Energy Resources Research Articles

Optimal environmental policy and business cycles: An analysis using an E2-DSGE model

What are the effects of adopting a comprehensive environmental policy that considers, in addition to taxes on emissions, taxes and subsidies in the energy sector? This paper answers that question using a dynamic stochastic general equilibrium model augmented to include environmental issues and an energy sector featuring non-renewable and renewable energy production. The model is used to find the optimal trajectories of the environmental policy instruments and to analyze the dynamic behavior of the model variables in response to productivity shocks. First, we show that tax and subsidy rates are procyclical. Second, we show that having access to alternative sources of (renewable) energy allows households and firms to replace non-renewable (polluting) energy sources with renewable (cleaner) energy sources in response to productivity shocks. Finally, a welfare analysis of different policy alternatives shows that a broad environmental policy is welfare superior to policies that do not include a full set of taxes and subsidies in the energy sector.

Comprehensive characterization of bioplasticizer from the Murraya koenigii leaves: From biomass to biomaterial for polymer composite applications

The world is moving toward sustainable products in almost all fields. As non-renewable resources are used and getting exhausted, the search for renewable, greener, and sustainable alternatives has become the most preferred option currently. Overall, polymer-based materials are used almost in all products for both in industrial and domestic purposes. One of the main additives used during the processing of any polymeric materials is plasticizers (PSs). Most of the PSs are toxic, which is not welcoming one in current situation. Bioplasticizers (BPs) have become a recent research study option focus to overcome this drawback. In this investigation, Murraya koenigii (MK), a native tree, was chosen for the extraction of BPs (MKBP) from its leaves (MKTL) and subjected to various analyses including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV–visible spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The presence of FTIR peaks showed the possibility of PS similarities with peaks at 1396cm−1 and 1214cm−1. XRD confirmed the crystallinity of the MKBP with a crystallinity index (CYI) of 92.4% and the crystallite size of 0.033µm. UV analysis resulted in a maximum peak at 358.41nm. TGA reported the maximum degradation temperature of 377.3 °C. DSC analysis showed a glass transition temperature (Tg) of 68.89 °C. SEM analysis confirmed a high probability of blending with the extracted MKBP as the extract possessed a rough surface. AFM revealed the surface roughness that matched the SEM results.

Exploring the Nexus of Economic Growth, Energy Mix, Services, Trade Openness, and Environmental Quality: Evidence from N11 Countries

Despite considerable research on the connections between economic growth, energy consumption, trade, and environmental sustainability, a notable gap persists in understanding the varying effects of these factors at different levels of resource use. This study seeks to fill this gap by utilizing quantile panel regression analysis to investigate the intricate interactions among these variables in the N11 countries. Our results indicate that economic growth has a negative impact on environmental sustainability, particularly at higher levels of resource consumption. In contrast, the consumption of renewable energy has a positive effect on sustainability, whereas reliance on non-renewable energy and trade openness produces adverse outcomes. These findings highlight the urgent need for policymakers to pursue a balanced approach to economic development that emphasizes environmental sustainability and considers the social implications of the transition.

High-resolution 3D hydrodynamic modeling and comprehensive assessment of tidal current energy resources

As a clean and renewable resource, tidal current holds significant development potential. However, accurately assessing tidal current energy resources has been a persistent challenge. This study proposes a comprehensive assessment method using a small-scale, high-precision, multi-criteria three-dimensional hydrodynamic model to assess resource reserves applied to the Zhairuoshan Waterway. The hydrodynamic model was employed to simulate critical parameters such as tidal level, flow velocity, and flow direction. Multiple statistical indicators were used to evaluate the model's accuracy, showing consistency. The study analysed the flow speed distribution over a complete cycle, revealing an average flow speed of 1.51 m/s, with a maximum speed reaching 3.83 m/s. The generally high flow speeds within the waterway, coupled with the stability of the tidal current, indicate the significant resource potential of the study area. A quantitative analysis of the spatial distribution of tidal current energy was conducted using energy flux density, and the results showed that high energy density areas are widely distributed. Furthermore, the theoretical tidal energy resources of the waterway were calculated, showing that the maximum resource reserves could reach 9.98 MW at the selected cross-sections. Coupled with the analysis of unit-width energy flux, the high-potential areas within the waterway were further identified.

Investigation of the interactions and influencing factors of the Water-Land-Energy-Carbon system in the Yellow River Basin

The survival and advancement of human society are fundamentally dependent on the availability and sustainable management of water, land, and energy resources. The development and utilisation of various energy sources and a considerable number of natural resources lead to carbon emissions. A complex interplay exists between water, land, energy, and carbon, and their correlation lies at the core of the regional “natural-social-economic” system, which is crucial for human existence and advancement. Despite its importance, research on the water-land-energy‑carbon (WLEC) nexus is limited. In this study, we employed an innovative combination of the comprehensive assessment index, coupled coordination degree, panel vector autoregressive, and random forest models to investigate the spatiotemporal evolution, internal dynamic interactions, and external influencing factors of the WLEC system in the Yellow River Basin (YRB) from 2007 to 2021. The findings revealed that the degree of coupled coordination in the WLEC system of the YRB exhibited an overall steady upward trend. The spatial agglomeration effect was continuously enhanced, and regional disparities increased. Complex interaction mechanisms exist within the water, land, energy, and carbon subsystems in the YRB. Population size, land relief, and sunshine are the prevailing factors influencing the degree of coupling coordination in the WLEC. Addressing the trade-off relationship among the subsystems of the WLEC system is a key aspect of optimising its correlation relationship. This study provides a scientific basis and relevant suggestions for achieving the Double-Carbon Goal, promoting ecological protection and high-quality development in the YRB.

Ion-exchange induced multiple effects to promote uranium uptake from nonmarine water by micromotors

As the fundamental resource in nuclear energy, uranium is a sword of two sides, due to its radioactive character that could cause severe impact to the environment and living creatures once released by accident. However, limited by the passive ion transport, the currently available uranium adsorbents still suffer from low adsorption kinetics and capacity. Here, we report a self-driven modular micro-reactor composed of magnetizable ion-exchange resin and adsorbents that can be used to dynamically remove uranium from nonmarine waters. Because of the long-range pH gradient and phoretic flow established by the recyclable ion-exchange resin, the micro-reactor shows a fast uranium adsorption rate and reaches a uranium extraction capacity of 629.3mgg-1 within 10min in 30 ppm uranium solution, as well as good recyclability in repeated use. Numerical simulation result confirms that the phoretic flow and electric field accelerate uranium transport to the adsorbent. Our work provides a new solution for the removal of radioactive uranium with high efficiency.

Energy release and disaster-causing mechanism of ore-pillar combination

Coal and other mineral resources are also commonly found in bauxite mining. The process of bauxite mining is usually affected by retained ore pillars in other strata, which leads to the formation of combinations composed of different strata. Once these combinations become unstable, they can cause serious disasters that threaten production safety. Aiming at the safe mining of co-associated resources in the overlying coal seams of bauxite mines, in this paper, the strength, fracture development, and energy evolution of the coal-rock-aluminum (C-R-A) combination under varying thickness proportions of coal, rock, and aluminum were studied by means of particle flow code (PFC) numerical simulation, SPSS statistical analysis, and other methods. The results indicate that the strength of the combination is significantly negatively correlated with the thickness of the soft coal seam and remarkably positively correlated with the thickness of the hard aluminum layer. Under the same stress conditions, fractures in the combination mainly occur in the coal seam. As the thickness proportion of the coal seam in the overall structure increases, the number of fractures there grows correspondingly. Under a larger thickness proportion of the rock stratum, the combination releases its elastic energy faster after instability, and the fractures develop more intensely. As the thickness proportion of the rock stratum decreases, the elastic energy index (WET) in the C-R-A combination rises, and the burst proneness strengthens. Areas where the thickness proportions of coal, rock, and aluminum lie in the ranges of 30%–60%, 10%–20%, and 30%–60% respectively are considered high-risk zones, and rock burst accidents are most likely to occur when the thickness ratio of coal, rock, and aluminum is 4: 1: 5. These research findings can provide guidance for the safe mining of similar coal and aluminum associated resources.

Analysis of Qatar's electricity landscape: Insights from load profiling, clustering, and policy recommendations

Demand side management (DSM) is an important strategy for promoting sustainable consumption in resource-rich countries with high purchasing power and subsidized tariffs. Global energy and environmental resource consumption have increased rapidly due to advances in production and transportation, leading to inefficient and wasteful use of resources. DSM aims to address these issues by promoting efficiency. To implement appropriate DSM strategies, a greater understanding of consumer behavior is needed. To do so, load profiling and load clustering are two popular methods that can be used. This paper aims to i) summarize the most recent global load profiling and clustering works ii) use official smart meter data to understand key electricity consumption trends in Qatar, such as temperature-demand correlation, weekend vs. weekday, and public holiday consumption patterns, and iii) perform load clustering to propose policies that would help manage the electricity load in Qatar for its green growth. This study provides insights into the electricity consumption trends of various sectors in Qatar, including commercial, government, hospitality, and residential sectors. It was found that among all the sectors there were only two usage periods of the same time. There is naturally a strong correlation between temperature and electricity consumption throughout the sectors. Furthermore, it was observed that the consumption of the sectors is highly similar which leads to multiple sectors being present in the same cluster. Finally, policy changes are proposed based on the results to encourage demand response programs in Qatar.

Enhanced conversion of rosin to polymerized rosin with reusable Brønsted acid deep eutectic solvent

With the depletion of non-renewable resources and the increasingly serious environmental problems, the production of high value-added polymer materials using renewable resources as raw materials had aroused great interest. Deep eutectic solvent (DES)-[ChCl][TfOH]2 (prepared by choline chloride (ChCl) and trifluoromethanesulfonic acid (TfOH)), with suitable acid strength (H0=0.98) and active hydrogen, had been successfully used for enhanced conversion of rosin to polymerized rosin efficiently, under the conditions of rosin =15 g, mDES: mrosin=30 %, T=110℃ and t=9 h, polymerized rosin with high softening point (150.40℃) and low acid value (124.21 mg KOH/g) could be produced efficiently. [ChCl][TfOH]2 required no special treatment then could be reused for 5 times without significant loss of catalytic performance, on this basis, the green synthesis technology of polymerized rosin under DES system was given, not only promoted the further application of polymerized rosin, but also realized the high value-added utilization of renewable resource rosin. In addition, the formation mechanism of DES was systematically explained through DFT calculation, the reaction mechanism of rosin polymerization over [ChCl][TfOH]2 was explored, which could provide theoretical basis for further research.

A resilient biofuel supply chain design based on Paulownia and Jatropha under uncertainty considering the water-energy nexus

The growth in global population, pollution, and energy demand, in addition to dwindling fossil fuel reserves, are driving scientists and industries toward adopting biomass-based products over non-renewable energy sources. Moreover, the decline of water resources and the importance of conserving water have induced governments to start initiatives to control the consumption of water, especially in the agricultural and industrial sectors. Therefore, the water-energy nexus is a significant issue that has drawn the interest of researchers in recent years. A bi-objective two-stage stochastic multi-product optimization model is presented for designing a resilient second-generation biofuel supply chain under uncertainty, considering the water-energy nexus. In this supply chain, biofuel is yielded from inedible plants Paulownia and Jatropha. Various resilience strategies are adopted to cope with potential disruptions to the supply chain, including multi-sourcing, capacity expansion, imports, multiple transportation modes, and lateral transshipment. The objectives of the model are twofold: maximizing profit and minimizing water consumption. This is achieved by making some key decisions including: facility location, managing the flows of raw materials and finished products among networks, determining production volumes, setting inventory levels, allocating land for biomass crop cultivation, planning production and storage capacities, scaling capacity expansions, the number of vehicles to rent or purchase, and optimizing the amounts of raw materials to import and biomass to export. An actual case study is provided to demonstrate the real-world applicability of the approach, while multiple sensitivity analyses are performed on the problem's main parameters. The study concludes by providing valuable managerial insights that focus on the cost savings and profit increases achievable through resilience strategies. The analysis considers different scenarios and explores effective methods for handling disruptions, emphasizing water resource conservation achieved by integrating the water-energy nexus within the biofuel supply chain.

Optimization of grid-connected hybrid renewable energy system for the educational institutes in Pakistan

To foster resilient energy transition systems, the deployment of renewable energy sources is potentially helpful in the acceleration towards sustainable, reliable, and diversified solutions. In this feasibility study, aims to pursuit the best optimal solution for renewable energy resources, integrated into the local university's energy mix, to meet the electrical load demand of 8500 kWhr/day and a peak load of 815 kW. A model of a hybrid grid-connected renewable energy (PV/Biomass/Hydel/Diesel generator/Grid) system was implemented in HOMER software, to obtain the most efficient and cost-effective hybrid energy generation. The outcomes of the simulation seem more viable based on sensitivity analysis, as the cost of energy (COE) for an energy system with a hybrid combination is 0.13.$/kWh, meanwhile energy price with the grid system is 0.18 $/kWh. According to the HOMER analysis, a hybrid grid-connected PV/biomass/hydro system demonstrates both technological feasibility and economic viability, meanwhile it will also save 1575 tons of CO2 per year. Therefore, this proposed hybrid energy system, a step towards sustainable development, can be applied at institutional levels, especially in developing countries.

Experimental and numerical studies on performance investigation of a diesel engine converted to run on LPG

With the growing environmental concerns and depletion of energy resources, considerable efforts are focused on developing ecofriendly and sustainable transportation systems. This includes the conversion of outdated diesel engines into ecofriendly liquefied petroleum gas (LPG) engines. In this study, a Euro-6 diesel engine mounted on a commercial vehicle (mega truck) was converted into a propane LPG engine. The combustion chamber was modified by changing the piston shapes (PSs), compression ratios (CRs), ignition system, throttle body, and injector design to enable operation using propane. The performance of the modified engines with two different PSs, PS1 and PS2, were experimentally investigated. In terms of the power, the engine designed using PS2 demonstrated better performance than PS1 under all operating speeds, except 2600 rpm. Particularly, PS2 outperformed PS1 by more than 10 Nm in the low-speed range of 1000–1600 rpm. Under full load, the PS2-equipped LPG engine achieved the maximum torque and power of 834 Nm at 1600 rpm and 170 kW at 2600 rpm, achieving 106 % and 86 % of the target torque and power, respectively. Additional exhaust gas emission tests were performed using the PS2-equipped LPG engine. The engine performance varied with the application of exhaust-gas recirculation. Moreover, the results of the world-harmonized stationary cycle mode tests confirmed the conformance of the modified LPG engine to all Euro-6 emission standards. Furthermore, simulation-based performance optimization was conducted considering two PSs and four CRs. Based on the simulations, PS1 achieved higher engine performance and lower CO2 and soot emissions, whereas PS2 had lower NO emissions. Additionally, increasing the CR improved the performance and reduced the CO2 and soot emissions for both PSs. These results indicate the possibility of developing LPG engines with performance comparable to diesel engines. In particular, the modified LPG engine proposed in this work may be installed on buses and trucks in the future and is anticipated to replace outdated medium-generator and marine engines.

Numerical investigation of combustion characteristics of hydrogen-enriched low calorific value landfill gas for energy applications

Landfill gas is regarded as a promising renewable energy resource. However, Low calorific value landfill gases with less than 40 vol% CH4 are not well suited for energy applications and therefore disposed by flaring or direct emission to atmosphere causing environmental problems. In the present work, the potential of using hydrogen-enriched low calorific value landfill gas for energy applications has been explored through numerical investigation of combustion characteristics of different blends of fuels. The ignition delay of fuel mixtures decreased with the increase of hydrogen fraction (H2 enrichment from 0 to 50 vol%) at stoichiometric conditions. At high initial pressure conditions, ignition delay showed a weak relationship with the pressure. The laminar burning velocity increased with the increment of hydrogen fraction for the range of equivalence ratios considered (φ = 0.7 – 1.4) and also with the increase of initial temperature. However, the laminar burning velocity decreased significantly with the increasing initial pressure and hydrogen enrichment has insignificant effect at high initial pressures. The sensitivity analysis shows that the main elementary reactions inhibit the laminar burning velocity more with increasing initial pressure. The combustion performance of low calorific value landfill gas with 30 vol% CH4 enriched with 30 vol% hydrogen shows comparable performance to biogas with 60 vol% CH4 for a range of operating conditions. The numerical investigation results show that hydrogen-enriched low calorific value landfill gas could be used for thermal applications with the use of suitably designed combustion systems operating at low initial pressures and relatively high initial temperatures.

Environmental acidification drives inter-organ energy mobilization to enhance reproductive performance in medaka (Oryzias latipes)

Anthropogenically environmental acidification impacts aquatic organisms, including teleosts, the largest group of vertebrates. Despite its significance, how teleosts allocate nutrient and energy among their organs to cope with acidic stress remains unclear. Our integrated analysis of physiological, metabolic, and gene expression data reveals that Japanese medaka (Oryzias latipes) mobilize energy resources among organs in response to acidic conditions. We found that the muscles lost carbohydrates and proteins and the liver accumulates all macronutrients in both sexes. Notably, female-specific energy mobilization between the liver and ovary were triggered by estrogen signaling, resulting in improved oocyte maturation and ovulation. Female produced more offspring under acidic stress. Furthermore, the offspring embryos exhibited smaller diameters and earlier hatching but demonstrated growth rates and acid tolerance. These metabolic changes suggest a trade-off in energy allocation by suppressing basal maintenance (33% decrease in oxygen consumption) and growth (25% decrease in muscle mass) but enhancing energy storage (159% increase in liver mass in males and 127% in females) and reproduction (165% increase in ovary mass). This reallocation may improve medaka fitness and population sustainability in acidic environments. Further investigation into more species is needed to project the survival of aquatic animals in an acidified future.

Plasma sprayed high-entropy alloy coatings with enhanced water splitting activity in alkaline environment

Developing highly efficient electrocatalysts for water splitting is an effective strategy to promote renewable and sustainable energy resources. Multimetal high-entropy alloys (HEAs) have generated considerable attention as promising catalysts because of their unique properties. Herein, the porous HEA coatings have been prepared via the plasma spraying method, which is expected to resolve the above issues. The catalysts can afford a promising catalytic performance through the distinct porous structure. This work results that the CoCrFeNiAlMo catalyst possesses a tiny overpotential (253mV at 50mAcm-2) with minimal Tafel slope (59.75mV dec-1). At the same time, the CoCrFeNiAlMo catalyst also exhibits a relatively small overpotential for hydrogen evolution reaction. As catalysts for overall water splitting, it delivers a cell voltage of 1.74V at 50mAcm-2 and a superior durable for 48h. This research provides an insight for using the multinary HEA coatings as electrocatalysts in energy applications.

Bi-level optimization of novel distribution network with VPP and flexible load cluster

To satisfy the power requirements of modern industrial parks, while also enhancing energy efficiency and system economy, a bi-level optimization model is proposed for a novel distribution network, which incorporates a virtual power plant (VPP) and flexible load cluster. The proposed optimization model for the distribution network layer considers factors such as minimum voltage offset and operating cost. It accounts for uncertainties associated with new energy sources, control of the soft open point (SOP), as well as dispatching of the static var compensator (SVC). A normalized normal constraint (NNC) method is used to obtain Pareto front. The power flow model is converted into a normalized cone programming model utilizing second-order cone relaxation technique. The VPP optimization layer aims to achieve the lowest operational cost and comprehensively considers the complementarity of multiple types of distributed energy resources. The bi-level iterative solution is obtained using the analytical target cascading (ATC) method. Finally, the enhanced IEEE 33-node system example demonstrates that the proposed bi-level optimization model effectively reduces the system’s operating cost, optimizes the power flow distribution, and minimizes network losses.

Pathways to China's Carbon Neutrality and Clean Energy Transition: Evidence from the Three Decades Long Stricter Environmental regulations

This study highlights the ongoing debate surrounding China's slow low-carbon transition despite a rapid shift towards clean energy. However, this debate is crucial for finding pathways to China's pledge to carbon neutrality. Using Auto-Regression Distributed Lag model over the time series data spanning 1990-2020, study attempts to add to the literature by exploring the nexus betwixt environmental regulations, renewable energy transition, and carbon dioxide emissions along with incumbent macroeconomic factors i.e., economic growth and trade. The findings conclude that stringent environmental regulations spur renewable energy transition and combat carbon dioxide emissions. However, energy intensive growth suggests China's priority for development targets ˗ leading to continued increase in fossil fuels despite the remarkable increase in renewable energy resources in country's total energy mix. Moreover, trade remains the crucial component of economic growth but found helping for renewable energy transition in the short-run. The two-way causality between these factors validate the regression results. Whereas the inelastic and insignificant relationship between stringent environmental regulations, renewables, and carbon dioxide emissions in the long run – highlights prospective challenges in terms of efficiency, management, and subsidy-related issues. Thus, the study suggest that trade liberalization helps the country to achieve its carbon abatement goals. However, further market based policy reforms toward stricter environmental regulations are needed for innovation driven efficiency in the energy sector.

Two-stage optimal scheduling for flexibility and resilience tradeoff of PV-battery building via smart grid communication

Energy flexibility and energy resilience are now becoming new key features of building energy systems under the context of climate change and energy transition. During the system operation phase, these two performance indexes might be contradictory and require tradeoff. The main contribution of this study is to propose a two-stage mixed-integer linear programming (MILP) model to optimally tradeoff between flexibility and resilience. Its main idea is to improve the resilience of building energy system with minimum constraints on system flexibility using the outage risk information provided by smart grid. Two new concepts are considered in the proposed method, including self-sufficient requirement and continuous outage probability. The insight is to add additional penalty for the time step in which its battery state of charge (SOC) is far from self-sufficient requirement while the corresponding continuous outage probability is high. To validate our proposed method, a probabilistic outage simulation model is developed using sigmoid function and Markov Chain. Comprehensive numerical studies are conducted to compare the proposed method with traditional economic mode and backup mode under two outage patterns. The results demonstrate that the proposed method only uses 6.7% additional operation cost such that 78.3% of baseload curtailment and 81.1% of user discomfort are reduced. The proposed MILP model can provide practical guideline for the flexibility and resilience tradeoff of distributed energy resources.

Enhancing commercial building resiliency through microgrids with distributed energy sources and battery energy storage systems

Resilience analysis is gaining focus, but no extensive research exists for commercial buildings. This research presents the results of a novel analysis of the resiliency in commercial buildings by examining the relationship between electric microgrids, Distributed Energy Resources (DERs), and Battery Energy Storage Systems (BESS). As energy systems face increasing challenges, including extreme weather events and grid vulnerabilities, integrating microgrids, DERs, and BESS has emerged as a promising solution to strengthen the resilience of commercial buildings. Microgrids can harness renewable energy sources and reduce environmental impacts when integrated with DERs. Most literature studies focus on residential or commercial buildings with peak-valley tariffs and simplified electrical market models. In contrast, this study focuses on BESS’ pivotal role in DER output and ensuring uninterrupted power during grid disruptions and presents an innovative approach to analyzing resilience in commercial building microgrids and an economic optimization of commercial building microgrids with Time of Use tariffs utilizing DERS and BESS. The analysis includes the technical aspects of BESS integration and control strategies that optimize their operation. It also studies the economic and environmental benefits of microgrids, DERs, and BESS, focusing on cost savings, greenhouse gas emission reductions, and grid support services.

CO2 to fuel: Role of polymer electrolytes on efficiency and selectivity

Global primary energy consumption, which heavily depends on fossil fuels, is on track for depletion, with projections suggesting exhaustion by 2100. This trajectory is further compounded by the persistent rise in atmospheric CO2 levels, currently at 420 ppm, which significantly contributes to climate change and its detrimental environmental consequences. To address this urgent challenge, various strategies have been proposed, including CO2 capture and storage, as well as its conversion into usable fuels. Leveraging the abundance of CO2 as a carbon source, coupled with sustainable energy resources such as solar, wind, and thermal energy, holds promise for generating value-added goods while mitigating environmental harm. This review focuses on the electrochemical reduction of CO2, presenting a dual-pronged approach aimed at decreasing atmospheric CO2 levels. The imperative to simultaneously combat declining atmospheric CO2 concentrations and advance cleaner, sustainable energy sources underscores the urgency of this endeavor. Specifically, we highlight the pivotal role of diverse polymer electrolytes, encompassing cation, anion, and bipolar membranes, in facilitating electrochemical CO2 reduction. Exploring the impact of functional groups within these membranes on CO2 reduction reaction provides insights into potential advancements in synthesis of eco-friendly fuel from conversion of CO2.