Rapidly declining costs of renewable energy technologies have made solar and wind the cheapest sources of energy in many parts of the world. This has been seen primarily as enabling the rapid decarbonization of the electricity sector, but low-cost, low-carbon energy can have a great secondary impact by reducing the costs of energy-intensive decarbonization efforts in other areas. In this study, we consider, by way of an exemplary carbon capture and utilization cycle based on mature technologies, the energy requirements of the “industrial carbon cycle”, an emerging paradigm in which industrial CO2 emissions are captured and reprocessed into chemicals and fuels, and we assess the impact of declining renewable energy costs on overall economics of these processes. In our exemplary process, CO2 is captured from a cement production facility via an amine scrubbing process and combined with hydrogen produced by a solar-powered polymer electrolyte membrane, using electrolysis to produce methano... [more]

An autonomous microgrid is often formed by incorporating distributed generators into the distribution system. However, distributed generators have less inertia compared to traditional synchronous generators, and can cause the system frequency to become unstable. Additionally, as more clusters are integrated into the distribution microgrid, frequency instability increases. To resolve frequency instability in the microgrid cluster, this study proposes a supercapacitor control approach. The microgrid consists of several clusters which integrate wind power generators, solar PV, STP, fuel cells, aqua electrolyzers, and diesel generators. Initially, a small signal model is developed to facilitate the control design. A fractional-order supercapacitor controller is augmented with the developed small-signal model to stabilize the frequency of the microgrid. Furthermore, the controller parameters are optimized to guarantee robust controller performance. The proposed fractional-order supercapacit... [more]

A significant portion of the Indian population lives in villages, some of which are located in grid-disconnected remote areas. The supply of electricity to these villages is not feasible or cost-effective, but an autonomous integrated hybrid renewable energy system (IHRES) could be a viable alternative. Hence, this study proposed using available renewable energy resources in the study area to provide electricity and freshwater access for five un-electrified grid-disconnected villages in the Odisha state of India. This study concentrated on three different kinds of battery technologies such as lithium-ion (Li-Ion), nickel-iron (Ni-Fe), and lead-acid (LA) along with a diesel generator to maintain an uninterrupted power supply. Six different configurations with two dispatch strategies such as load following (LF) and cycle charging (CC) were modelled using nine metaheuristic algorithms to achieve an optimally configured IHRES in the MATLAB© environment. Initially, these six configurations... [more]

Ship emissions are one of the main sources of air pollution in port cities. The prosperous maritime trade has brought great harm to the air quality of port cities while promoting the development of the world economy. During the berthing process, ship auxiliary machines emit a large amount of air pollutants, which have a great impact on air quality and public health. Alternative marine fuels are being studied and used frequently to reduce ship emissions. This research was carried out to investigate the gaseous and particles emission characteristics of a marine diesel engine during the application of experimental biodiesel fuels. To study the influence of mixed fuels on engine performance, measurements were made at different engine loads and speeds. Different diesel fuels were tested using various ratios between biodiesel and BD0 (ultra-low sulfur diesel) of 0%, 10%, 30%, 50%, 70%, 90%, and 100%. The results indicated the use of biodiesel has little influence on the combustion performanc... [more]

We aim to examine the nexus between Foreign Direct Investment (FDI), Renewable Energy Consumption (REC), and income inequality across selected High-Income Countries (HIC), Upper Middle-Income Countries (UMIC), Lower Middle-Income Countries (LMIC), and Low-Income Countries (LIC). Given the cross-sectional dependency, slope homogeneity, and stationarity properties, we find that the aforementioned variables across all the regions are cointegrated in the long run (LR). For LR estimation, we use the Cross-Sectional-Autoregressive Distributed Lag (CS-ARDL) approach. For the HIC and the UMIC, an increase in FDI increases REC, which in turn causes income inequality to decrease. In the case of LMIC, an increase in REC causes an increase in FDI and decreases income inequality. However, we could not establish a significant relationship with the LIC. We also provide some useful recommendations, such as increased institutional efficiency and promotion of renewable energy investments through higher... [more]

Large thickness of shales over 180.0 m was developed in the source rocks of the Shahezi and Yingcheng formations in the Lishu Fault Depression. Moreover, the high amount of gas content and the total hydrocarbon value of gas logging in several boreholes illustrate that there is a great potential of shale gas resources in this region. Therefore, an integrated characterization of shales from the lower Cretaceous Shahezi and Yingcheng formations was provided to evaluate shale gas resources potential. The measurement results illustrated that the organic-rich shale samples with kerogen type Ⅱ during high to over thermal maturity had a higher content of brittle minerals (>50%) and clay mineral dominated by illite. The shales had a total porosity of 3.11−4.70%, a permeability of 1.24 × 10−3−1.52 × 10−3 μm2, and possessed pore types including dissolution pores, inter-layer pores of clay minerals, micro-fractures, intra-granular pores, and organic pores, which were dominated by micropores and me... [more]

The structural parameters of five bituminous coals were analyzed by using X-ray diffraction and attenuated total reflection−Fourier transform infrared spectroscopy. The combustion behavior of coal was investigated by using a thermogravimetric analyzer under air conditions. Furthermore, the relationships between combustion parameters and the coal structure were established. The results show that bituminous coals contain crystalline and amorphous carbon. The aromaticity, interlayer spacing, average stacking height, aliphatic chain length, and the hydrocarbon-generating potential varied with the different bituminous coals. The coal samples exhibited similar weight changes during the combustion process, and the combustion parameters increased with increments in heating rate. The maximum combustion rate and activation energy increased with declining interlayer spacing and hydrocarbon-generating potential and increasing aromaticity, average stacking height, and aliphatic chain length. The bi... [more]

Considering the unsafety of the present blasting network used in the blasting mining of coalfield fires, a unidirectional explosive element (named explosive diode) is proposed according to explosive logic element principles. Through theoretical and experimental analysis, the internal structure and mechanism of the unidirectional transmission of the detonation signal were studied. For an explosive diode, the length of the quenching channel was defined to be the key parameter. The explosive diode was implemented in the traditional blasting network, obtaining an explosive logic network. To evaluate the safety and reliability of the explosive diode and explosive logic network, detonation propagation and explosion-proof experiments were conducted in the lab. The optimum length of the quenching channel to obtain unidirectional detonation transmission was established. The results showed that the explosive diode could reliably control the propagation direction of the detonation signal when the... [more]

Higher alcohols can be included as a third component in biodiesel-diesel mixtures to improve fuel properties and reduce emissions. Determining the optimum concentrations of these fuels according to the purpose of engine use is important both environmentally and economically. In this study, eight different concentrations of diesel (D), waste oil derived biodiesel (WOB), and 1-pentanol (P) ternary mixtures were determined by the design of experimental method (DOE). In order to determine the engine performance and exhaust emission parameters of these fuels, they were tested on a diesel engine with a constant load of 6 kW and a constant engine speed of 1800 rpm. Using the test results obtained, a full quadratic mathematical model with a 95% confidence level was created using the Response Surface Method (RSM) to predict five different output parameters (BSFC, BTE, CO, HC, and NOx) according to the fuel mixture ratios. The R2 accuracy values of the outputs were found at the reliability level... [more]

Bicycle-sharing plays an important role in solving the “last mile” problem of Chinese people and promoting the construction of an environment-friendly society. This study assesses the carbon emissions generated in the life cycle of bicycle-sharing, examines the substitution effect of bicycle-sharing, and quantifies the depletion rate of bicycle-sharing in combination with the current rate of electric vehicles in China. The depletion rate of shared bicycles in China is high, roughly 5−15% per year. In addition, we discuss scenarios where the annual growth rate of electric vehicles is 40%, 50%, and 60%. Results show that when electric vehicles’ depletion rate is 5% and the annual growth rate of electric vehicles is 40%, the largest net emission reduction in 2025 is 1.96 million tons. Additionally, when electric vehicles’ depletion rate is 5% and the annual growth rate of electric vehicles is 60%, the smallest net emission reduction totals 1.7 million tons.

In this article, we analyze the energy consumption data of business customers registered by trading companies in Poland. We focus on estimating missing data in hourly series, as forecasts of this frequency are needed to determine the volume of electricity orders on the power exchange or the contract market. Our goal is to identify an appropriate method of imputation missing data for this type of data. Trading companies expect a specific solution, so we use a procedure that allows to choose the imputation method, which will consequently improve the accuracy of forecasting energy consumption. Using this procedure, a statistical analysis of the occurrence of missing values is performed. Then, three techniques for generating missing data are selected (missing data are generated in randomly selected series without missing values). The selected imputation methods are tested and the best method is chosen based on MAE and MAPE errors.

The development of primary frequency regulation (FR) technology has prompted wind power to provide support for active power control systems, and it is critical to accurately assess and predict the wind power FR potential. Therefore, a prediction model for wind power virtual inertia and primary FR potential is proposed. Firstly, the primary FR control mode is divided and the mapping relationship of operating wind speed and FR potential is constructed. Secondly, a hybrid prediction method of singular spectrum analysis (SSA) and Gaussian process regression (GPR) is proposed for predicting the speed of wind. Finally, the wind speed sequence is adopted to calculate the FR potential with various regulation modes in future time. The results show the advantages of the proposed method in the prediction accuracy of wind power FR potential and the ability to characterize the uncertainty information of the prediction results. Accurate modeling and prediction of wind power FR potential can signific... [more]

Although European energy policy supports the reduction of energy consumption, the current economic and political situation in Poland and uncertainty related to the origin of energy sources do not support it. Therefore, the aim of this paper is to identify and assess the factors that affect the energy-saving behaviour of Polish consumers in the process of energy consumption. The research problem concerns the specificity of behaviours that are part of new trends in consumption, such as greening and the ethical dimension of consumption. The research question arises as to what the social responsibility of consumers is in the process of energy consumption. The research problem comes down to the question of factors that determine the behaviour of an individual consumer in the energy market. In order to realise the indicated purpose of the article, a conceptual research model was built and direct research was conducted using the research method, which was an online survey (CAWI). The research... [more]

Among the renewable energy resources, solar thermal is one of the technologies that significantly contribute to energy supply and reduce global greenhouse gas (GHG) emissions. Solar water heating (SWH) contributes a large proportion of the global solar thermal capacity, with 63% installation for domestic hot water (DHW) systems, 28% for large DHW systems, and the remaining 9% for other applications such as swimming pools heating, solar district heating, and space heating. Still, now, there are many challenges and limitations of those SWH technologies. The present work reviews the current challenges faced in the domestic SWH industry globally. The integration of thermal energy storage (TES) systems for better collector’s radiation absorption and overall performance are also highlighted. Many countries worldwide seem to face similar challenges within the SWH technologies and industry. It is proven that these challenges and limitations can hinder the global capacity of solar thermal utili... [more]

Lignocellulosic biomass is included in the group of renewable energy sources. Its calorific value is high, owing to which it can be successfully used in the production of second-generation fuels, e.g., biogas. However, its complex structure makes it necessary to apply a pretreatment in order to increase the biogas output. This study presents the usability of a pulsed electric field in grass silage pretreatment in methane fermentation and compares it with microwave-induced disintegration. The experiment shows that substrate disintegration with a pulsed electric field (PEF) results in an increase in methane output. The productivity of methane from PEF pretreatment silage increased by 20.1% compared to the untreated control. The application of microwave disintegration, with the assumption that the same energy is used for the pretreatment, resulted in a methane output increase of 6% compared to the control. The highest biogas production output in PEF-pretreated samples was 535.57 NL/kg VS,... [more]

The Ordos Basin contains abundant coal resources in the Upper Paleozoic strata. They are shallowly buried or exposed in the periphery of the basin, forming recoverable coal mines and coalbed methane resources. For the deeply buried coal seams of the basin, however, due to complex changes and difficult mining, less attention was paid before. In recent years, with the exploitation of tight gas related to coal source rocks, a large amount of drilling and seismic data has been accumulated in the southeastern Ordos Basin, which makes it possible to study the distribution change and factors controlling Upper Paleozoic coal seams. Delineation of deep coal development and distribution is an important basis for coal, coalbed methane and related tight gas resources in the Upper Paleozoic. We use core, logging and seismic data to analyze the coal geophysics, thickness variation, paleotopography and sedimentary facies in the southeastern Ordos Basin. The lower part of the Shanxi Formation (Fm.) an... [more]

In power system planning, the growth of renewable energy generation leads to several challenges including system reliability due to its intermittency and uncertainty. To quantify the relatively reliable capacity of this generation, capacity credit is usually adopted for long-term power system planning. This paper proposes an evaluation of the capacity credit of renewable energy generation using stochastic models for resource availability. Six renewable energy generation types including wind, solar PV, small hydro, biomass, biogas, and waste were considered. The proposed models are based on the stochastic process using the Wiener process and other probability distribution functions to explain the randomness of the intermittency. Moreover, for solar PV—the generation of which depends on two key random variables, namely irradiance and temperature—a copula function is used to model their joint probabilistic behavior. These proposed models are used to simulate power outputs of renewable ene... [more]

In this work, a discontinuous airfoil fin printed circuit heat exchanger (PCHE) was used as a recuperator in a micro gas turbine system. The effects of the airfoil fin geometry parameters (arc height, maximum arc height position, and airfoil thickness) and the airfoil fin arrangements (horizontal and vertical spacings) on the PCHE channel’s thermo-hydraulic performance were extensively examined by a numerical parametric study. The flow features, local heat transfer coefficient, and wall shear stress were examined in detail to obtain an enhanced heat transfer mechanism for a better PCHE design. The results show that the heat transfer and flow resistance were mainly increased at the airfoil leading edge owing to a flow jet, whereas the airfoil trailing edge had little effect on the thermo-hydraulic performance. The airfoil thickness was the most significant while the arc height and the vertical spacing were moderately significant to the performance. Moreover, only the airfoil thickness h... [more]

The article discusses alternatives to the development of the common electricity market of the Eurasian Economic Union countries. In the study, the authors identified three tasks: to analyze the process of forming a unified energy market for the EAEU countries; to assess the achievability of indicators of “greening” the economy of the EAEU countries according to the adopted Millennium Goals by 2025 and 2030; and to consider the impact of various factors on the development of the common electricity market of the Eurasian Economic Union countries in the conditions of the current economic crisis. The research hypothesis suggests that the energy unification of the countries will not lead to the abandonment of the use of traditional energy resources, but the need to increase the efficiency and environmental friendliness of their use will come into focus, and the active inclusion of the electric power industry in modern global “green” trends based on the development of renewable energy genera... [more]

Photovoltaic plants are helping to reduce CO2 emissions, but the energy performance of photovoltaic systems must remain high throughout their operational life. Supervision and monitoring are mandatory for large photovoltaic plants because failures can cause high power losses due to the large number of photovoltaic modules. Infrared analysis is effective and reliable in detecting anomalies or failures in photovoltaic modules, but it is time-consuming and expensive when the infrared inspection of large photovoltaic plants is manual. Nowadays, the diffusion of unmanned aerial vehicles equipped with infrared cameras can support the fast supervision of photovoltaic plants. Nevertheless, the use of drones is regulated by international and national rules; consequently, it is not always possible to use a drone, or its utilization is limited based on geographic areas and/or authorizations. Moreover, infrared analysis requires additional requirements when done by drone, because the mutual positi... [more]

Particulate mass concentration is a crucial parameter for characterising air quality. The diesel particulate filter (DPF) is the primary technology used to limit vehicle particle emissions, but it needs periodic cleaning, a process called regeneration. This study aims to assess the impact of active DPF regeneration on the performance and emissions of Euro 5 and 6 vehicles. The study examined both carbon dioxide (CO2) and pollutant (nitrogen oxides (NOx) and particle number (PN)) emissions for eight vehicles tested in the laboratory and on the road. Apart from the DPF, a wide range of emission control systems was covered in this experimental campaign, including exhaust gas recirculation (EGR), diesel oxidation catalyst (DOC), lean NOx trap (LNT) and selective catalytic reduction (SCR) catalyst, revealing the different impacts on NOx emissions. The regeneration frequency and duration were also determined and used to calculate the Ki factor, which accounts for the emissions with and witho... [more]

In Poland, there is a high ratio of private transport and unfavorable patterns of daily commuting. These patterns can be changed by introducing comfortable and eco-friendly vehicles, such as e-scooters and e-bikes. At the same time, the development of the e-micromobility-based vehicle sharing services market is developing. The aim of the article is to analyze selected e-scooters available on the Polish market and to identify the most useful vehicles from two opposing perspectives, i.e., the potential customer and owner of the vehicle sharing system. The PROSA GDSS (PROMETHEE for Sustainability Assessment—Group Decision Support System) method and the graphical representation of GAIA (Geometrical Analysis for Interactive Assistance) were used to search for a compromise and balance between the needs of the indicated stakeholders. The results of the methods used were compared with the results of the PROMETHEE GDSS method, which does not take into account the balance between the stakeholder... [more]

Green energy is a crucial component in addressing expanding energy demands and combating climate change, but the possible negative repercussions of these technologies are frequently disregarded. Green energy’s deployment is tied to environmentally sustainable development goals (SDGs). It can only be achieved by scaling up the finance of investment that provides environmental benefits through new financial instruments and new policies, such as green banks, green bonds, community-based green funds, green central banking, etc. In an effort to address the issues with IPAT and ImPACT, this study employed the STIRPAT model approach, which is a proven framework for energy economics analysis. The author gathers yearly data spanning 2002−2018 for six ASEAN member countries with the aim of investigating the relationship between CO2 emissions, green finance, energy efficiency, and the green energy index (GEX). After preliminary tests, the study employed the Westerlund test and Johansen Fisher tes... [more]

This study investigates a prediction model for the cycle injection quantity in a high-pressure common rail injector under a transient thermal boundary. The results show that the transient temperature increase curve calculated by the mathematical model of the common rail injector under adiabatic flow is significantly different from the experimental data. A non-isothermal model of the injector coupled with heat transfer is established, which considers the actual heat transfer phenomenon. The excellent agreement between the new calculation results and the experimental data confirms that the fuel injection process of a common rail injector comprises the coupled phenomena of fuel heating and heat transfer. Based on the established simulation model, it is found that in the continuous injection process of the injector, owing to the thermal effect of injection, the cycle injection quantity decreases gradually with an increase in the injector working time and then stabilizes. Under the conditio... [more]

Practice shows that CO2/N2-ECBM is an effective technology to enhance coalbed methane. However, there are few field tests in which the technology is applied to enhance the gas drainage in underground coal mines, and the effect is uncertain. In this study, firstly, the reasons for the decrease of gas drainage efficiency in the exhaustion period were analyzed based on the theory of fluid mechanics. Secondly, the mechanism of N2 injection to enhance coal seam gas drainage (N2-ECGD) was discussed: with the gradual decrease of gas pressure in the drainage process, coal seam gas enters a low-pressure state, the driving force of flow is insufficient, and the drainage enters the exhaustion period. The nitrogen injection technology has triple effects of “promoting flow”, “increasing permeability” and “replacing”. Thirdly, the numerical simulations of the nitrogen pressure on drainage effect were carried out based on the fully coupled model. The results show that the higher the nitrogen pressure... [more]