Energy and water have faced important levels of conflicts in the last 20−25 years in Chile. However, the way that they have been politically addressed in the last decade differs. These differences emerge from how these fields have been historically configurated, impacting on how the policy problems and policy options have been framed. Using thematic analysis of 93 interviews and documentary analysis, this article analyzes by contrasting two participatory processes which nourish the formulation of the energy and water policies in Chile in 2014−2015. It seeks to understand the factors that may influence why the development, impact and inclusion of new voices in public policies related to water and energy have been different, and how that can impact the water−energy nexus. Five factors emerge as determinants in this difference: structure of use, number of actors, governance and institutional framework, elite conformation, and legal framework. These factors impacted the policy processes an... [more]

To improve the proficiency of energy systems in addition to increasing the usage of renewable energies, thermal energy storage (TES) is a strategic path. The present literature review reports an overview of the recent advancements in the utilization of salt hydrates (single or binary mixtures) and composites as sorbents for sorption heat storage. Starting by introducing various heat storage systems, the operating concept of the adsorption TES was clarified and contrasted to other technologies. Consequently, a deep examination and crucial problems related to the different types of salt hydrates and adsorbents were performed. Recent advances in the composite materials used in sorption heat storage were also reviewed and compared. A deep discussion related to safety, price, availability, and hydrothermal stability issues is reported. Salt hydrates display high theoretical energy densities, which are promising materials in TES. However, they show a number of drawbacks for use in the basic... [more]

Water content is an important factor in the deformation-destruction process of coal bodies. To analyze the influence of water on the creep acoustic emission (AE) characteristics of coal rock surrounding a borehole, we conducted graded loading creep AE tests of single-hole specimens with different water contents (0%, 4%, 8% and water-saturation) under uniaxial loading. The findings include the following: the water content affects the creep mechanical properties of the coal body around a borehole. The creep transient strain and steady-state strain increased exponentially with rising water content; the saturated specimen showed the highest increase, reaching 44.5% and 28.6%, respectively. The specimen water content affected the cumulative ringing count (CRC) and the axial strain during creep. The axial strain increased with rising water content, the CRC increased linearly with rising axial strain. The higher the water content, the greater the CRC rise. At different stress levels, the CRC... [more]

Renewable energy is one of the most discussed topics nowadays, more so than traditional combustible energy sources and nuclear energy. There is an apparent need to study its public acceptance and the general public’s knowledge about it, especially in the context of more advanced inventions, such as smart grids, energy storage, or photovoltaic inverters. In this research, the results of a custom survey and those of several types of public social media datasets were processed to gain insights into the acceptance and awareness of these technologies. The second aim was to investigate technologies and related public opinions about manufacturers. One social media dataset was processed by a novel technology based on automatic data collection from popular social media sources, blogs, forums and public news. All the collected and anonymized data were restored in a custom-made data lake (unstructured database) and analyzed by a natural language processing (NLP) engine to extract the required inf... [more]

The aim of the article is to present and analyze the implementation of intelligent lighting within the concept of smart energies and smart cities. Motivation and research hypothesis: Electricity consumption in the world is based largely on non-renewable energy. Until these full changes, it is necessary to look for opportunities to save and use it efficiently. Today’s cities are increasingly implementing the smart concept, of which smart energy is one area. One of the smart city elements implemented by cities is smart energy. Within this framework, a supported concept is the replacement of traditional lighting with LEDs (Light-Emitting Diodes), which contributes to energy and cost savings and reduces the pollution of the sky with artificial light, while increasing the efficiency of urban lighting. Positive effects of modern solutions include reduced lighting expenses and increased safety of residents. Methods and results of the research: The authors chose the case study method for their... [more]

The thermal energy conversion of natural gas (NG) using appropriate configuration cycles represents one of the best nonrenewable energy resources because of its high heating value and low environmental effects. The natural gas can be converted to liquefied natural gas (LNG), via the liquefaction process, which is used as a heat source and sink in various multigeneration cycles. In this paper, a new configuration cycle is proposed using LNG as a heat source and heat sink. This new proposed cycle includes the CO2 cycle, the organic Rankine cycle (ORC), a heater, a cooler, an NaClO plant, and reverse osmosis. This cycle generates electrical power, heating and cooling energy, potable water (PW), hydrogen, and salt all at the same time. For this purpose, one computer program is provided in an engineering equation solver for energy, exergy, and thermo-economic analyses. The results for each subsystem are validated by previous researches in this field. This system produces 10.53 GWh electrica... [more]

This paper describes an ejector model for the prediction of on-design performance under available conditions. This is a direct method of calculating the optimal ejector performance (entrainment ratio or ER) without the need for iterative methods, which have been conventionally used. The values of three ejector efficiencies used to account for losses in the ejector are calculated by using a systematic approach (by employing CFD analysis) rather than the hit and trial method. Both experimental and analytical data from literature are used to validate the presented analytical model with good agreement for on-design performance. R245fa working fluid has been used for low-grade heat applications, and Engineering Equation Solver (EES) has been employed for simulating the proposed model. The presented model is suitable for integration with any thermal system model and its optimization because of its direct, non-iterative methodology. This model is a non-dimensional model and therefore requires... [more]

The aim of the article is to identify and assess the relationship between the investment attractiveness of regions for agricultural enterprises and the energy factor. Classical theories of the location of agriculture emphasise the importance of the market factor. The energy factor has so far been ignored, despite the global trend related to the increasing importance of production scales and rising energy consumption in agriculture. There are also no methodological proposals that allow a comprehensive assessment of the investment attractiveness of regions for agricultural enterprises, taking into account the leading location factors. The article presents the author’s methodological model based on the weight-correlation method of valorisation of investment attractiveness of regions for economic entities that invest in agricultural production. It contains a sub-aggregate describing the energy factor. This proposal is a contribution to the theory of the location of agriculture in the field... [more]

Recently there has been an ongoing discussion about energy security. This has been caused by tensions affecting international relations, and the emergence of new geopolitical threats. As one of the main sources of primary energy, natural gas is an obvious subject of interest in this discussion. In Europe, the natural gas market is rapidly evolving, which has resulted in a lack of clarity regarding who is responsible for the security of the gas supply. It is not clear now how to measure the security of the gas supply in economic estimates and by whom that security should be financed. In this paper, the authors present an approach which can be used for valuation of energy security concerning the security of natural gas storage using stochastic modelling based on the mathematical model of the “Newsvendor problem”. The valuation is made from the point of view of countries and considers their individual attitudes to the risk of disruption of deliveries, which is a novel approach to the prob... [more]

The purpose of this study is to analyze the evolution of the scientific research regarding the relationship between energy and economic growth, in order to reveal preferred topics and less approached themes. We conducted an occurrence and cluster analysis, followed by a correspondence analysis using articles published between 1979 and 2019 in journals indexed in the Web of Science. The analysis was split into three periods taking into account the major economic and energetic milestones. The analysis focused on distribution of the topics studied both by years and by journals. The research revealed some major trends: there has been an explosive increase in studies based on Asian countries over the three periods as concerns for sustainable development intensified, and environmental issues were associated with research on the relationship between energy and economic growth. Even if the journals cover different scientific areas, during the last 10 years they contain articles with very simil... [more]

Climate changes are nowadays reality and affect all aspects of everyday life. One of the places where these changes influence the society the most is the Brazilian Ceará region and Jaguaribara basin that suffer long-lasting, devastating drought cycles. They have a dramatic negative impact on local economy, forcing change in business models. This work presents the valorisation of wastes and residues from local fish, prawns, and the vegetable-cultivation industry via biogas production forced to adapt to these new circumstances. Along a single year, as much as 189.74 tonnes of wastes and residues can be processed by the biogas production facility, producing as much as 94 GJ of cooling energy and 1 tonne of biofertiliser monthly. Even for such a small biogas production facility, the NPV is positive already after 11 years; its IRR is 6.2%, and accumulated ROI for 20 years of operation is as high as 77.8%. This work demonstrates that a valorisation of industrial wastes and residues via bioga... [more]

Photocatalysis is a classical solution to energy conversion and environmental pollution control problems. In photocatalysis, the development and exploration of new visible light catalysts and their synthesis and modification strategies are crucial. It is also essential to understand the mechanism of these reactions in the various reaction media. Recently, bismuth and graphene’s unique geometrical and electronic properties have attracted considerable attention in photocatalysis. This review summarizes bismuth-graphene nanohybrids’ synthetic processes with various design considerations, fundamental mechanisms of action, heterogeneous photocatalysis, benefits, and challenges. Some key applications in energy conversion and environmental pollution control are discussed, such as CO2 reduction, water splitting, pollutant degradation, disinfection, and organic transformations. The detailed perspective of bismuth-graphene nanohybrids’ applications in various research fields presented herein sho... [more]

Energy sustainability constitutes an important goal for development, as declared at the global and the European levels. Some conditions decisive for energy performance, as suggested by the Environmental Kuznets Curve (EKC) hypothesis, may be specified by the sectoral structure of production, as industries vary in the intensity of energy consumption. Nevertheless, sustainability is not automatically induced along with economic development and it is important to identify its determinants. The aim of the study is to empirically verify whether the sectoral structure of an economy differentiates energy sustainability within 28 European Union member states (the EU-28). To fulfil the task, a static approach was adopted and such taxonomic methods as the Ward agglomeration method and linear ordering based on the Hellwig synthetic measure were used. The hypothesis concerning the essential role of structural features in energy achievements was verified by a one-way analysis of variance. Our resul... [more]

Developments, trends, business climate, conditions, factors influencing the efficiency and results of mergers and acquisitions (M&A) in the energy sector are explored in this research. PESTLE (political, economic, social, technological, legal, environmental) analysis was performed in order to determine the driving forces of M&As in the energy industry. Considering the motivation and main questions of the study, a sample of global M&A deals that have occurred during the period 1995−2020 has been analyzed. DataStream 5.1 database by Thomson Reuters was employed to identify the sample of global energy companies that took over another company in the period 1995−2020. According to the research, while the role and presence of M&As in the energy industry are increasing, the purpose of the M&A deals has changed remarkably. During 1995−2010, most M&A events were conducted in order to explore synergies and benefit from cost reduction. Since the last decade, firms are pursuing M&As in the search... [more]

The aim of this scientific research is to experimentally determine the exergy losses of a ground heat pump and further optimization for more efficient use of operating modes and improvement of individual structural elements. In addition, it is proposed to use photovoltaic panels as a backup power source for the experimental installation under study. The exergetic losses are calculated, not only for the ground heat pump itself, with R407C refrigerant. The research methodology consists in a comprehensive assessment of exergetic flows, their optimization using new methods of approximation of piecewise linear functions, and the development of prerequisites for the use of anergy as one of the components of a new type of analysis of the efficiency of low-potential energy sources. As a result of processing the experimental data, the values of Coefficient of performance (COP) 4.136, exergetic temperature for the lower heat source 0.0253 and for the upper heat source 0.155, exergetic efficiency... [more]

In 2016, a law was introduced in Poland that required management bodies of energy companies owned by the state and a municipality to adopt management goals. The remuneration of the board members of these companies depended on the extent to which these goals were implemented. The challenge was that profit became an end in itself. The purpose of this article is to describe the process used to set up strategic goals on the basis of balancing capital within energy companies, which demonstrates a positive impact on the effectiveness of these companies. The solution proposed in this article is an alternative to using profit as the sole measure. The article consists of three parts. The first part is a review of the literature on management goals and how they relate to various economic measures—the main conclusions of this literature review were that, despite many attempts, we were not able to (1) clearly define the purpose of a company and (2) find an indisputable measure of the degree to whi... [more]

Recently, the depletion of fossil fuel reserves and the harmful environmental effects caused by burning fossil fuels have signified the supreme importance of utilizing sustainable energy reserves such as geothermal and solar energies. The advancement of the Organic Rankine Cycle as a clean energy generation path by researchers has gained momentous demand for its commercialization. The sole Organic Rankine Cycle can produce a large amount of energy in contrast to other power production cycles. To make this clean energy recovery sustainable, liquefied natural gas cold energy can be utilized through regasification to integrate the Organic Rankine Cycle with the anti-sublimation carbon dioxide capture process, merging the biogas setup. Liquefied natural gas cold energy recovery has paramount importance with aspects of energy economy and environment preservation. Liquefied natural gas regasification in shell and tube heat exchangers poses a minimal freezing risk and is high duty. Anti-subli... [more]

Lithium-ion batteries (LIBs) have circumvented the energy storage landscape for decades. However, safety concerns about liquid−electrolyte-based LIBs have challenged their mobilization. Lithium polymer (LiPo) batteries have gained rising interest due to their high thermal stability. Despite an array of commercially available LiPo batteries, limited studies have ventured into modeling. Numerical simulations allow low-cost optimization of existing battery designs through parameter analysis and material configuration, leading to safer and more energy-efficient batteries. This work examined the electrochemical, thermal, and thermal runaway behavior of a lithium cobalt oxide cathode, graphite anode, and poly(vinylidene fluoride-hexafluoropropylene) electrolyte pouch-type LiPo battery using COMSOL Multiphysics®, and validated results with experimental data. The simulated potential curve exhibited strong agreement with experiment data, while the temperature profile during discharge displayed... [more]

This paper presents an analysis and simulation of the mathematical model associated to the DC/DC Boost converter−full-bridge Buck inverter system to regulate the voltage output of the DC/DC Boost converter allowing bipolar voltages higher than the input voltage via the full-bridge Buck inverter. To validate the model, the differential flatness property is applied via the flat outputs of the system (energy for the DC/DC Boost converter and the voltage of the full-bridge Buck inverter) considering the complete dynamics, in conjunction with fixed and time-variant trajectory planning. In the simulation results, it is observed that the error signals of the states versus the reference trajectories are acceptable. Regarding the validation of the model, this is performed with open-loop simulations at the circuit level using the SimPowerSystems Toolbox of Matlab-Simulink. The simulation results validate the good performance of the system under study. In this way, the main contribution of this w... [more]

The primary aspiration of this paper is to learn about the effects of economic growth, energy consumption, agriculture and irrigation water consumption and agriculture productivity on environmental pollution in five countries of Central Asia. The data cover the period from 1992 to 2020 by applying panel data models, namely the Panel FMOLS, Panel DOLS and Panel ARDL-PMG approaches. The results indicate that there is a positive long-term impact of economic growth, water productivity, energy consumption and electricity production on CO2 emissions while agriculture value added and trade openness have a negative and statistically significant influence on CO2 emissions in Central Asia. Country specific short-run coefficients from Panel ARDL reveal that energy consumption is the main driver for rise in the level of CO2 emissions in the countries under the study. Indeed, country level analysis generates unique nexus correlation among agriculture, energy and environmental degradation in each co... [more]

In 2021, there was a global energy crisis that affected different parts of the world. In most countries, energy heavily relies on natural gas, including Nigeria, India, and Bangladesh. Several studies have explored the differences in the energy of crude oil and natural gas. Nonetheless, little effort has been made toward exploring the exportation of energy for exchange markets in Nigeria, India, and Bangladesh. This paper primarily aims at comparatively exploring the energy of crude oil and natural gas for exchange markets in the aforementioned countries. The methodology used in this paper is qualitative content analysis (QCA) and a systematical literature review (SLR) which includes various sources such as journals, the core collection of the Web of Science (WOS), oil peer review resources, and library sources. The study systematically mapped out different bibliographic materials whereby the visualization of similarities (VOS) was used to explore exchange markets for energy, crude oil... [more]

This paper presents a method for preparing a pressure sensor that is insensitive to acceleration along with experimental evidence of its efficacy in aerodynamic analysis. A literature review and preliminary studies revealed the undesirable effect of acceleration on sensors that are located on moving elements, as evidenced by deviations from actual pressure values for piezoresistive pressure sensors that are made using MEMS technology. To address this, the authors developed a double-membrane sensor geometry that eliminated this imperfection; a method of implementing two solo pressure sensors as a new geometry-designed sensor was also proposed. Experimental tests of this suggested solution were conducted; these measurements are presented here. The results indicated that this new sensor concept could be used to measure the dynamic pressures of rotating and moving objects in order to obtain measurement results that are more reliable and closer to the true values that are derived from aerod... [more]

Climate changes necessitate measures to reduce greenhouse gas emissions (GHG). The European Union’s climate and energy policy places particular emphasis on the development of renewable energy, considered to be the primary mean in achieving the climate neutrality goal by 2050. Having in mind the aforementioned, the study was conducted to determine time delay in the development of renewable energy sources between the Visegrad Group (V4) countries and Germany, considered the most advanced country in developing renewable energy and having the greatest impact on shaping European Union climate and energy policy. The time delay econometric method was used in four of its variants. The research results show that, despite the existence of support mechanisms, the development of renewable energy sources (RES) in the V4 countries has a high mutual correlation. There is a hight correlation between RES penetration in energy mix and UE goals of the climate and energy policy until 2020. At the same tim... [more]

The concept of sustainable development integrates activities in the economic, environmental and social areas. Energy policy, which is very closely linked to climate protection, is of key importance for achieving the goals of the concept in question. All these elements are connected by the European Green Deal strategy and Agenda 2030. Their implementation requires the evaluation of previous actions undertaken within the framework of sustainable development and the diagnosis of the current state. Therefore, this article presents the results of such research in relation to the key industry connected with this process, which is the energy sector. The research methodology was based on the analysis of 14 indicators that characterize four basic areas (dimensions) related to energy and climate sustainability. These indicators concern energy and climate as well as social and economic issues. This approach makes it possible to comprehensively assess the actions taken so far in the implementation... [more]

Internet of Things (IoT) is a new concept in the information and communication technology studies which indicates that any creature (human, animal, or object) can send and receive data through communication networks, such as the internet or intranet platform. Wireless sensors have limited energy resources due to the use of batteries to supply energy, and since it is usually not possible to replace the batteries of these sensors. In addition, the lifespan of the wireless sensor network is limited and short. Therefore, reducing the energy consumption of sensors in IoT networks for increasing network lifespan is one of the fundamental challenges and issues in these networks. In this paper, a routing protocol is proposed and simulated based on an ant colony optimization algorithm’s performance. The clustering is performed with a routing method based on energy level criteria, collision reduction, distance from the cluster-head to the destination, and neighborhood energy in the proposed meth... [more]