information about the depth of the bedrock and the general geological structure, whereas the second one gave more detail on the geological composition of the different layers and a temperature record across the whole sounding. The results allowed us to establish the geothermal gradient of the area and to discern the depth of the bedrock. Using the first 200 m of the borehole logging, the thermal conductivity of the ground for shallow geothermal systems was estimated.
Ignacio Nieto; Pedro Carrasco García; Cristina Sáez Blázquez; Arturo Farfán Martín; Diego González-Aguilera; Javier Carrasco García. Geophysical Prospecting for Geothermal Resources in the South of the Duero Basin (Spain). Energies 2020, 13, 5397 .
AMA StyleIgnacio Nieto, Pedro Carrasco García, Cristina Sáez Blázquez, Arturo Farfán Martín, Diego González-Aguilera, Javier Carrasco García. Geophysical Prospecting for Geothermal Resources in the South of the Duero Basin (Spain). Energies. 2020; 13 (20):5397.
Chicago/Turabian StyleIgnacio Nieto; Pedro Carrasco García; Cristina Sáez Blázquez; Arturo Farfán Martín; Diego González-Aguilera; Javier Carrasco García. 2020. "Geophysical Prospecting for Geothermal Resources in the South of the Duero Basin (Spain)." Energies 13, no. 20: 5397.
Geothermal energy is becoming essential to deal with the catastrophic effect of climate change. Although the totality of the Earth’s crust allows the exploitation of shallow geothermal resources, it is important to identify those areas with higher thermal possibilities. In this sense, geophysical prospecting plays a vital role in the recognition and estimation of potential geothermal resources. This research evaluates the geothermal conditions of a certain area located in the center of Spain. The evaluation is mainly based on geological and geophysical studies and, in particular, the Time Domain Electromagnetic Method and the Electrical Resistivity Tomography. Once we analyzed the geology and the historical thermal evidence near the study area, our geophysical results were used to define the geothermal possibilities from a double perspective. In relation to anomalous heat gradient, the identification of a fault and the contact with impermeable granitic materials at the depth of 180 m denotes a potential location for the extraction of groundwater. Regarding the common ground-source heat-pump uses, the analysis has allowed the determination of the most appropriate area for the location of the geothermal well field. Finally, the importance of accurately defining the position of the drillings was confirmed by using software GES-CAL.
Cristina Sáez Blázquez; Pedro Carrasco García; Ignacio Martín Nieto; Miguel Ángel Maté-González; Arturo Farfán Martín; Diego González-Aguilera. Characterizing Geological Heterogeneities for Geothermal Purposes through Combined Geophysical Prospecting Methods. Remote Sensing 2020, 12, 1 .
AMA StyleCristina Sáez Blázquez, Pedro Carrasco García, Ignacio Martín Nieto, Miguel Ángel Maté-González, Arturo Farfán Martín, Diego González-Aguilera. Characterizing Geological Heterogeneities for Geothermal Purposes through Combined Geophysical Prospecting Methods. Remote Sensing. 2020; 12 (12):1.
Chicago/Turabian StyleCristina Sáez Blázquez; Pedro Carrasco García; Ignacio Martín Nieto; Miguel Ángel Maté-González; Arturo Farfán Martín; Diego González-Aguilera. 2020. "Characterizing Geological Heterogeneities for Geothermal Purposes through Combined Geophysical Prospecting Methods." Remote Sensing 12, no. 12: 1.
The purpose of this paper is to present a new tool developed for the calculation and design of shallow closed-loop geothermal systems. Most of the available geothermal computer programs only allow to consider vertical heat exchangers configurations (i.e. single or double-U tubes), being the horizontal and helical designs excluded. As an attempt to fill this gap, GES–CAL tool, presented here, is capable of providing the complete design of all the most common configurations used in low enthalpy geothermal systems. This software was initially developed for its implementation in the region of Ávila (Spain), including the most relevant results of previous author’s researches in this area. Throughout this work, the new software is deeply described and implemented in the calculation of three different study cases. Results of GES–CAL are complementary compared with the ones obtained from the most used geothermal software, EED (Earth Energy Designer). From the analysis of these results, it was possible to conclude that GES–CAL tool constitutes an optimal solution for planning a shallow geothermal system, but especially for those installations placed in the region of Ávila. In this area, the well field can be designed in more precise way which results in lower drilling lengths and, hence, lower initial investments. The conclusions of this work indicate that GES–CAL offers remarkable advantages such as the automatic calculation of the space energy demand, the inclusion of all the heat exchanger configurations and an economic and environmental evaluation of the final geothermal solution.
Cristina Sáez Bláquez; Ignacio Martín Nieto; Rocío Mora; Arturo Farfán Martín; Diego González-Aguilera. GES-CAL: A new computer program for the design of closed-loop geothermal energy systems. Geothermics 2020, 87, 101852 .
AMA StyleCristina Sáez Bláquez, Ignacio Martín Nieto, Rocío Mora, Arturo Farfán Martín, Diego González-Aguilera. GES-CAL: A new computer program for the design of closed-loop geothermal energy systems. Geothermics. 2020; 87 ():101852.
Chicago/Turabian StyleCristina Sáez Bláquez; Ignacio Martín Nieto; Rocío Mora; Arturo Farfán Martín; Diego González-Aguilera. 2020. "GES-CAL: A new computer program for the design of closed-loop geothermal energy systems." Geothermics 87, no. : 101852.
This research work aims at a multinational study in Europe of the emissions and energy costs generated by the operation of low enthalpy geothermal systems, with heat pumps fed by different energy sources. From an economic point of view, natural gas and biogas prices are, usually, lower than electricity ones. So it may be advantageous to use these energy sources to feed the heat pumps instead of electricity. From the environmental point of view, it is intended to highlight the fact that under certain conditions of electricity production (electricity mix), more CO2 emissions are produced by electricity consumption than using other a priori less “clean” energy sources such as natural gas. To establish the countries where each of the different heat pumps may be more cost-efficient and environmentally friendly, data from multi-source geospatial databases have been collected and analyzed. The results show that in the majority of cases, the electric heat pump is the most recommendable solution. However, there are some geographic locations (such as Poland and Estonia), where the gas engine heat pump may be a better alternative.
Ignacio Martín Nieto; David Borge-Diez; Cristina Sáez Blázquez; Arturo Farfán Martín; Diego González-Aguilera. Study on Geospatial Distribution of the Efficiency and Sustainability of Different Energy-Driven Heat Pumps Included in Low Enthalpy Geothermal Systems in Europe. Remote Sensing 2020, 12, 1093 .
AMA StyleIgnacio Martín Nieto, David Borge-Diez, Cristina Sáez Blázquez, Arturo Farfán Martín, Diego González-Aguilera. Study on Geospatial Distribution of the Efficiency and Sustainability of Different Energy-Driven Heat Pumps Included in Low Enthalpy Geothermal Systems in Europe. Remote Sensing. 2020; 12 (7):1093.
Chicago/Turabian StyleIgnacio Martín Nieto; David Borge-Diez; Cristina Sáez Blázquez; Arturo Farfán Martín; Diego González-Aguilera. 2020. "Study on Geospatial Distribution of the Efficiency and Sustainability of Different Energy-Driven Heat Pumps Included in Low Enthalpy Geothermal Systems in Europe." Remote Sensing 12, no. 7: 1093.
Ground source heat pump (GSHP) systems are becoming popular in space heating and cooling applications. Despite this fact, in most countries, the role of this energy is not as important as it should be nowadays according to its capabilities for energy generation without CO2 emissions, mainly due to the lack of technical knowledge about GSHP performance. The analysis of the physical processes that take part in the geothermal exchanges is necessary to allow the optimal exploitation of the geothermal resources. For all the above, an experimental geothermal device was built in the laboratory to control the phenomena that take place in a borehole heat exchanger (BHE). A 1-m high single-U heat exchanger was inserted in the center of a polyethylene container which also included granular material (surrounding ground) and the grouting material. Temperature sensors were situated in different positions of the experimental setup. Physical processes are evaluated to finally validate the model. Numerous applications can be developed from the experimental BHE. In this research, the determination of the thermal conductivity of the material used as medium was carried out. Results of this parameter were also compared with the ones obtained from the use of the KD2 Pro device.
Cristina Sáez Blázquez; Laura Piedelobo; Jesús Fernández-Hernández; Ignacio Martín Nieto; Arturo Farfán Martín; Susana Lagüela; Diego González-Aguilera. Novel Experimental Device to Monitor the Ground Thermal Exchange in a Borehole Heat Exchanger. Energies 2020, 13, 1270 .
AMA StyleCristina Sáez Blázquez, Laura Piedelobo, Jesús Fernández-Hernández, Ignacio Martín Nieto, Arturo Farfán Martín, Susana Lagüela, Diego González-Aguilera. Novel Experimental Device to Monitor the Ground Thermal Exchange in a Borehole Heat Exchanger. Energies. 2020; 13 (5):1270.
Chicago/Turabian StyleCristina Sáez Blázquez; Laura Piedelobo; Jesús Fernández-Hernández; Ignacio Martín Nieto; Arturo Farfán Martín; Susana Lagüela; Diego González-Aguilera. 2020. "Novel Experimental Device to Monitor the Ground Thermal Exchange in a Borehole Heat Exchanger." Energies 13, no. 5: 1270.
District heating systems are gaining an increasing importance in the space heating and the production of Domestic Hot Water. Focusing on the geothermal energy as the energy supply of these systems, an optimal design could involve an increased number of geothermal district heating installations. This research presents two different designs of a groundwater heat pump system from the application of initial real data. Both designs differ in the heat pumps: 1 installation in scenario 1 and 3 installations in scenario 2. The procedure includes the calculation of all the required geothermal parameters in both assumptions. Optimization of the drilling schema is carried out using COMSOL Multiphysics software. Technical and economic results reveal that scenario 1 is the most suitable option for the study case here presented. Global initial investment is lower in scenario 1 the same as the annual operational costs since the coefficient of performance of the heat pumps in this scenario 1 is slightly higher than the one of each module of scenario 2.
Cristina Sáez Blázquez; Vittorio Verda; Ignacio Martín Nieto; Arturo Farfán Martín; Diego González-Aguilera. Analysis and optimization of the design parameters of a district groundwater heat pump system in Turin, Italy. Renewable Energy 2019, 149, 374 -383.
AMA StyleCristina Sáez Blázquez, Vittorio Verda, Ignacio Martín Nieto, Arturo Farfán Martín, Diego González-Aguilera. Analysis and optimization of the design parameters of a district groundwater heat pump system in Turin, Italy. Renewable Energy. 2019; 149 ():374-383.
Chicago/Turabian StyleCristina Sáez Blázquez; Vittorio Verda; Ignacio Martín Nieto; Arturo Farfán Martín; Diego González-Aguilera. 2019. "Analysis and optimization of the design parameters of a district groundwater heat pump system in Turin, Italy." Renewable Energy 149, no. : 374-383.
This paper is focused on the Middle Paleolithic rock shelter called “Abrigo de San Lázaro”, placed in the Eresma River valley (Segovia, Spain). In this area, a multisource geomatic approach is used. On the one hand, the external envelope of the shelter has been digitalized by the means of an efficient combination between aerial photogrammetry and laser scanning (static and mobile). On the other hand, the ground penetrating radar and the electric tomography were used with the aim of evaluating the inner disposition of the shelter. The combination of both digitalization (external and internal) has allowed for improving the knowledge of the site characteristics that, in turn, will facilitate the future excavation works. The results of these studies allow archaeologists to know new data for a better understanding of the site formation (geology of the site, sedimentary potential, rock shelter dimensions, etc.) and the events that took place in it (knowing its historical evolution, especially the interaction between man and the environment). Additionally, the information obtained from these studies is very useful to plan future excavation works on the site.
Miguel Ángel Maté-González; Luis Javier Sánchez-Aparicio; Cristina Sáez Blázquez; Pedro Carrasco García; David Álvarez-Alonso; María De Andrés Herrero; Juan Carlos García-Davalillo; Diego González-Aguilera; Mario Hernández Ruiz; Luis Jordá Bordehore; Carlos López Carnicero; Rocío Mora. On the Combination of Remote Sensing and Geophysical Methods for the Digitalization of the San Lázaro Middle Paleolithic Rock Shelter (Segovia, Central Iberia, Spain). Remote Sensing 2019, 11, 2035 .
AMA StyleMiguel Ángel Maté-González, Luis Javier Sánchez-Aparicio, Cristina Sáez Blázquez, Pedro Carrasco García, David Álvarez-Alonso, María De Andrés Herrero, Juan Carlos García-Davalillo, Diego González-Aguilera, Mario Hernández Ruiz, Luis Jordá Bordehore, Carlos López Carnicero, Rocío Mora. On the Combination of Remote Sensing and Geophysical Methods for the Digitalization of the San Lázaro Middle Paleolithic Rock Shelter (Segovia, Central Iberia, Spain). Remote Sensing. 2019; 11 (17):2035.
Chicago/Turabian StyleMiguel Ángel Maté-González; Luis Javier Sánchez-Aparicio; Cristina Sáez Blázquez; Pedro Carrasco García; David Álvarez-Alonso; María De Andrés Herrero; Juan Carlos García-Davalillo; Diego González-Aguilera; Mario Hernández Ruiz; Luis Jordá Bordehore; Carlos López Carnicero; Rocío Mora. 2019. "On the Combination of Remote Sensing and Geophysical Methods for the Digitalization of the San Lázaro Middle Paleolithic Rock Shelter (Segovia, Central Iberia, Spain)." Remote Sensing 11, no. 17: 2035.
Very low enthalpy geothermal systems have been traditionally associated to the use of electricity as primary energy heat pumps supply. Gas engine heat pumps (GEHP) have been recently introduced in the current market. In this research, the electric heat pumps (EHP) as well as the GEHPs (considering natural gas and biogas as combustibles) have been analysed. The calculation of the ground source heat pump (GSHP) system has been made for a building placed in three different areas. Results reveal the influence of the heat pump configuration on the whole geothermal design. This research finally considers the European policies whose aim is a sustainable low-carbon economy by 2020. According to the existing Energy Efficiency Directive, energy requirements are defined for new and existing residential and non-residential buildings in the Member States. Based on these standards, the research compares the geothermal heat pump scenarios and a traditional one to determine if they would meet the regulation. Final results show that the Directive is a highly-demanding regulation that can only be respected by using EHP in one of the areas. The rest of geothermal heat pumps scenarios are much closer to meeting the energy standards than the traditional fossil heating sources.
Cristina Sáez Blázquez; David Borge-Diez; Ignacio Martín Nieto; Arturo Farfán Martín; Diego González-Aguilera. Technical optimization of the energy supply in geothermal heat pumps. Geothermics 2019, 81, 133 -142.
AMA StyleCristina Sáez Blázquez, David Borge-Diez, Ignacio Martín Nieto, Arturo Farfán Martín, Diego González-Aguilera. Technical optimization of the energy supply in geothermal heat pumps. Geothermics. 2019; 81 ():133-142.
Chicago/Turabian StyleCristina Sáez Blázquez; David Borge-Diez; Ignacio Martín Nieto; Arturo Farfán Martín; Diego González-Aguilera. 2019. "Technical optimization of the energy supply in geothermal heat pumps." Geothermics 81, no. : 133-142.
In ground source heat pump systems, the thermal properties of the ground, where the well field is planned to be located, are essential for proper geothermal design. In this regard, estimation of ground thermal conductivity has been carried out by the implementation of different techniques and laboratory tests. In this study, several methods to obtain the thermal properties of the ground are applied in order to compare them with the reference thermal response test (TRT). These methods (included in previous research works) are carried out in the same geological environment and on the same borehole, in order to make an accurate comparison. All of them provide a certain value for the thermal conductivity of the borehole. These results are compared to the one obtained from the TRT carried out in the same borehole. The conclusions of this research allow the validation of alternative solutions based on the use of a thermal conductive equipment and the application of geophysics techniques. Seismic prospecting has been proven as a highly recommendable indicator of the thermal conductivity of a borehole column, obtaining rate errors of below 1.5%.
Cristina Sáez Blázquez; Ignacio Martín Nieto; Arturo Farfán Martín; Diego González-Aguilera; Pedro Carrasco García. Comparative Analysis of Different Methodologies Used to Estimate the Ground Thermal Conductivity in Low Enthalpy Geothermal Systems. Energies 2019, 12, 1672 .
AMA StyleCristina Sáez Blázquez, Ignacio Martín Nieto, Arturo Farfán Martín, Diego González-Aguilera, Pedro Carrasco García. Comparative Analysis of Different Methodologies Used to Estimate the Ground Thermal Conductivity in Low Enthalpy Geothermal Systems. Energies. 2019; 12 (9):1672.
Chicago/Turabian StyleCristina Sáez Blázquez; Ignacio Martín Nieto; Arturo Farfán Martín; Diego González-Aguilera; Pedro Carrasco García. 2019. "Comparative Analysis of Different Methodologies Used to Estimate the Ground Thermal Conductivity in Low Enthalpy Geothermal Systems." Energies 12, no. 9: 1672.
The implementation of the very low geothermal energy is not as extended as the rest of renewable energies. The high initial investment these systems usually require makes them unaffordable for most users. In this regard, this research tries to emphasize the importance of a suitable dimensioning of the whole geothermal plant. With that aim, three different calculation methods have been presented. One of them is based on manual calculations using standard values while the two remaining assumptions consider the use of specific geothermal software. Results reveal that the most suitable method is constituted by the implementation of optimized parameters in the geothermal software. These parameters are obtained from a series of previous analysis and laboratory tests. Applying the most appropriated procedure the initial investment is considerably reduced. Additionally, the electricity consumption of the heat pump is also lower using the mentioned calculation. In this way, the present research demonstrates that and adjusted and proper calculation process can make the geothermal system more attractive for a large number of users.
Cristina Sáez Blázquez; Ignacio Martín Nieto; Arturo Farfán Martín; Diego González-Aguilera. Optimization of the Dimensioning Process of a Very Low Enthalpy Geothermal Installation. Communications in Computer and Information Science 2019, 179 -191.
AMA StyleCristina Sáez Blázquez, Ignacio Martín Nieto, Arturo Farfán Martín, Diego González-Aguilera. Optimization of the Dimensioning Process of a Very Low Enthalpy Geothermal Installation. Communications in Computer and Information Science. 2019; ():179-191.
Chicago/Turabian StyleCristina Sáez Blázquez; Ignacio Martín Nieto; Arturo Farfán Martín; Diego González-Aguilera. 2019. "Optimization of the Dimensioning Process of a Very Low Enthalpy Geothermal Installation." Communications in Computer and Information Science , no. : 179-191.
In designing low enthalpy geothermal systems, the ideal location and length of the boreholes in the well-field is the key to improve the performance and reduce the costs of the installation. The correct assessment of the heat conductivity of the ground (λ) plays also a very important role in estimating the amount of energy that we are going to be able to obtain from the subsoil and the ideal pace of the process. In low enthalpy geothermal installations based on granite type environments is especially important to improve the information we have from the subsoil at a small scale. This is due to the great horizontal variation we can find on this kind of terrain. Electrical conductivity (C = 1/ρ, ρ = resistivity in ohm meters) can be related to thermal conductivity (λ) of many rock types (Directive (EU), 2019) (see Robertson, 1988). We show that a 3D electrical resistivity survey can be used as a proxy for λ in terrain with weathered and solid granitic rock. Knowledge of λ is essential for the design of efficient ground source heat pump systems that use vertical wells for closed-loop systems. Shorter well lengths are accomplished if wells are in solid granite with high λ. Furthermore the electrical resistivity survey identifies low density, clayey subsurface materials that may require specialized drilling methods. Project cost savings can result from shorter borehole lengths, number of holes, and correct drilling methods.
Ignacio Martín Nieto; Arturo Farfán Martín; Cristina Sáez Blázquez; Diego González Aguilera; Pedro Carrasco García; Emilio Farfán Vasco; Javier Carrasco García. Use of 3D electrical resistivity tomography to improve the design of low enthalpy geothermal systems. Geothermics 2019, 79, 1 -13.
AMA StyleIgnacio Martín Nieto, Arturo Farfán Martín, Cristina Sáez Blázquez, Diego González Aguilera, Pedro Carrasco García, Emilio Farfán Vasco, Javier Carrasco García. Use of 3D electrical resistivity tomography to improve the design of low enthalpy geothermal systems. Geothermics. 2019; 79 ():1-13.
Chicago/Turabian StyleIgnacio Martín Nieto; Arturo Farfán Martín; Cristina Sáez Blázquez; Diego González Aguilera; Pedro Carrasco García; Emilio Farfán Vasco; Javier Carrasco García. 2019. "Use of 3D electrical resistivity tomography to improve the design of low enthalpy geothermal systems." Geothermics 79, no. : 1-13.
As a renewable energy source, geothermal energy can provide base-load power supply both for electricity and direct uses, such as space heating. Regarding this last use, in the present study, district heating systems aided by geothermal energy, the so-called geothermal district heating systems, are studied. Thus, three different options of a geothermal district heating system are evaluated and compared in terms of environmental and economic aspects with a traditional fossil installation. Calculations were carried out from a particular study case, a set of buildings located Province of León in the north of Spain. From real data of each of the assumptions considered, an exhaustive comparison among the different scenarios studied, was thoroughly made. Results revealed the most suitable option from an economic point of view but always considering the environmental impacts of each one. In this regard, the assumption of a district heating system totally supplied by geothermal energy clearly stands out from the rest of options. Thus, the manuscript main objective is to emphasise the advantages of these systems as they constitute the ideal solution from both the economic and environmental parameters analysed.
Cristina Sáez Blázquez; Arturo Farfán Martín; Ignacio Martín Nieto; Diego González-Aguilera. Economic and Environmental Analysis of Different District Heating Systems Aided by Geothermal Energy. Energies 2018, 11, 1265 .
AMA StyleCristina Sáez Blázquez, Arturo Farfán Martín, Ignacio Martín Nieto, Diego González-Aguilera. Economic and Environmental Analysis of Different District Heating Systems Aided by Geothermal Energy. Energies. 2018; 11 (5):1265.
Chicago/Turabian StyleCristina Sáez Blázquez; Arturo Farfán Martín; Ignacio Martín Nieto; Diego González-Aguilera. 2018. "Economic and Environmental Analysis of Different District Heating Systems Aided by Geothermal Energy." Energies 11, no. 5: 1265.
Cristina Sáez Blázquez; Arturo Farfán Martín; Pedro Carrasco García; Diego González-Aguilera. Thermal conductivity characterization of three geological formations by the implementation of geophysical methods. Geothermics 2018, 72, 101 -111.
AMA StyleCristina Sáez Blázquez, Arturo Farfán Martín, Pedro Carrasco García, Diego González-Aguilera. Thermal conductivity characterization of three geological formations by the implementation of geophysical methods. Geothermics. 2018; 72 ():101-111.
Chicago/Turabian StyleCristina Sáez Blázquez; Arturo Farfán Martín; Pedro Carrasco García; Diego González-Aguilera. 2018. "Thermal conductivity characterization of three geological formations by the implementation of geophysical methods." Geothermics 72, no. : 101-111.
The thermal conductivity of soils and rocks constitutes an important property for the design of geothermal energy foundations and borehole heat exchange systems. Therefore, it is interesting to find new alternatives to define this parameter involved in the calculation of very low enthalpy geothermal installations. This work presents the development of an experimental set-up for measurements of thermal conductivity of soils and rocks. The device was designed based on the principle of the Guarded Hot Plate method using as heat source a laboratory heater. The thermal conductivity of thirteen rocky and soil samples was experimentally measured. Results are finally compared with the most common thermal conductivity values for each material. In summary, the aim of the present research is suggesting a procedure to determine the thermal conductivity parameter by a simple and economic way. Thus, increases of the final price of these systems that techniques such as the “Thermal Response Test” (TRT) involvs, could be avoided. Calculations with software “Earth Energy Designer” (EED) highlighted the importance of knowing the thermal conductivity of the surrounding ground of these geothermal systems.
Cristina Sáez Blázquez; Arturo Farfán Martín; Ignacio Martín Nieto; Diego Gonzalez-Aguilera. Measuring of Thermal Conductivities of Soils and Rocks to Be Used in the Calculation of A Geothermal Installation. Energies 2017, 10, 795 .
AMA StyleCristina Sáez Blázquez, Arturo Farfán Martín, Ignacio Martín Nieto, Diego Gonzalez-Aguilera. Measuring of Thermal Conductivities of Soils and Rocks to Be Used in the Calculation of A Geothermal Installation. Energies. 2017; 10 (6):795.
Chicago/Turabian StyleCristina Sáez Blázquez; Arturo Farfán Martín; Ignacio Martín Nieto; Diego Gonzalez-Aguilera. 2017. "Measuring of Thermal Conductivities of Soils and Rocks to Be Used in the Calculation of A Geothermal Installation." Energies 10, no. 6: 795.