The increasing integration of renewable energy sources has caused spatially and temporally uneven inertia distribution in power systems. This paper proposes a regional inertia estimation and virtual inertia configuration method using dynamic mode decomposition (DMD). A regional equivalent inertia model is established based on inertia estimation theory for renewable-penetrated power systems. The power system is partitioned via spectral clustering, and frequency measurement nodes are selected according to Pearson correlation coefficients of regional nodes. Regional inertia is then estimated through the DMD method. Critical regional inertia requirements are calculated based on frequency security constraints to configure virtual inertia for renewable energy and energy storage systems. An improved IEEE 10-machine 39-node model with wind-storage systems is implemented in PSCAD for validation. Simulation results demonstrate that the proposed method achieves regional inertia estimation with errors below 5%. The online virtual inertia configuration strategy for wind turbines and energy storage systems effectively prevents frequency violations and enhances frequency security and stability.
Siddhi Mehta, Michael Perez‐Tello, Abhishek Kumar
et al.
ABSTRACT With increasing demand for renewable energy sources, efforts have been made to develop dye‐sensitized solar cells (DSSCs) that utilize renewable green materials with cost‐effective fabrication procedures. In this paper, we report a green, low‐cost carbon(Cx)/liginin/α‐Fe2O3 (LFCx) composite photoanode (PA) with tunable electrochemical performance to improve efficiency of DSSC. The DSSC was assembled using an LFCx thin‐film photoanode on an indium‐doped tin oxide (ITO) glass, activated carbon counter‐electrode. Characterization was conducted using scanning electron microscopy, UV–Vis spectroscopy, interferometry, and photovoltaic performance testing. The assembled DSSC exhibits a bandgap of 3.04 eV, with a short‐circuit current density (Jsc) of 10.21 mA cm−2 and an overall efficiency of 3.46% at 1 sun illumination. The power conversion efficiency reported in this research is 47.5% greater than the highest reported value to date.
Materials of engineering and construction. Mechanics of materials
The power fluctuations of renewable energy sources （RES） adversely affect their frequency regulation performance when participating in active frequency response （AFR）， while current assessment methods for RES frequency regulation capability remain inadequate. To address these challenges， this paper proposes an optimized AFR approach for RES based on distributed model predictive control （DMPC）. The proposed method employs Tube-based model predictive control （MPC） for RES units within fault-affected areas， while utilizing robust control barrier functions （RCBF） to constrain the control parameters of RES in non-fault zones. This integrated approach establishes an improved distributed MPC framework that ensures both conventional units and RES units can effectively perform AFR amidst renewable power fluctuations. Furthermore， the method determines the optimal load-shedding rate for RES to maintain sufficient power reserve and frequency regulation capacity， thereby formulating an executable AFR strategy. This approach enables practical implementation of RES-based AFR control. Simulation studies on an interconnected power system with high renewable penetration demonstrate that the proposed method significantly enhances the AFR capability of renewable energy sources.
The Carbon Border Adjustment Mechanism (CBAM) aims to mitigate carbon leakage and foster global decarbonisation by introducing carbon pricing on imported carbon-intensive goods entering the EU. This paper evaluates CBAM’s impact on the interconnected electricity market of Croatia and Bosnia and Herzegovina, analysing how variable renewable energy sources (VRES) deployment and CBAM compliance reshape energy trade, emissions, and system flexibility. Using the Dispa-SET model, a unit commitment and power dispatch tool for multi-zonal systems with high renewables integration, the study examines electricity flows, fossil fuel dependency, and decarbonisation trajectories across three scenarios: NECP, representing planned technologies; LRES, reflecting low renewables integration; and HRES, with high renewable deployment. The results show that accelerated VRES deployment reduces fossil fuel dependency, with CO2 intensity in Bosnia and Herzegovina dropping to 0.85 gCO2/kWh by 2035 under the HRES scenario. Electricity exports from Bosnia and Herzegovina to Croatia decline from 3.41 TWh in 2025 to 1.39 TWh by 2035 under the NECP scenario but stabilise at 2.35 TWh in the HRES scenario. Curtailment in Bosnia and Herzegovina rises to 2.73 TWh/year by 2035, or 24.2 % of VRES generation, highlighting the challenges of managing high renewable penetration. The interplay between declining coal power operations, reduced emissions, and shifting electricity exports underscores the complexities of aligning regional energy systems with EU decarbonisation goals while ensuring energy security.
Taking the Ordos Basin as an example, this paper proposed that the construction of an energy super basin should follow the principle of “more energy, less carbon, and better energy structure”. The modeling workflow of energy super basin was built. Based on the resources/reserves, development status and infrastructures of the Ordos Basin, the development potential of the basin was evaluated, the uncertainties in the construction of energy super basin were analyzed, and the future vision and realization path of the Ordos Energy Super Basin were recommended. This study demonstrates that the Ordos Basin has the advantages of abundant energy sources, perfect infrastructures, well-matched carbon source and sink, small population density, and proximity to the energy consumption areas. These characteristics ensure that the Ordos Basin is a good candidate of the energy super basin. It is expected that the energy supply of the Ordos Basin in 2050 will reach 23×108 t of standard coal, and the proportion of fossil fuels in energy supply will decrease to 41%. The carbon emissions will decrease by 20×108 t compared to the emissions in 2023. The future construction of the basin should focus on the generation and storage of renewable energy, and technological breakthroughs for the carbon capture, utilization and storage.
In today’s power systems operation, the dual challenge of optimizing economic load distribution while minimizing power plant emissions is pivotal. This challenge is accentuated by the pressing environmental concerns and the finite nature of fossil fuel reserves. In this context, renewable energy sources, notably wind power, have emerged as indispensable alternatives due to their cost-effectiveness and environmental compatibility. However, the inherent variability of wind velocity introduces uncertainty into power output, necessitating innovative approaches to address this complexity. To tackle this issue, we propose a scenario-based probabilistic approach that dynamically considers the slope rate of power output. By leveraging the Blue Whale multi-objective algorithm and employing the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) criterion, we identify significant solutions from the Pareto set across a spectrum of scenarios. Our method is rigorously evaluated across various systems and operational contexts, revealing its superiority over alternative algorithms. Specifically, our approach achieves lower objective function values, reduced standard deviation, and superior overall performance. These findings underscore the critical importance of efficient power system management in balancing environmental sustainability and economic viability. By embracing innovative methodologies, we can navigate the evolving energy landscape and contribute towards a more sustainable future.
Production of electric energy or power. Powerplants. Central stations
Electrifying the residential sector is critical for national climate change adaptation and mitigation strategies, but increases in electricity demand could drive-up emissions from the power sector. However, the emissions associated with electricity consumption can vary depending on the timing of the demand, especially on grids with high penetrations of variable renewable energy. In this study, we analyze smart meter data from 2019 for over 100 000 homes in Southern California and use hourly average emissions factors from the California Independent System Operator, a high-solar grid, to analyze household CO _2 emissions across spatial, temporal, and demographic variables. We calculate two metrics, the annual household electricity-associated emissions (annual-HEE), and the household average emissions factor (HAEF). These metrics help to identify appropriate strategies to reduce electricity-associated emissions (i.e. reducing demand vs leveraging demand-side flexibility) which requires consideration of the magnitude and timing of demand. We also isolate the portion of emissions caused by AC, a flexible load, to illustrate how a load with significant variation between customers results in a large range of emissions outcomes. We then evaluate the distribution of annual-HEE and HAEF across households and census tracts and use a multi-variable regression analysis to identify the characteristics of users and patterns of consumption that cause disproportionate annual-HEE. We find that in 2019 the top 20% of households, ranked by annual-HEE, were responsible for more emissions than the bottom 60%. We also find the most emissions-intense households have an HAEF that is 1.7 times higher than the least emissions-intense households, and that this spread increases for the AC load. In this analysis, we focus on Southern California, a demographically and climatically diverse region, but as smart meter records become more accessible, the methods and frameworks can be applied to other regions and grids to better understand the emissions associated with residential electricity consumption.
Renewable energy sources, Energy industries. Energy policy. Fuel trade
Ammar Alkhalidi, Mohamad K. Khawaja, Mohammad Ali Abdelkareem
et al.
This study presents a set of guidelines for starting a water energy database (WEB). Implementing such a database helps decision-makers select appropriate energy efficiency and renewable energy projects for the water sector. The proposed guidelines encompass various aspects of the database structure including static data, dynamics data, water production, energy consumption, and WEB. Data accuracy is vital for this Database; therefore, a coding system for water utilities is proposed to avoid confusion. Desktop validation and validation through site visits were performed to ensure data accuracy. Recommendations for site visits and data collection procedure were proposed to guarantee the best results. The study proposed techniques that were successfully implemented and tested in the Jordanian water sector.
Boujlel Islem, Logerais Pierre-Olivier, Ben Younes Rached
et al.
Photovoltaic (PV) modules in service undergo more or less severe degradation depending on their operating environments, ages and technologies. In this work, we investigated the coupled influence of the climatic conditions of operation and of the degree of deterioration of a PV module on its energy production. We considered four silicon PV modules characterized in standard test conditions. The PV conversion is modeled by a single diode model taking into account the presence of a fault. Matlab/Simulink software was used to calculate the energy supplied at a constant load for the PV module with and without defects. The ratio between the energy produced with fault and without fault allowed to quantify the percentage of loss. This loss was plotted according to the degrees of degradation of the short-circuit current Isc, the open-circuit voltage Voc, the series resistance Rs and the shunt resistance Rsh. It is shown that when irradiance is held constant, the energy loss is lower with increasing temperature for Isc and Rsh, and vice versa for Voc and Rs. While the temperature is kept constant, the energy loss is lower when the irradiance increases for Isc and Rsh, and inversely for Voc and Rs. A multicriteria analysis enabled to determine the most robust module among the four ones.
Brian G. Sanderson, Richard H. Karsten, Daniel J. Hasselman
An area has been designated for demonstrating the utility of marine hydrokinetic turbines in Minas Passage, Bay of Fundy. Marine renewable energy may be useful for the transition from carbon-based energy sources, but there is concern for the safety of fish that might encounter turbines. Acoustic receivers that detect signals from acoustically tagged fish that pass through the tidal demonstration area and the detection efficiency of tag signals might be used to estimate the likelihood of fish encountering marine hydrokinetic turbines. The method requires that tagged fish passing through the development area will be reliably detected by a receiver array. The present research tests the reliability with which passing tags are detected by suspending tags beneath GPS-tracked drifters. Drifters carrying high residency Innovasea tags that transmitted every 2 s were usually detected by the receiver array even in fast currents during spring tides but pulse-position modulation tags were inadequate. Sometimes very few high residency tag signals were detected when fast tidal currents swept a drifter through the receiver array, so increasing the transmission interval degrades performance at the tidal energy development area. High residency tags suspended close to the sea surface were slightly less likely to be detected if they passed by during calm conditions. Previously measured detection efficiencies were found to slightly overestimate the chances of a high residency tag carried by a drifter being detected as it passed by a receiver. This works elucidates the effectiveness with which acoustically tagged fish are detected in fast, highly turbulent tidal currents and informs the application of detection efficiency measurements to calculate the probability that fish encounter a marine hydrokinetic turbine.
Dimitrios Drosos, Grigorios L. Kyriakopoulos, Stamatios Ntanos
et al.
Global economic growth is accompanied by increased energy demand, thus conventional fuels such as coal, oil and gas, which are the primary energy sources, are gradually being depleted. At the same time, the combustion of conventional fuel for energy production causes serious adverse effects on the environment and contributes to climate change due to the emitted greenhouse gases. For the above reasons, most of the developed and developing countries especially during the last decades, have introduced various incentives for the greater penetration of renewable energy sources (RES) in all sectors of the economy. Concerning the building sector, several measures have been adopted, including the promotion of energy efficiency and energy saving. A significant proportion of the building stock are the school buildings where students and teachers spend a significant proportion of their daily time. Teachers' attitudes and views, especially the school unit managers concerning the use of RES in schools, are important in the effort to rationalize and control energy use. This study was conducted through a structured questionnaire applied to a sample of 510 school managers in Greece's primary and secondary education. The school unit managerial role for the case of Greek schools is performed by the school principal who has both administrative and educational duties. Statistical analysis included the application of Friedman's test and hypothesis test on questions concerning school manager environmental perceptions and energy-saving habits. According to the results, Greek school managers have a high degree of environmental sensitivity, since 97.6 % agreed or strongly agreed that the main concern should focus on energy saving. Furthermore, 71% of the respondent reported to have good knowledge on solar energy, followed by 64% on wind energy while only 34% are knowledgeable on biomass. Almost all the respondents (99%) agreed that it is important to provide more RES-orientated education through the taught curricula. Concerning energy saving behaviour, around 90% reported that they switch off the lights when leaving the classroom and they close the windows when the air-condition is operating. Hypothesis tests revealed a relationship between the school managers' ecological beliefs, the energy saving habits in the school environment, and the recognition of the importance of environmental education. Conclusions highlighted the need to intensify environmental education programs in the school environment concerning RES in schools. This will lead to a higher level of environmental awareness of both teachers and students and therefore to a more dynamic behaviour towards the effort to “greenify” the school environment.
The inertial energy of generators in a power system plays an essential role in maintaining the transient stability in response to the strike of short-circuit faults. Integration of large quantities of renewable energy resources, such as wind and solar energy, and the reduction in the number of conventional generators can lead to the reduction of the overall system inertia of the power system and may result in their vulnerability to faults. To enable a higher integration of renewable energy and to ensure a reliable operation of the power system, it is imperative that the impact of transient stability criteria be incorporated into Unit Commitment algorithms. This thesis proposes to incorporate an inertia based transient stability constraint in a unit commitment formulation. Algorithm to estimate parameters for the proposed transient stability constraint is developed and presented. A transient stability constrained unit commitment (TSUC) is formulated as a mixed integer linear programming (MILP) model. The effectiveness of proposed method is successfully tested on a 9-bus power system and results are discussed
The inertial energy of generators in a power system plays an essential role in maintaining the transient stability in response to the strike of short-circuit faults. Integration of large quantities of renewable energy resources, such as wind and solar energy, and the reduction in the number of conventional generators can lead to the reduction of the overall system inertia of the power system and may result in their vulnerability to faults. To enable a higher integration of renewable energy and to ensure a reliable operation of the power system, it is imperative that the impact of transient stability criteria be incorporated into Unit Commitment algorithms. This thesis proposes to incorporate an inertia based transient stability constraint in a unit commitment formulation. Algorithm to estimate parameters for the proposed transient stability constraint is developed and presented. A transient stability constrained unit commitment (TSUC) is formulated as a mixed integer linear programming (MILP) model. The effectiveness of proposed method is successfully tested on a 9-bus power system and results are discussed
The outage of power system equipment is one of the most important factors that affect the reliability and economy of power system. It is crucial to consider the influence of contingencies elaborately in planning problem. In this paper, a distributionally robust transmission expansion planning model is proposed in which the uncertainty of contingency probability is considered. The uncertainty of contingency probability is described by uncertainty interval based on the outage rate of single equipment. An epigraph reformulation and Benders decomposition are applied to solve the proposed model. Finally, the feasibility and effectiveness of the proposed model are illustrated on the IEEE RTS system and the IEEE 118-bus system.
Production of electric energy or power. Powerplants. Central stations, Renewable energy sources
Abstract Power electronics–based converters for photovoltaic (PV) systems are susceptible to overcurrents; it is important to design their controllers to reduce the transient current for all viable operating conditions. To design a current controller and find the maximum transient current via simulation‐based techniques, the exact values of the system parameters, initial states, and inputs are required. However, they are not precisely known in practice, some system parameters such as inductances may change over time, and output power and load are variable. The uncertainty in the parameter (filter inductance) and input of the system (injected power) should be considered in the analysis of a PV system controllers as it can degrade their performance, which are designed for the system nominal parameters. This paper employs reachability analysis for a grid‐connected PV system to (1) find the maximum transient current, (2) devise an improved PI current controller and (3) compare the maximum transient current in PI‐ and internal model control (IMC)‐based controllers with uncertain‐but‐bounded input power and inductance error. Simulation and experimental studies showcase the results.
The high penetration of renewable energy sources, combined with a limited possibility to expand the transmission infrastructure, stretches the system stability in the case of faults. For this reason, operators are calling for additional control flexibility in the grid. In this paper, we propose the deployment of switchable reactors and capacitors distributed on the grid as a control resource for securing operations during severe contingencies and avoiding potential blackouts. According to the operating principles, the line reactance varies by switching on or off a certain number of distributed series reactors and capacitors and, therefore, the stabilizing control rule is based on a stepwise time-discrete control action. A control strategy, based on dynamic optimization, is proposed and tested on a realistic-sized transmission system.
The aim of the work is to develop technical measures to improve the quality of the power transmission process through electrical link, which contains a frequency converter based on a PST (phase-shifting transformer) with circular rotation of the output voltage phase in relation to the input, made according to the triangle scheme and controlled by means of power electronics. To achieve this goal, the use of longitudinal inductive elements (chokes) has been proposed as one of the measures that significantly improves the controlled mode parameters in the process of frequency conversion. The problem has been solved by performing computational experiments on simulation models of electrical links, combining two power systems with a frequency of 60 and 50 Hz, respectively. The structure of electrical links at various stages of the study has included several circuit variants of a frequency converter (single-channel circuit, dual-channel with reversing control winding sections, dual-channel circuit without reversing control winding sections) and has developed by authors earlier. In the process of research, the value of inductance of chokes has been changed, as well as their place of connection. The controlled transmission's characteristics have been analyzed as well. The novelty of the work lies in the use of longitudinally included inductive elements as a possible solution to the problem of improving the quality of power transmission when combining power systems with different operating frequencies using static frequency converters. The optimal values of the parameters of inductive elements, comprised between 0.03-0.035Hn for all circuit versions of the converter, have been identified.
Electrical engineering. Electronics. Nuclear engineering, Production of electric energy or power. Powerplants. Central stations
Tight sandstone gas characterized by a wide distribution, local enrichment and a complex gas–water distribution has high exploration potential. This study, using the Xujiahe Formation in the Guang’an gas field as an example, aims to determine the main controlling factors of the enrichment of tight gas through comprehensive analyses of the source rock and reservoir characteristics, pressure evolution and structural effects by using various methods including well logging, geochemistry, mercury injection, reservoir physical properties and formation pressure. The results show that the proximal-source, interbedded hydrocarbon accumulation results from a dispersed hydrocarbon supply, which is the root cause of the widely distributed tight sandstone gas. The abnormally high reservoir pressure caused the enrichment of tight sandstone gas even under insufficient hydrocarbon generation dynamics; in addition, natural gas preferentially accumulated in the relatively high-quality reservoirs under the same hydrocarbon supply, which means that differences in the reservoir physical properties control gas charge in the reservoir. Structure controls the gas–water differentiation under the stable tectonic background, and the higher the structure is, the more abundant the gas–water differentiation is, and the easier pure gas reservoirs form. Therefore, the accumulation and enrichment of tight sandstone gas in the Xujiahe Formation is controlled by source rocks, abnormally high reservoir pressure and the physical properties and structure of the reservoir.
Production of electric energy or power. Powerplants. Central stations, Renewable energy sources
In order to gain an understanding of the mechanism of thermal performance increase in the shell side, a shell and tube heat exchanger is proposed in this study. Numerical investigations of the shell side fluid flow and heat transfer are performed using CFD Fluent software based on the model. The profiles and axial velocity fields, as well as the profiles and temperature distribution at the heat exchanger level were obtained for the whole geometry. The speed increases by 12 % of the reference speed in the shell.