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Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG) emissions. Geothermal energy is the thermal energy stored in the underground, including any contained fluid, which is available for extraction and conversion into energy products. Electricity...
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... It reports that the equilibrium temperature at a depth of 1.8 km is 57.5 • C, which combined with the thermal properties of the rock gives a heat flux of between 73 and 82 mW/m 2 . The average heat flux from the continental crust is 57 mW/m 2 and from the oceanic crust is 99 mW/m 2 [9]. In addition, the direct use of groundwater geothermal heat pumps for heating individual buildings and a few district heating systems can be found in sporadic cases in large urban areas or agglomerations. ...
Reducing energy costs in Europe is more challenging than before due to extreme price increases. The use of local renewable energy sources is one way to contribute to this effort. In the case of spa resorts, the use of heat from hot springs for therapeutic baths is an option. It is necessary to cool down this thermal mineral water to a temperature acceptable to the human body. However, due to the high mineral content of this water, heavy fouling can be a problem for conventional heat exchangers. The purpose of this study is to identify the suitable cooling technology in terms of required cooling capacity and waste heat recovery capability. The cooling technology was selected on the basis of a literature search. A pilot cooling unit consisting of vacuum cooler and plate heat exchanger was designed and tested in a real spa resort for six months. Both selected technologies have demonstrated the ability to cool thermal mineral water in long-term operation, as well as the possibility to utilize waste heat for domestic hot water heating. However, fouling problems occur in the plate heat exchanger. The vacuum cooler demonstrated greater operational robustness and resistance to encrustation.
... The global energy crisis, and also the war in Ukraine, have made it necessary to use renewable energy sources in order to become independent of the uncertain and unstable Russian fossil fuel markets [80]. Renewable energy sources such as wind energy [81], solar energy [82], hydroelectric energy [83], the energy of oceans [84], geothermal energy [85], biomass and biofuels [86][87][88] are an alternative to coal, petroleum and natural gas, ipso facto contributing to increases in energy self-sufficiency, and also limiting greenhouse gas emissions. The EU is one of the pioneers in promoting decarbonisation and using renewable energy [44]; in 2004, the use of energy derived from renewable sources in the EU amounted to merely 9.6%, whereas in 2020, it reached 37%. ...
The aim of the study was to identify the state of residential buildings in terms of energy consumption and modernisation in Poland against the background of the EU, and to determine factors and activities increasing households′ interest in net-zero energy buildings. In the European Union, we are observing a tendency to increase the energy efficiency of buildings, including residential, and decarbonise building stock by 2050. The objective of the undertaken activities is to reduce energy use and the negative impacts of the use of buildings on the environment. Attaining this objective requires modernising many buildings. This dissertation includes an investigation into the condition of buildings in Poland from the aspect of energy use and the kind of carriers of this energy, and also into another issue: what factors and activities may increase society′s interest in net-zero energy buildings, and in the use of energy from renewable sources in residential buildings. The studies were conducted with the use of the data provided by the Central Statistical Office and EUROSTAT, and also of the reports of the European Commission, the data of the Central Emission Register of Buildings (CERB) and the Odysse–Mure database. An important source of information was also surveys conducted with the application of CAWI (Computer-Assisted Web Interview), and also of PAPI (Paper and Pencil Interview), among 387 households in Poland. For the purpose of analysing the results of the studies, the methods of descriptive statistics, the chi-square test of independence, the ANOVA test of Kruskal–Wallis and the Mann–Whitney U-test were used. The analysis gives rise to the conclusion that, in residential buildings, household′s annual primary energy demand is dependent on the year in which a building was commissioned. Newer buildings can boast smaller heat energy use. Simultaneously, ever more households are undertaking activities that will result in the thermal modernisation of residential buildings. The studies have shown that the development of net-zero energy buildings requires undertaking activities in the scope of introducing allowances and subsidies, and also increasing social awareness in the scope of this kind of building. Interest in buildings using solely renewable energy sources is contributed to by raising energy prices, and also the falling prices of required installations.
... The conventional energy supply is decreasing by the day, and the energy demand nowadays has necessitated seeking more alternative energy. One of the alternative energies is geothermal energy; in its broad term, the thermal energy contained in our planet (Manzella 2017). This energy comes from the Earth's natural heat, primarily due to the decay of uranium, thorium, and potassium (Dickson and Fanelli 2004). ...
Indonesia has high geothermal potential comprising 40% of the world’s potential
geothermal energy, volcanic and non-volcanic systems. Volcanic systems have witnessed more exploration activities for geothermal resources compared to non-volcanic systems. A high potential non-volcanic system in Indonesia is located in the northern part of Konawe, Southeast Sulawesi. Previous research had identified surface temperature anomaly (high temperature) and some surface manifestations for this area, specifically in the northeast part of Wawolesea. However, the source of surface manifestations and permeable zones as an implication of a good reservoir are still unknown. Therefore, this research aims to investigate the permeable zones and geothermal potential in the non-volcanic geothermal system of north Wawolesea by applying lineaments analysis and the fault fracture density (FFD) method. A total of 1694 major and minor lineaments were manually delineated using ArcGIS based on Digital Elevation Model Nasional (DEMNAS). FFD map and rose diagrams displayed the orientation of all lineaments and structures with the major lineaments trending NNE–SSW, whereas the minor lineaments showed irregular distribution and orientation. Field measurements also show the same azimuth orientation for the mapped fractures. Five zones were characterized by high FFD values (2.81–4.54 km/km2). One of the extensively fractured zones (Zone C) is located between Meluhu and Lembo, covering an area of around 19.39 km2. This area is interpreted to be highly permeable and suggestive of a recharge area that contributes to surface manifestation in the Wawolesea. Therefore, the area between Meluhu and Lembo in the northern part of Konawe shows high geothermal potential due to its planar morphology and high FFD values. This study allows an improved understanding of how fracture geometry, distribution and density control the permeability in geothermal reservoirs.
... The density of geothermal heat flux near the Earth's surface on the mainland land-based area is at an average 58 mW/m 2 [1]. During a detailed survey with the use of geophysical instruments in the bore-holes of the Dnipro-Donetsk depression on the territory of Ukraine, it has been specified that at depths of up to 3 -4 km the heat fluxes have a slightly lower potential of heat power of 30 -40 mW/m 2 [2]. ...
A review has been conducted of key trends in the development of geometric topology of geothermal heat exchangers. Authors proposed approaches to improving the designs and network structures for heat-transfer media circulation in the bottom-hole space of oil-and-gas reservoirs. Four geometric topologies of geothermal heat exchangers have been analysed: І – ІІ – rectilinear vertical smooth and finned pipelines; ІІІ – IV – a cluster in the form of a set of smooth and finned single-pipe elements, representing a figure of “squirrel wheel” or “meridian sphere” type. It is shown that the most effective technical solution, which ensures the increase in the coefficient of performance ( COP ) of bore-hole geothermal systems is finning the heat exchanging pipes. For the heat exchangers of І – ІІ type, the calculated increase in COP in comparison with smooth pipes is 40%, and for ІІІ – IV type – 95%. The key parameters influencing the COP of a geothermal heat exchanger are: the radius of fluids draining out during the heat exchange process, the radius of pipelines with circulating heat-transfer medium, the diameter of a cluster heat exchanger, the heat exchange area, the parameters of rocks thermal resistance in the bottom-hole zone of heat-receiving.
... The density of geothermal heat flux near the Earth's surface on the mainland land-based area is at an average 58 mW/m 2 [1]. During a detailed survey with the use of geophysical instruments in the bore-holes of the Dnipro-Donetsk depression on the territory of Ukraine, it has been specified that at depths of up to 3 -4 km the heat fluxes have a slightly lower potential of heat power of 30 -40 mW/m 2 [2]. ...
Abstract. A review has been conducted of key trends in the development
of geometric topology of geothermal heat exchangers. Authors proposed
approaches to improving the designs and network structures for heattransfer media circulation in the bottom-hole space of oil-and-gas
reservoirs. Four geometric topologies of geothermal heat exchangers have
been analysed: І – ІІ – rectilinear vertical smooth and finned pipelines;
ІІІ – IV – a cluster in the form of a set of smooth and finned single-pipe
elements, representing a figure of “squirrel wheel” or “meridian sphere”
type. It is shown that the most effective technical solution, which ensures
the increase in the coefficient of performance (COP) of bore-hole
geothermal systems is finning the heat exchanging pipes. For the heat
exchangers of І – ІІ type, the calculated increase in COP in comparison
with smooth pipes is 40%, and for ІІІ – IV type – 95%. The key parameters
influencing the COP of a geothermal heat exchanger are: the radius of
fluids draining out during the heat exchange process, the radius of
pipelines with circulating heat-transfer medium, the diameter of a cluster
heat exchanger, the heat exchange area, the parameters of rocks thermal
resistance in the bottom-hole zone of heat-receiving.
Studies on terrestrial heat flow, particularly in oil and gas reservoir systems, have gained substantial attention. While the traditional focus was on igneous and metamorphic activities, this chapter focuses on geothermics and thermogenesis in gas reservoirs, emphasizing the fundamental concepts of heat and temperature, subsurface conditions related to heat, and responses of reservoir materials to temperature changes. Geothermics, at its core, explores the source and destiny of terrestrial heat, with “geo-” denoting the Earth and “thermos” signifying heat. It is the study of heat transport and thermal conditions in the Earth’s interior. In practical terms, geothermics extends to the assessment of geothermal resources, examining heat distribution in the Earth’s outer layers and the potential for heat extraction. Moreover, this science has evolved into an applied field, with geothermal energy being a notable application that harnesses the Earth’s heat. In this context, “thermogenesis” encompasses all physical and chemical reactions in the reservoir, including gas generation, thermal gas cracking, and mineral alteration. In essence, this chapter delves into the intricate dynamics of heat and temperature within gas reservoirs, providing valuable insights into geothermics and thermogenesis, and their significance in the energy industry.
Geothermal energy is likely to be a significant contributor in achieving sustainable energy goals and net-zero emissions targets. Within geothermal power plants, heat exchangers play a critical role in harnessing this renewable energy source. However, these heat exchangers encounter significant challenges when exposed to geothermal fluids, including erosion, corrosion, and scaling, which adversely affects their performance and longevity. The current review focuses on surface engineering techniques, particularly coatings, as a highly effective and economically viable solution to address these challenges in geothermal heat exchangers. The review begins by providing an overview of geothermal energy, its significance in the context of sustainability and the important role played by heat exchangers in geothermal power generation, followed by the challenges and their impact on heat exchangers. The subsequent section focuses on surface engineering by coatings and its types employed to enhance the performance of heat exchangers. In the final part, the reader is presented with an overview of the challenges associated with the application of coatings in geothermal heat exchangers and potential future directions in this field. This review offers a detailed understanding of the critical role coatings play in improving the efficiency and service life of heat exchangers in geothermal power plants.
Many countries are using incentives to increase domestic and renewable energy (RE) production, which is important for sustainable development and meeting the rising demand for energy. This also helps achieve zero-carbon emission goals and reduces dependency on foreign sources. Countries have made progress using renewable energy with provided incentives. Along with political and economic regulations, scientific research is crucial in raising public awareness to foster innovation. Through academic studies on renewable energy and policy, countries can create better policies and investments while promoting environmental awareness for a sustainable future. A comparative analysis of academic outputs on incentives and policies for green energy is important. This research examines the link between RE use and academic production. To this end, a bibliometric analysis of scientific publications from Turkey, Germany, France, Spain, and Italy was employed to understand the current state policies and suggest future studies. The academic studies that were compiled with the keywords in the RE policies and measures in the Web of Science database have revealed that academic productions increase quantitatively as RE investments increase. The thematic analysis shows that the maturity in RE use is also reflected in scientific research.
The International Maritime Organisation focuses on decarbonising the operational phase of a ship's life cycle. However, shipbuilding contributes to a significant amount of greenhouse gas emissions and air pollutants and has negative impacts on society. Holistic and transdisciplinary studies of the shipbuilding energy sector are lacking and a holistic approach is needed to discuss the potential of measures and tools to improve the shipbuilding industry with zero emissions. This study is an interdisciplinary approach to provide trends, recommendations and policies for decarbonisation of the shipping industry from a life cycle perspective. Taking into account a holistic and transdisciplinary approach, the energy sector in shipbuilding is categorised into an energy supply system, an energy economic system and an energy ecosystem, and the main disciplines for improving energy efficiency and promoting “zero emissions” for shipyards are identified, measures and tools within each discipline are proposed, and their mitigation potential and key issues for improving energy efficiency and reducing air emissions from shipyard activities are discussed. The case study highlights the economic, environmental and sustainability benefits of implementing the proposed modern energy system in an Italian shipyard. Although there is no silver bullet to eliminate air emissions in the shipbuilding industry due to the complexity, the different reduction potentials, the costs and the relationship and interaction between measures and tools, the implementation of the energy management framework can accelerate the transition to a zero-emission shipbuilding industry.
