Potential Energy Resource Research Articles

Investigation of creep and transport mechanisms of CO2 fracturing within natural gas hydrates

Natural gas hydrates (NGH) are considered as a potential energy resource in the future because of its dramatic energy reserves. NGH formation owns the characteristic of viscoelasticity, to some extent behaves both like liquid and solid. Ignoring the viscoelastic properties of NGH can lead to inaccurate prediction of related characteristics. In 2020, horizontal-well drilling technology was adopted to improve the stimulation performance of NGH reservoirs in the Shenhu area of China. This indicates that it is possible to apply hydraulic fracturing or CO2 fracturing in the reservoir reconstruction of NGH. CO2 fracturing can generate more fracture networks and connect micro fractures. Additionally, CO2 can be stored geologically and integrated with injection, production, and storage. This study provides a relatively detailed demonstration of the formation and basic mechanical properties of NGH. Then, a comprehensive overview of potential NGH production enhancement methods is conducted. Finally, an evaluation method for dual conductivity considering creep effect is proposed, and the results show that the creep effect of NGH can reduce the conductivity of fractures and matrices. Thus, it is of great importance to investigate the viscoelastic properties of NGH formation, for the long-term prediction of the geo-mechanical response to gas extraction.

Assessment of Wind Resource and Its Energy Potential in Three States of Northwest Nigeria

The growing need for clean energy to address the environmental issues caused by the usage of fossil fuels results to the need for Nigeria to develop an alternative energy from untapped wind which is in abundance in the region. The aim of this study is to evaluate wind power potential and wind energy resources of three locations (Kaduna, Kano and Katsina) of northwestern part of Nigeria. The Nigerian Meteorological agency (NIMET) provided the wind speed data spanning 25 years (1996-2020). In the analysis, Weibull two-parameter statistical model was used. The distribution of wind speed across Nigeria demonstrates that some areas in the North are equipped to generate wind. Microsoft excel was used in analyzing the wind speed data obtained. In addition, evaluation of the region’s wind energy resources shows that Kano recorded the highest potential, with WPD of 443.03 Wm-2 at 10m AGL with annual WED of 4.921 kWhm-2day-1 while Kaduna recorded the lowest potential of 198.43 Wm-2 with annual WED of 2.093 kWhm-2day-1. As a result, Kaduna is found to be ideal for small scale wind power generation, while Kano and Katsina may be suitable for large scale wind power generation.

The Politics of Indonesia’s Renewable Energy Policy

Indonesia's natural landscape of land and sea is a very abundant energy resource. Indonesia has enormous opportunities because of its gift of natural resources, which can be used as renewable energy sources. This study comes from secondary data to support arguments, and data collection uses library research by collecting material from books, journals, laws and regulations, and other literature. The data analysis technique uses descriptive language by describing the data, which is then analyzed to describe an explanation of the data. This research explains the potential of Indonesia's energy resources, especially renewable energy, and the politics of Indonesia's renewable energy policy, which targets an energy mix of 44% by 2030. This research concludes that renewable energy policy has obstacles, including weak control. Renewable energy resource exploration technology, expensive machines for exploring energy resources, and the formulation of laws related to new renewable energy have not yet become a priority.

Pore-scale visualization of hydrate dissociation and mass transfer during depressurization using microfluidic experiments

Natural gas hydrate is a potential low-carbon energy resource. Extracting this resource efficiently remains a challenge, due to the intricacies involved in multiphase reactive transport during hydrate dissociation. This study employs microfluidic experimental techniques to observe pore-scale interactions during depressurization-induced hydrate dissociation, utilizing high-resolution spatial and temporal imagery. Supervised machine learning algorithms segmented these microscopic images, enabling the analysis of phase saturation changes and hydrate dissociation rates. The study identifies two distinct hydrate forms in microfluidic chips: hydrate films and crystals, each exhibiting unique dissociation characteristics. Hydrate films decomposed rapidly in response to pressure reductions below equilibrium with the dissociation rate of O(10−1 %/s) under stationary gas–water conditions. When considering gas–water migration, the gas encapsulated in the hydrate film will be displaced by water, leading to a reduced dissociation rate. The hydrate crystal dissociation is much slower with the dissociation rate of O(10−3 %/s) under stationary gas–water conditions compared to the hydrate film, hindered by mass transfer limitations. Gas-water migration can enhance crystal dissociation. The formation and expansion of gas microbubbles under depressurization accelerated hydrate dissociation within a confined temporal and spatial range, which was known as the self-promotion mechanisms. Significantly, depressurization-induced gas slug flow increases the dissociation rate by more than one order of magnitude, compared to that in stationary gas–water conditions. The depressurization process played a significant role, not only by facilitating thermodynamic feasibility for hydrate dissociation but also by inducing the critical gas slug flow. These results of the present study provide theoretical guidance for improving natural gas hydrate production efficiency.

Evolution Characteristics of the Strength and Dilation Parameters of Gas Hydrate-Bearing Sediments and a Modeling Study

Gas hydrate has gradually become a new potential energy resource. However, some engineering and environmental problems related to the mechanical properties of gas hydrate-bearing sediments (GHBS) during gas recovery may occur. Many studies have been carried out on the basic mechanical properties of GHBS samples based on laboratory tests, but their evolution characteristics and suitable models require further research. Based on a series of data analyses of published laboratory experimental results on GHBS samples with different hydrate saturations under various confining pressures, the evolution characteristics of strength and dilation parameters were investigated. It was found that cohesion (c) increases quickly to a peak value and then decreases gradually to a residual value with an increasing plastic shear strain, and the samples with higher hydrate saturations have higher initial values, peak values, and residual values of cohesion (c). The internal friction angle (φ) increases quickly with increasing plastic shear strain and then becomes stable at a residual value for all the samples with different hydrate saturations. The dilation angle (ψ) increases from negative to positive values with increasing plastic shear strain and then becomes stable at a residual value. These characteristics are likely to be related to the compaction occurring at the early stage of compression before expansion due to dilation. In this paper, a non-linearly fitted model is proposed considering the evolution of the mechanical parameters, and the verification tests show that the proposed model can simulate the stress–strain behaviors of the GHBS samples well. This model is also adopted in the stability analysis of submarine slopes containing hydrate reservoirs. The analytical approach is developed, accompanied by the strength reduction method.

STATUS AND PROBLEMS OF DEVELOPMENT OF “GREEN” ECONOMY IN AZERBAIJAN

According to domestic and international experts, the most promising areas for the development of the “green economy” in the Republic of Azerbaijan (AR) are energy, transport and agriculture [1]. In recent years, numerous studies have been carried out in the AR to study the existing potential in the field of development of alternative and renewable energy. As a result of the research, the presence of large wind, solar and hydropower potential, biogas and thermal energy resources in the republic was revealed. In general, the level of opportunities for the development of alternative and renewable energy infrastructure in Azerbaijan can be compared with such countries as Denmark and Germany. Keywords: green economy, sustainable development, energy, energy efficiency, renewable energy sources, transport, agriculture.

Research on Wind Turbine Location and Wind Energy Resource Evaluation Methodology in Port Scenarios

Wind energy is widely distributed in China as a renewable energy source. Aiming to alleviate the issues resulting from fossil fuel consumption faced by developing and developed countries (e.g., climate change) and to meet development needs, this study innovatively proposed methods for the location selection of wind farms and wind turbines in port areas based on the fuzzy comprehensive evaluation method. Considering that the wind turbine location is crucial to wind power generation, this paper focuses on locating wind turbines within a specific set of sea ports. The primary objectives of this paper are to evaluate the potential of wind power generation under different port scenarios and develop a method for assessing the potential of wind energy resources in wind farm areas. Firstly, a method is proposed for identifying the boundaries of wind farms in the port areas and locating wind turbines at sea ports. Furthermore, this study used the National Aeronautics and Space Administration (NASA) wind speed database to test the proposed method with the real-world wind power projects of the Ports of Tianjin, Shanghai, Xiamen, Shenzhen, and Hainan, which are top ports within five major coastal port clusters in China. It is found that the potential power generation capacity of the wind power farms at the above ports is 30.71 GWh, 19.82 GWh, 16.72 GWh, 29.45 GWh, and 24.42 GWh, respectively. Additionally, sensitive results for different types of wind turbines are conducted in the following experiment. The results of this study are fundamental for enriching the research of evaluating wind energy resources of sea ports and promoting the development and use of clean energy in practical environments. Further, the method proposed in this study is essential for optimizing the location and construction of wind turbines, which may help ports in adopting a low-carbon and green development path, thereby mitigating air pollution, and promoting sustainable development.

What Advantages Arise from the Shift Towards Sustainable Energy Sources in Resource-Rich Economies? Empirical Insights from Azerbaijan

Azerbaijan, a nation with abundant petroleum resources, aspires to harness the untapped potential of the Caspian Sea's renewable energy resources. The aim for the immediate future is to meet not only domestic energy requirements, but also to establish the nation as a green energy exporter. The nation expects to develop power installations utilizing renewable energy over the forthcoming decades to satisfy a portion of its domestic consumption and also cater to the European market. As part of this colossal project, Azerbaijan anticipates collaborating with international partners to install a 4-gigawatt (GW) power cable traversing the seabed of the Black Sea. The successful realization of these ambitious projects would bolster Azerbaijan's economic sustainability during its post-petroleum phase, while simultaneously enabling a reduction in carbon emissions, offering regional and global benefits. This manuscript seeks to probe the multidimensional implications—political, economic, sociocultural and environmental—of this shift towards wind-derived green energy for Azerbaijan and other nations in the region.

Geographical information system based assessment of various renewable energy potentials in Nigeria

Nigeria’s energy transition plan is hinged on increasing the energy mix from renewable energy sources. An understanding of where the potentials of these renewable energy sources lie is very crucial to enhance quality and timely policy formulations, interventions and proper decision making. This paper aims at providing a holistic assessment of the potentials of key renewable energy resources; solar, wind, biomass and small hydro in Nigeria using ArcGIS; a geospatial analytical platform that provide data and visualizations of these potentials across the country. This paper focuses on the Inverse Distance weighting methodology which overlays various map shapefiles and spreadsheets containing relevant data such as; waterlines and water areas, road and rail networks, crop production, longitude and latitude, wind speeds, solar irradiation, elevation and other relevant map data, shape files for all the Nigerian states and local governments. These data are geo-processed to align the results to the exact locations as provided by their geographical positions stem coordinates. These interpolation results are further reclassed within standard limits for the various output parameters such as crops, forest areas, built-up areas, water bodies, shrubs/grasslands, barren lands and waterbodies to reveal suitability areas for siting the various renewable energy power generating plants.

Utilization of Small Solar-ORC Integrated with Organic PCMs in Hungary Condition

Regarding solar energy resource potential, Hungary has a daily total of around 3.2 to 3.6 kWh/m2 and an annual total of approximately 1168 to 1314 kWh/m2. It makes it a good position for solar thermal collectors in combination with an ORC system. In this study, the authors investigated solar thermal as a heat source to generate electricity, with ORC utilizing R245fa as a working fluid. Due to the limited time for utilizing solar thermal by ORC, while the highest electricity usage is at night, heat storage is carried out by integrating a TES-evaporator using organic PCM.

Unlocking the potential of renewable energy and natural resources for sustainable economic growth and carbon neutrality: A novel panel quantile regression approach

As the world grapples with the dual challenge of fostering sustainable economic growth and achieving carbon neutrality, the role of renewable energy, urbanization, and financial development in shaping environmental outcomes in South Asian nations becomes increasingly critical. In this pioneering study, we delve into the heart of South Asia, encompassing a diverse range of nations – Afghanistan, Bangladesh, Bhutan, Pakistan, Sri Lanka, Nepal, the Maldives, and India – each chosen for their strategic geographical significance and the rich availability of pertinent data, offering a unique lens into the region’s energy and economic dynamics. This research uses panel quantile regression analysis to examine the relationship between the renewable energy consumption, broad money, urbanization, and natural resources and their effects on carbon emissions and economic development in South Asian (SAARC) nations. Fixed-effect panel quantile regression analysis was used to adjust for geographical variability. This study aims to investigate how urbanization, broad money, natural resources, and renewable energy affect economic growth and carbon emissions. According to our research, renewable energy consumption significantly and negatively affects CO2 emissions, especially in the distribution’s higher quantiles. Urbanization has a positive and significant effect on GDP, whereas natural resource rent has a positive impact on GDP and CO2 emissions. Broad money boosts GDP in the lower quantiles while having a negative impact in the higher quantiles. These findings show that in order to combine economic development with environmental sustainability, governments must concentrate on boosting the use of renewable energy sources and encouraging sustainable urbanization. Our policy implication is that policymakers should prioritize policies aimed at promoting renewable energy consumption and sustainable urbanization, which can help mitigate the negative environmental impact of economic growth in the SAARC region.

Solar Energy Resource Potentials of the City of Arkadag

The article obtained systematized, scientifically substantiated gross, technical, economic, and environmental energy resource potentials from the introduction and use of solar energy technologies. The technical, economic, and environmental priorities of power plants were assessed in terms of energy efficiency, fuel economy, and the environmental impact per square meter from conversion to thermal and electrical energy in the city of Arkadag. The calculated results are, kWh/m2 per year: gross resource potential of solar energy - 1844.6; the technical potential for conversion into thermal and electrical energy is equal to - 1256.44 and 242.44; economic - 502.6 and 96.98 kg fuel equivalent/m2 per year; environmental reduction in emissions of various harmful substances into the environment when using solar photovoltaic modules in the city of Arkadag will be: with annual electricity generation per m2 - 242.44 kW·h, annual fuel consumption savings - 96.96 kg. e., the reduction in emissions will be, kg per year: SO2 – 2.0; NOx – 1.1; CO – 0.14; CH4 – 0.29; CO2 – 155.0; solids – 0.21; when converted into thermal energy per m2 and annual production of 1256.4 kW·h, annual fuel savings are 502.6 kg of fuel equivalent; emission reduction will be, kg per year: SO2 – 10.4; NOx – 5.6; CO – 0.73; CH4 – 1.53; CO2 – 803.5; solids – 1.1. Empirical equations (1-5) have been obtained taking into account the gross, technical, economic, and environmental resource potentials of solar energy in the city of Arkadag, it is possible to carry out energy and environmental forecasting when drawing up a feasibility study.

Assessment of Tidal Current Energy Resources in the Pearl River Estuary Using a Numerical Method

In this paper, a numerical method is employed to assess tidal current energy resources in the Pearl River Estuary, China. The numerical model for tidal current simulation in the estuary is developed based on the MIKE 21 model, which enables numerical simulations in estuaries, coastal areas, and oceans. The model has a grid resolution that varies from about 2500 m at the open boundary to 500–1000 m inside the estuary. Extensive model validation is performed by comparing the model predictions with field observations of tidal level and velocity at various stations in the Pearl River Estuary. The tidal characteristics are thoroughly analyzed. Energy fluxes and power densities are calculated along selected cross sections to evaluate the feasibility of tidal energy development in the Pearl River Estuary. The results indicate that the distribution of annual average tidal current power density in the Pearl River Estuary generally aligns with the spatial distribution of tidal currents. The annual average power density of tidal energy is typically below 0.10 kW/m2. The theoretical potential of tidal current energy resources in the Pearl River Estuary is assessed to be approximately 11,000 kW.

Sunny City - Arkadag

Sunny City - Arkadag

Моdern heat and steam supply systems of industrial enterprises using deep utilization of the technological steam energy potential

Steam supply systems of industrial enterprises, as a type of heat supply system, are a large consumer of primary energy in national energy balances. In turn, due to the specificity of thermodynamic steam processes, steam supply systems of industrial enterprises in practice have significant unused potential of secondary energy resources (SEP). Modern steam supply systems should be built exclusively when evaluating their exergetic efficiency, which will make it possible to evaluate the effectiveness of such systems grossly in all elements of the life cycle of the project: energy, economic, ecological and even social. The article shows modernized thermal schemes of steam supply systems, for which it is possible to achieve additional electrical power at the level of 135-250 kW/(kg/s) when devices with a relative internal efficiency of up to 60-70 % are operating. In combination with an increase in the percentage of condensate return and the utilization of secondary energy resources (SRP), the increase in energy efficiency of the system is 2-4 %, and the absolute value of exergetic efficiency is 16-22 %, taking into account the exergetic efficiency of the boiler unit. Low-potential "tail" consumers: the heating system, the hot water supply system - increase the exergy efficiency of the steam supply system of an industrial enterprise by 0.2-0.6 % in the case of joining on the steam side of secondary boiling. Any processes of generating electrical energy are associated with obtaining a significant amount of thermal energy, and must be accompanied by its utilization; enterprises that use steam as an energy carrier (the same applies to energy enterprises such as thermal power plants and nuclear power plants) for the deep utilization of hydroelectric power plants must have thermal energy consumers in their composition, which can act as communal household consumers (if they exist), as well as new technological consumers of thermal energy.

Archimedean Screw Based Micro Hydro Power Plant (MHPP) Prototype with Turbine Elevation Angle Parameters

Electrical energy has a very important role in human life, but the electricity supply still needs to meet society’s needs fully. Many potential energy resources can be converted into electrical energy. One of the potential energy resources is the flow of water, which can be used for micro-hydro power plants in remote areas. This paper presents the results of an analysis of a prototype Micro Hydro Power Plant (MHPP) using a 3-blade turbine with a gearbox ratio of 2.8:1. The purpose of the analysis is to determine the greatest value of voltage, current, power, rpm, torque, and efficiency based on variations in the angle of the turbine tilt of 20°, 25°, 30°, and 35° at a water debit of 2.91 l/s and a generator in the form of BLDC 3 phase. The measurement results and data analysis found that the turbine tilt angle of 20° produced the greatest voltage, rpm, torque, and efficiency values. This is because the increase in the angle of inclination of the turbine results in an addition to the volume of the bucket so that the speed of the water flow in the turbine increases. As a result of the addition of this water flow, the turbine becomes heavier to rotate so that the efficiency value decreases.

Reviewing the UK's exploited hydropower resource (onshore and offshore)

Hydropower and tidal energy are valuable renewable energy resources that can assist in meeting the United Kingdom's net zero greenhouse gas emissions target. Existing studies have attempted to assess what the future energy resource potential is that can be harnessed from the water environment. Although schemes harnessing this energy, particularly hydropower, have been widely developed across the UK, few of the resource assessments account for already operational sites. This study takes the initial step required to holistically assess an accurate available potential by determining where and how much of the combined resource has already been exploited.During the research it was noted that the extent of development in terms of installed capacity and locations of sites has been poorly recorded. Data collection shows that there is not a single comprehensive database of hydropower and tidal energy schemes. This study has therefore addressed this research gap collating operational hydropower and tidal energy projects.This research determines the total installed capacity of hydropower is 4.66 GW, with 82 % of the powerhouses' locality identified. The contribution of tidal energy is much smaller at 10.63 MW. This research now makes it possible to fully understand the existing hydropower picture for the UK for the first time, allowing for more accurate resource assessments to be undertaken and for a better understanding of what the current contribution of these renewable energy sources (approximately 14 %) can be towards meeting the UK's energy demand (averaging 33 GW in 2020).

The theoretical approach of the solar organic Rankine cycle integrated with phase change material for the Hungarian region

AbstractHungary is not only dependent on imports of natural gas and fossil fuels, but Hungary is also the lowest in renewable energy utilization; otherwise, only 11.3% compared to other Central European countries in renewable energy utilization, above 13%. The percentage of renewables in power generation quadrupled from 8% to 16% between 2010 and 2020, with most of the gains coming from the rapid expansion of solar energy, particularly after 2016. Regarding solar energy resource potential, Hungary has a daily total of around 3.2–3.6 kWh/m2 and a yearly total of about 1168–1314 kW.h/m2. This makes it a suitable location for putting solar thermal collectors in conjunction with an organic Rankine cycle (ORC) system. In this study, the authors analyzed solar thermal as a heat source to generate electricity with ORC using two types of working fluids (R245fa and R123). Hungary's weather data for a whole year is used as primary data to look for solar radiation characteristics and ambient temperature. Based on the general solar collector equation, the parabolic tube collector was selected as the best solar collector to utilize solar radiation by producing a maximum heat of around 654.68 kW. Therefore, the evacuated flat plate collector was selected as the solar collector that can produce the maximum outlet temperature of around 372.15 K with a similar size aperture area. Producing a temperature output from the solar collector for heat transfer in the ORC system and from the performance showed that R245fa resulted in better Wnet performance compared with R123 with values of 45.82 and 28.17 kW, respectively, under the same solar collector. Meanwhile, the material suitable for the thermal energy storage‐evaporator combination is organic phase change material using N‐Octacosane, which in the same temperature range (350–375 K) has the smallest ζ(T) value (1.08–1.103), so the mass required for the system is very efficient.

Mapping of the Structural Lineaments and Sedimentary Basement Relief Using Gravity Data to Guide Mineral Exploration in the Denizli Basin

The Aegean Graben System is a complex tectonic structure in Western Anatolia and the Denizli Graben is a member of this system that hosts many geothermal springs, ore deposits, and travertine areas. In this study, the gravity data were analyzed to determine the subsurface geological structures and the depth model of the basin. The Bouguer gravity anomaly has a NW–SE pattern that is consistent with the general trend of the Denizli Basin. The pre-Neogene basement depths range from 0.1 km to 2.3 km. The Denizli Basin is composed of the Çürüksu Basin and the Laodikia sub-basin. The basins have undulated structures with many depressions; the deepest depression region is in the northern part of the Çürüksu Basin, which is close to the Pamukkale Fault Zone. In addition, the new gravity lineament map was obtained by using new-generation edge detection techniques: the tilt angle of the horizontal gradient amplitude (TAHG), and fast sigmoid-edge detection (FSED) of gravity data. The new proposed lineament map shows that the Denizli Basin has complex structures consisting of NW–SE, E–W, and NE–SE trending lineaments, and the major NW–SE trending faults and NE–SW trending lineaments control the main structural configuration. The uplifts and depressions in the basin deposit and the intersection area of lineaments are promising prospective areas for mineral deposits and have energy resource potential.

Tidal energy extraction modifies tidal asymmetry and transport in a shallow, well-mixed estuary

Tidal energy extraction is increasingly being studied as a potential renewable energy resource in estuaries worldwide. Although it is understood that energy extraction via tidal stream turbines can modify currents and transport within estuaries, it is not clear how the underlying nonlinear physical mechanisms dictating tidal hydrodynamics are modulated. This research investigates the influence of a hypothetical tidal stream turbine array on barotropic tidal processes in a shallow, well-mixed system: the Piscataqua River – Great Bay (PRGB) estuary, using a numerical model. The modeled turbine farm includes 180 turbines which would extract an estimated 44.7 GWh of energy, annually. The tidal hydrodynamic model for the existing condition is validated with in-situ observations of currents and water level before analyzing tidal asymmetry and transport with and without tidal turbines. Results indicate that the tidal turbine array will decrease tidal elevation and current magnitudes system-wide, but generally reduce ebb currents and transport more than flood over most of the estuary footprint, thereby diminishing tidal asymmetry. The smaller asymmetric distortion compared to the no-turbine case is attributed to reductions in the storage volume of water over the estuary’s extensive tidal flat regions between low and high waters which decreases the associated nonlinear intertidal storage mechanism up to 25%. This leads to weakened ebb dominance over estuary sections from the mouth to mid-reaches, where depths are deep enough to keep the combined nonlinear shallow water and frictional effects from asserting control over the storage mechanism. Even in upstream shallow regions where depth-dependent friction controls asymmetry in both cases, the frictional mechanism is reduced only by 10% with turbines. Some environmental considerations of this work are discussed, with focus on sediment transport, water quality, and ecology.