Hasil untuk "Energy industries. Energy policy. Fuel trade"

D. Parra, Luis Valverde, F. Pino et al.

Hydrogen technologies can play an important role in decarbonising our energy system in a variety of ways across the energy value chain. It is therefore critical to identify the strategic roles as well as the conditions under which hydrogen energy systems become attractive for the energy transition. In this paper, the authors present a techno-economic review of hydrogen energy systems including power-to-power, power-to-gas, hydrogen refuelling and stationary fuel cells. We focus on their optimal operation as flexible assets and we identify three actions that can foster their uptake beyond technological progress. First, we recommend optimal electricity supply with dedicated control strategies considering that electricity dominates the levelised cost of hydrogen production via electrolysis. Secondly, hydrogen can enable the further integration of traditionally independent sectors, namely electricity, heat and transport while contributing to decarbonise all. This position can also be advantageous for investors who sell heat and fuels as energy efficient products. Lastly, we examine a whole range of revenues from different products and applications which can be combined (i.e. benefit stacking) to match capital and operational expenditures. We discuss these roles in depth and we conclude that policy makers together with technology developers should elaborate smart strategies to reduce cost by scaling production, stimulate standardisation (e.g., similar to the PV industry) as well as develop new market structures and regulatory frameworks which allow hydrogen technologies to deliver multiple low carbon applications and products.

Gunnar Luderer, S. Madeddu, Leon Merfort et al.

Eyup Dogan, M. Madaleno, Dilvin Taşkın et al.

Although a few studies have analyzed the nexus of renewable energy and green finance, the literature lacks the use of renewable energy by sources. The other major failure is that it uses only annual and small data. Therefore, this study investigates the connectedness and spillovers relationship between green finance and five types of renewable energy (biofuels, fuel cell, geothermal, solar, and wind) by applying the novel TVP-VAR method of Balcilar et al. [1] to the daily indexes from July 31, 2014, to Feb 4, 2022. The results show that dynamic connectedness, both total and pairwise, is heterogeneous over time and influenced by economic events. Furthermore, wind is found to be the largest transmitter of shocks to green finance, followed by biofuels, while both fuel cell and geothermal receive the least shocks. The findings suggest that green finance is mostly a net receiver of shocks from renewable energy sources and that wind has been a net receiver of shocks during the COVID-19 pandemic. A high interconnectedness between the indexes highlights the safe-haven property for diversification purposes of green finance. Our results are important for energy policymakers, those responsible for the implementation of environmental policies, individual investors, and portfolio managers, while also shedding light on the achievement of COP26 goals.

M. F. Bashir, Ben-jiang Ma, Muhammad Shahbaz et al.

Abstract This study sheds new light on the ambiguous role of environmental taxes in reducing energy usage and energy intensity from 1994 to 2018. We contribute to the energy economics literature by unveiling the interaction between environmental taxes, energy intensity, and energy consumption in 29 OECD economies. Owing to the recent environmental reforms and focus on SDGs, it is necessary to examine the impact of environmental taxes on energy consumption and energy efficiency function. The empirical results from FMOLS, DOLS, and panel quantile regression reveal that the implementation of environmental tax helps to control overall energy usage and promotes energy efficiency by encouraging policymakers, industries, and residents to promote innovation in environment related technologies. We conclude by arguing that the efforts towards a sustainable environment by reducing energy consumption should adopt innovative policies by ensuring the displacement of non-renewables and improve energy efficiency.

Selen Uygur, Pelin Bolat, Gizem Kayisoglu et al.

The shipping industry is responsible for around 2% of carbon dioxide (CO₂) emissions worldwide. This research explores the interaction of technology change, operational approaches, and policy measures in achieving the target for reducing greenhouse gas (GHG) emissions. A simulation model based on the system dynamics of the maritime transport system has been created in accordance with International Maritime Organization (IMO) policies such as the Energy Efficiency Design Index (EEDI), the Ship Energy Efficiency Management Plan (SEEMP) and the Carbon Intensity Indicator (CII). Suggested actions to reduce the average speed of ships to 15 knots have shown significant reduction of CO₂ emissions in the short term. Further, the complete phase-out of High Fuel Oil (HFO) and the high uptake of Liquefied Natural Gas (LNG), methanol, and ammonia in an aggressive fuel transition scenario significantly lowers emissions by 2050. Market-based instruments such as fuel price mechanisms and carbon taxes are complementary methods that enable emissions reduction by encouraging the transition to cleaner fuels. The report calls for the harmonization of policies for the long-term sustainability of shipping. Future studies can expand the model by incorporating economy-related factors such as carbon prices and emissions trading mechanisms to help the industry achieve its 2050 net-zero target.

Lovepreet Kaur, Jayant Singh, Alaknanda Ashok et al.

Alternative renewable fuels are the need of the hour due to limited petroleum fuel sources and environmental degradation caused by emissions. This study aims to evaluate the feasibility of utilizing cattle dung bio-oil (CDBO) microemulsions as an alternative fuel in compression ignition engines by investigating their production, stability, performance, combustion, and emission characteristics. CDBO was produced through fast pyrolysis under optimized conditions and blended with high-speed diesel (HSD) using castor oil methyl ester as an additive to prepare stable microemulsions containing 5–20% bio-oil by volume. The experimental objectives included characterization of the bio-oil, development of microemulsions, and assessment of their influence on engine performance, combustion parameters, and emission profiles. The engine testing was conducted on a single-cylinder, 4-stroke, water-cooled, direct-injection diesel engine (Kirloskar AVI, 5 hp/3.73 kW) coupled with an eddy current dynamometer. The setup was equipped with sensors and transducers to measure all required parameters. The findings indicated that the microemulsions having 20% bio-oil exhibited higher brake specific energy consumption (BSEC) (16.4%) and lower brake thermal efficiency (13.2%) than that of diesel, while the brake power remained almost the same at full loads. The microemulsion fuels produced significantly lower carbon monoxide (27%) and hydrocarbon emissions (41.5%), and the temperature of exhaust gas was higher (10.4%). At high loads, the microemulsions generated 23.5% lower smoke emissions than HSD. The ignition delay was the same as for diesel operation at higher loads, while the cylinder peak pressure was 6.4% higher than that of diesel.

Eyal Sasson, József Kádár, Tali Zohar et al.

Abstract Energy storage technologies (ESTs) play an important role in integrated, decentralized renewable energy systems. However, the lack of public acceptance and awareness of ESTs can significantly delay or block the implementation of renewable energy projects. This study aims to identify the societal and legislative barriers to implementing ESTs using the southern Arava region in Israel as a case study. This research involves semistructured interviews with decision-makers, such as government officials, stakeholders, and business owners. Additionally, an online survey is conducted to understand the knowledge and awareness of residents of this region about energy transition and the various types of ESTs. The findings indicate that while 83% of respondents supported EST installations outside their residential areas or workplaces, 27% opposed having them within their residential areas. Approximately 11% of respondents stated that ESTs negatively impact the landscape, and approximately 6% expressed concern about the health-related hazards caused by local energy storage facilities. Our findings not only highlight that decision-makers consider the economic benefits to the local community as the main driving factor for public acceptance of such installations but also show that ESTs are a critical step toward achieving energy independence and increasing urban resilience to cope with unexpected crises.

Samson Onoriode Okpo, Mark Chijioke Ibeh

Biodiesel has attracted worldwide interest as an alternative renewable fuel source to fossil fuels, but its industrial applications are limited to catalytic inefficiencies, high costs of production, and environmental trade-offs. This review summarizes the gains in catalyst development and process integration and aims to determine new trends, compare performance of different classes of catalysts, and provide a roadmap to sustainable adoption in industry. Scopus, Web of Science, and ScienceDirect were utilized to conduct a systematic review of peer-reviewed studies published between 2015 and 2025, covering both the historical milestones and the latest innovations. It is found that there is a strong transition between traditional homogeneous and heterogeneous heterogeneous systems and sophisticated nanocatalysts, bifunctional systems, MOFs, COFs, and biochar systems, which present varying benefits to activity, selectivity, and recyclability but remain at a disadvantage due to deactivation, feedstock effects, and bottlenecks in mass transfer. Ultrasound-assisted systems and microreactors have also facilitated intensifying reactions, whereas artificial intelligence (AI) and machine learning (ML) have made it possible to predictatively model catalyst performance, feedstock oscillations, and yield optimization. Regardless of these developments, high feedstock prices, techno-economic uncertainties, and life-cycle environmental issues still present a critical obstacle. In the future, the integration of hybrid catalysts, circular biorefinery, digital approaches, and facilitating policy frameworks will prove pivotal towards scaling the biodiesel production. Together, these avenues will make biodiesel not just a renewable transportation resource but also a key pillar of the circular bioeconomy and the global energy transition towards low-carbon.

Min Li, Michael Yao-Ping Peng, Raima Nazar et al.

A comprehensive analytical study to assess the performance level of industrial functions in the environment has become necessary at the present time. According to existing research, the COVID-19 pandemic resulted in a significant reduction in carbon emissions in 2020. Policymakers are focusing on the discrepancies and negative environmental effect caused by various industries during their routine operations. This study aims to estimate the performance level of energy in the context of the environment of the countries that are members of the European Union This evaluation is performed through a data envelopment analysis (DEA) model, through which we have applied a non-proportional adjustment, taking into account the input of energy and its undesirable output. The DEA model allows dynamic assessment of sources in the field of measuring energy efficiency and its environmental effects. The score of measurement of efficiency lies between zero and one, which means China and Russia are awarded this score of one (1), which shows the highest level of efficiency in clean energy, while Bangladesh (0.19), Uzbekistan (0.09), Mongolia and Cambodia (0.06), and Kyrgyzstan (0.04) are at the lowest level of performance in clean energy. The results of the study showed that clean energy efficiency levels increased in all countries over the study period. The emission level of greenhouse gases in the first world countries was found to be better in the context of improvement in performance enhancement in the sector of the energy mix. Evasion score is measured as 365 kt of CO2. This score for NO2 is 280 kt and for SO2 is 82 kt, whereas it is 23 kt (0.24 kg/cap) of particulate hazardous matter. The higher performance level of energy yields a negative relationship with emissions of gases, with a significant number of 12% for NO2 in 2000, as compared to 13% for SO2 and 14% for PM2.5. Whereas PM10 has the highest concentration (18%). Public policymakers may enhance the facilitation system for better free trade and a result-oriented corporate environment to enhance the performance level of energy in the electric sector.

Lixian Fan, Hao Yang, Xinfang Zhang

Compared to air, rail, and road transport, shipping is a more energy-efficient and environmentally friendly way to transport goods over a long distance. However, the unprecedented growth of global seaborne trade has had a significant impact on the environment. The process of shipping transportation, through exhaust gas, wastewater discharge, fuel leakage, etc., has caused very serious environmental pollution. In response to this issue, the International Maritime Organization introduced the International Convention for the Prevention of Pollution from Ships (MARPOL) Convention to regulate the discharge of pollution from ships. Given that there are few studies discussing policy effectiveness, this study comprehensively considers and reviews the implementation effectiveness of all annexed policies under the MARPOL Convention. After discussing the differences between these policies based on the implementation conditions, requirements, strictness, and scope of adoption, the empirical analysis method of time-varying differences-in-differences model is adopted to analyze the policy effectiveness of each annex. It further puts forward suggestions and references for the formulation of effective maritime policies in the future that should be targeted, comprehensive, contingency-based, and proactive. This will help design or revise policies in the shipping industry, thereby promoting the early achievement of shipping emission reduction targets and contributing to the sustainability of the shipping industry.

Ning Zhou, Bowen Shang, Jinshuai Zhang et al.

Expanding photovoltaic (PV) resources in rural-grid areas is an essential means to augment the share of solar energy in the energy landscape, aligning with the “carbon peaking and carbon neutrality” objectives. However, rural power grids often lack digitalization; thus, the load distribution within these areas is not fully known. This hinders the calculation of the available PV capacity and deduction of node voltages. This study proposes a load-distribution modeling approach based on remote-sensing image recognition in pursuit of a scientific framework for developing distributed PV resources in rural grid areas. First, houses in remote-sensing images are accurately recognized using deep-learning techniques based on the YOLOv5 model. The distribution of the houses is then used to estimate the load distribution in the grid area. Next, equally spaced and clustered distribution models are used to adaptively determine the location of the nodes and load power in the distribution lines. Finally, by calculating the connectivity matrix of the nodes, a minimum spanning tree is extracted, the topology of the network is constructed, and the node parameters of the load-distribution model are calculated. The proposed scheme is implemented in a software package and its efficacy is demonstrated by analyzing typical remote-sensing images of rural grid areas. The results underscore the ability of the proposed approach to effectively discern the distribution-line structure and compute the node parameters, thereby offering vital support for determining PV access capability.

Rudai Yan, Yan Xu

Abstract This paper presents a deep reinforcement learning based data‐driven solution to the microgrid bidding in the electricity market considering offers for the reserve market. The framework, based on the Markov decision process, models the microgrid's participation in the electricity market at different stages, including bidding, market‐clearing, and reserve activation. The problem is split into two stages: day‐ahead submission and real‐time market period, and the proposed method mainly focus on the first stage. The state information from state‐space models of distributed energy resources serves as input for the policy network. A deep deterministic policy gradient is employed to train the network and produce a deterministic bidding strategy. The second stage can then adjust this strategy based on the results from the first stage. The method is validated with real‐world microgrid systems and data from the Singapore spot market.

Rizwana Yasmeen, Gang Hao, Yusen Ye et al.

Climate change poses a pressing and urgent peril to the overall welfare of the planet, with far-reaching implications for human livelihoods. The aim of this research is to explore the influence of environmental technologies, environmental taxes, and FDI in B&R economies on increasing renewable energy use and lowering ecological footprints. It also strives to examine how the quality of governance in B&R nations affects the promotion of these environmental initiatives. This study presents interesting results by employing a unique Method of Moments Quantile Regression approach for the period from 1996 to 2018. This highlights the government's ability to effectively utilize environmental technologies and implement a streamlined taxation system, bolstering the renewable energy industry and addressing environmental concerns. Moreover, the study highlights the beneficial impact of governmental initiatives in attracting environmentally friendly investments in the renewable energy sector. However, significant reforms are necessary to execute taxation policies efficiently and offer strong backing for technological progress in the renewable energy industry, aiming to decrease carbon emissions substantially. The findings suggest a need for policy recommendations to increase renewable energy consumption and rectify ecological imbalances, with a focus on matching government goals and reforms associated with environmental taxation and technology.

种芝艺, 李燕雷, 程述一 et al.

针对使用广泛的500 kV架空输电线路，分别研究了在轻、中、重冰区，由断线及不均匀覆冰引起的导线张力对输电杆塔安全性和经济性的影响。研究表明：导线张力增加0～20%，若保持杆塔杆件规格不变，悬垂塔的超限杆件比例为0～51%，耐张塔的超限杆件比例为0～4%；若增大杆塔杆件规格以保证安全，悬垂塔的塔重增加0～28%，耐张塔的塔重增加0～5%；覆冰越厚，由断线引起的导线张力对杆塔影响越小，由不均匀覆冰引起的导线张力对杆塔影响越大；导线张力主要影响悬垂塔横担上、下平面交叉材、塔身主斜材等杆塔杆件。因此，对重要输电线路和输电线路重要区段，推荐重点加强悬垂塔的防串倒及抗冰能力。研究结论对工程实践具有一定的指导意义。

M. Norton, A. Báldi, V. Buda et al.

In recent years, the production of pellets derived from forestry biomass to replace coal for electricity generation has been increasing, with over 10 million tonnes traded internationally—primarily between United States and Europe but with an increasing trend to Asia. Critical to this trade is the classification of woody biomass as ‘renewable energy’ and thus eligible for public subsidies. However, much scientific study on the net effect of this trend suggests that it is having the opposite effect to that expected of renewable energy, by increasing atmospheric levels of carbon dioxide for substantial periods of time. This review, based on recent work by Europe's Academies of Science, finds that current policies are failing to recognize that removing forest carbon stocks for bioenergy leads to an initial increase in emissions. Moreover, the periods during which atmospheric CO2 levels are raised before forest regrowth can reabsorb the excess emissions are incompatible with the urgency of reducing emissions to comply with the objectives enshrined in the Paris Agreement. We consider how current policy might be reformed to reduce negative impacts on climate and argue for a more realistic science‐based assessment of the potential of forest bioenergy in substituting for fossil fuels. The length of time atmospheric concentrations of CO2 increase is highly dependent on the feedstocks and we argue for regulations to explicitly require these to be sources with short payback periods. Furthermore, we describe the current United Nations Framework Convention on Climate Change accounting rules which allow imported biomass to be treated as zero emissions at the point of combustion and urge their revision to remove the risk of these providing incentives to import biomass with negative climate impacts. Reforms such as these would allow the industry to evolve to methods and scales which are more compatible with the basic purpose for which it was designed.

Dennis Lottis, Anna Kallert

Abstract An important measure for decarbonising the heating sector is the transformation of existing district heating (DH) systems into low-emission heating grids based on renewable heat sources. The test facility for DH applications “District LAB (D-LAB)” is currently being set up in order to support the transition by enabling the experimental investigation of various transformation measures. It consists mainly of a Flexible Heating Grid (FHG), which connects several decentralised Hardware-in-the-Loop (HIL) and is fed by a central generation plant. The HIL units in the FHG should be able to map almost any heat producer or consumer, so that a wide range of investigation scenarios is possible. In order to fulfil this requirement, the Heat Exchanger (HEx) that connects the HIL units with the FHG must extract or feed a defined heat flow from the grid and at the same time ensure a defined secondary-side outlet temperature. In a literature research conducted to the best of our knowledge, it turned out that in all technical applications only one outlet temperature is controlled. Therefore a suitable control concept had to be developed. This has been done by extensive simulative investigations, which are presented in this paper. Two control concepts, (I) “decoupled PID controller”, (II) “Characteristic Field (CF)-Based Control”, were self-developed and compared with each other. In order to represent a large spectrum of possible operating conditions with regard to the transformation of DH systems, 48 investigation scenarios based on target value steps were defined and used for the comparison. Subsequently, the average performance using the Root Mean Square Error (RMSE) as well as the time dependant step responses were examined. It turned out that, the CF-based concept appears to be more suitable for use in the D-LAB. It is conceivable that these results can also be transferred to other test facilities in which both, the heat flow and one outlet temperature need to be controlled.

Barbara Breitschopf, Abigail Alexander-Haw

Renewable electricity procurement auctions (RE auctions) have received much attention for their potential efficiency in reducing the cost of support levels associated with renewable electricity (RE). However, very little attention has been paid to their impact on financing costs. This is problematic as financing costs are central for investors when deciding whether to invest in renewable technologies, and can thus be critical for effective RE deployment. We applied a multi-level risk perspective that comprises country specific, renewable sector related and project related risks. This risk-based approach was used to identify the effect of RE auction implementation on financing costs whilst including relevant further risks. Using a 2-level cross classified multilevel model, it was demonstrated that, contrary to politician's fears, the implementation of auctions does not increase financing costs. In addition, technology type and the state of development of the finance sector in the specific country were revealed as having a very significant impact on the cost of capital. Our findings indicate that in order to promote the deployment of RE technologies, policy makers should not focus on whether or not to deploy auctions, but on general financial conditions, the type of remuneration scheme, and risk mitigation in general.

Moushumi Patowary, Hassan Haes Alhelou, Gayadhar Panda

Abstract A relative assessment on conventional and adaptive current controllers used in reduced sensor‐maximum power point tracking (MPPT) based photovoltaic (PV)‐grid tied inverter systems for the improvement of system power quality is suggested. The steady‐state and transients errors produced in the conventional PI and proportional resonant controllers, which are used to generate the references, can be fixed by using an intelligent ADALINE‐LMS adaptive controller; moreover, it helps in reducing the %THD (total harmonic distortion) level measured at different power zones. Also, to track the maximum PV power, which is further integrated to DC‐bus, a reduced sensor‐based technology is added into the circuit that sidesteps the problem of tracking local MPP instead of global MPP and the drawbacks of using current sensors. The use of a reduced sensor‐based MPPT controller confirms extraction of maximum PV power and it guarantees a constant DC‐link voltage under all the possible test conditions. The overall control architectures and system performances, which are tested under different system dynamics, are validated through MATLAB/Simulink as well as experimental findings obtained using the dSPACE RTI 1202 interfacing kit. These experimental results confirm that the adaptive control technique used in reduced sensor‐MPPT based PV‐grid tied inverter systems performs unbeatably with balanced load and grid voltages, less harmonics, quick response time etc. under the operation of linear, non‐linear and transient loads, whereas, conventional controllers are best only for the linear loads.

Tingquan Tian, Haiou Wang, Kun Luo et al.

In the present work, direct numerical simulation data of a laboratory-scale high Karlovitz number (Ka) jet flame with a strong mean shear and a high Ka freely propagating planar flame without a mean shear were analyzed to explore the influence of flame orientation and mean shear on flame stretch in highly turbulent flames. Three flame fronts, i.e. the leading, in-plane and trailing front, were identified for the jet flame. The leading and trailing front is defined as the flame normal being facing the downstream and upstream regions, respectively, while the flame normal of the in-plane front is near the cross-stream plane. It was found that the flame stretch is positive in the leading front, and is negative in the trailing front of the jet flame. As for the planar flame, the statistics of the flame stretch are similar in various flame fronts. The components of the flame stretch are analyzed. The normal vector of the leading front is aligned with the most compressive strain rate in the jet flame, resulting in a large tangential strain rate, while the tangential strain rate of the trailing front is significantly lower. In contrast, the alignment characteristics and the strain rates of the planar flame are not sensitive to the flame orientation. The value of the stretch due to curved propagating flame front is large and negative in the trailing front of the jet flame due to the negative correlation between the displacement velocity and curvature, which is weak in the leading and in-plane front. The correlation between the displacement velocity and curvature is, however, similar in various fronts of the planar flame. Overall, it is suggested that the effects of flame orientation and mean shear should be accounted for in understanding turbulence-flame interactions in practical combustion devices.

Hanif Auwal Ibrahim, Michael Kweneojo Ayomoh

The ever-increasing demand for electricity, as well as its impact on the environment, necessitates expanding the power generation mix of Nigeria by utilizing sustainable energy sources. Power generation planning that is sustainable and efficient must meet various objectives, many of which conflict with one another. Using multi-objective optimization, a model for Nigeria's power supply architecture was developed to integrate indigenous energy sources for a sustainable power generation mix. The model has three conflicting objectives: reducing power generating costs, reducing CO2 emissions, and increasing jobs. Hybrid Structural Interaction Matrix was utilized to compute the weights of the three objectives for the multi-objective model to be modified into a single-objective model. According to the simulations, Nigeria could address its power supply deficit by generating up to 2,100 TWh of power by 2050. Over the projected period, large hydropower plants and solar PV will be the leading option for Nigeria's power generation mix. Furthermore, power generation from solar thermal, incinerator, nuclear, gas plant, combined plant, and diesel engine will all be part of the power supply mix by 2050. In terms of jobs expected to be created, about 2.05 million jobs will be added by 2050 from the construction and operation of power generation plants. CO2 emissions will attain 266 MtCO2 by 2050. The cost of power generation will decline from a maximum of 36 billion US$ in 2030 to 27.1 billion US$ in 2050. Findings conclude that Nigeria can meet its power supply obligations by harnessing indigenous energy sources into an optimal power supply mix.