Power Shortage Research Articles

The Influence of Stability in New Power Systems with the Addition of Phase Modulation Functions in Thermal Power Units

The addition of phase modulation function technology to thermal power units is one of the most effective measures to solve dynamic reactive power shortages in the construction process of new power systems. In this paper, the influence of the phase modulation function transformation of thermal power units on the stability of a new power system is studied. Firstly, the new power system stability index is deeply analyzed, and an evaluation system for power system transient stability is constructed from five key dimensions: transient voltage, static voltage, power angle stability, power flow characteristics, and grid support. Secondly, a fuzzy comprehensive evaluation method considering the subjective and objective comprehensive weights is proposed, and the influence of the phase modulation transformation of the thermal power unit on the stability of the receiving-end power grid is quantitatively analyzed. Finally, a CEPRI36 node example model was built based on the PSASP v.7.91.04.9258 (China Electric Power Research Institute, Beijing, China) platform to verify the accuracy and effectiveness of the proposed method. The results show that the proposed method can quantitatively analyze the impact of adding a phase modulation function to thermal power units on the stability of the power system. At the point of renewable energy connection, the static voltage stability index improved by 42.9%, the transient power angle stability index improved by 32.1%, the multi-feed effective short-circuit ratio index improved by 33.9%, and the comprehensive evaluation score improved by 14.7%. These results further indicate that adding a phase modulation function to thermal power units can provide a large amount of dynamic reactive power support and improve the voltage stability and operational flexibility of the system.

Low-Frequency AC Multiport Asynchronous Grid Connection System to Optimize Generation Costs and Mitigate Bottlenecks

Renewable energy sources continue to increase due to the energy transition; thus, the generation output of conventional power sources is decreasing. The installation of renewable energy sources can lead to the concentration of these sources depending on geographical characteristics, which may cause bottlenecks between the renewable energy generation sites and load centers, and such bottlenecks can result in power shortages in load centers and may cause issues that limit the integration of renewable energy. Thus, this paper proposes the application of an LFAC multiport asynchronous grid connection system to solve these problems, where the frequency conversion device uses a variable frequency transformer (VFT). In addition, the installation location of the proposed LFAC multiport asynchronous grid connection system is selected using a grid partitioning technique, and the optimal power flow is performed to minimize the generation costs. The grid partitioning was conducted using the IEEE 39 bus system, and the feasibility of the proposed LFAC multiport asynchronous grid connection system was verified through simulation tests of the generation and load demands in the grid. In addition, the VFT control and optimal power flow control performances were confirmed through MATLAB/Simulink.

CHALLENGES AND BENEFITS OF USING INFORMATION TECHNOLOGIES IN TEACHING CHEMISTRY IN UKRAINE DURING WARTIME

The education sector, which is one of the most important aspects of public life, has undergone critical changes due to the full-scale invasion of Russia in Ukraine. Educators and students have been forced to a rapid shift from traditional to digital learning methods. Chemical education has adapted to the new reality by using a number of digital platforms, virtual laboratories, and other IT tools for distant learning. These innovative educational technologies have become particularly useful in chemistry teaching, where interactive tools help replace hands-on experiments in wartime circumstances, where access to traditional laboratories is unsafe or impossible. However, the transition to digital learning in Ukraine during the current period not only has complexities on its own, but is also accompanied by significant challenges caused by war conditions, including power shortages, limited Internet access, and digital inequality, especially in war-torn and rural areas. The issues of digital literacy, content localization, cybersecurity, and students’ and educators’ psychological well-being present further complications. Developing and expanding access to relevant, localized chemistry educational content will be essential to closing the education gap and maintaining long-term sustainability. In the post-war period, it is appropriate to implement a blended learning model that combines digital tools with offline laboratories, which is critical for sustainable recovery, promoting community rebuilding, developing practical student skills, and the sustainability of the Ukrainian education system in general.

OPERATING PECULIARITIES OF STANDARD COOLING SYSTEMS OF ENGINES AT HIGH ALTITUDES

The item under test was the engine without its standard facility-based cooling systems, the lack of which makes it impossible to operate as a power unit of a vehicle in a great majority of experimental research of internal combustion engines at high altitudes. The findings may create a wrong impression of the range of power ratings and economic parameters of the engine when operating at high altitudes because changes in atmospheric conditions exert an effect on the running efficiency of its standard systems as well. It is established that the efficiency loss of the cooling system may cause a forced power limitation of the engine as a result of the experimental research of the diesel engine equipped with all standard facility-based systems at very high altitudes. Thus, the shortage of power may significantly exceed the power loss of the engine due to air density reduction at high altitudes.

Understanding SOE responses to the energy crisis in Nigeria and South Africa

This aim of this paper is to present an understanding State-Owned Entities (SOE’s) responses to the energy crisis in Nigeria and South Africa. The energy crisis in both Nigeria and South Africa has posed significant challenges, with both countries experiencing severe power shortages that have impacted economic growth and the quality of life. State-Owned Enterprises (SOEs) in the energy sector, such as Nigeria's NESCO and South Africa's Eskom, have traditionally been central to efforts of ensuring energy security. The paper therefore through a qualitative method of research, attempts to reveal the responses of the SOE’s in these states to address the energy crisis. Hence, it concludes that South Africa responded by unbundling Eskom and Nigeria privatising the energy sector. But these mechanisms are yet to solve the energy crisis.

Feasibility Study of Wind Farm Using RETScreen Model: A Case Study of Al-Razaza Site, Iraq

In recent years, interest in renewable energies has increased due to their clean, renewable, and inexhaustible characteristics. Iraq faces a significant challenge in the shortage of electric power. The green economy, especially in renewable energy, has become one of the world's main pillars, especially after the remarkable rise in greenhouse gas emissions (GHG) from fossil fuel combustion for electricity production. This study evaluates wind farm feasibility, assessing costs, revenue, and financial viability. It identifies potential hazards and difficulties, enabling developers to develop strategies to mitigate risks during project creation and operation. This paper aims to undertake a feasibility study to assess the viability of constructing a wind farm with a capacity of 340 megawatts at the Al-Razaza location in Karbala province. The study site utilized authentic data from the meteorological tower installed on the premises. The data employed spanned three years, encompassing a comprehensive and integrated dataset for the study. RETScreen, a powerful model renowned for its energy efficiency analysis and sustainable decision-making capabilities, was employed. Through the application of RETScreen, a meticulous assessment and analysis of the intricate project components were facilitated. A study of risk analysis was conducted to ascertain the impact of various parameters on the payback period of the project. The findings showed that the capacity factor of the wind farm is 22.3%, which is relatively low, the simple payback period is 10.3 years, and the energy production cost is 0.059$/KWh.

Design of Local Micro-Grids to Solve the Electricity Shortage in Iraq Cities

Iraqi cities suffer from a shortage of electric power due to poor production and deterioration of transmission and distribution lines. There is no prospect currently for improving the grid, despite the government's promises. So it has become necessary to find alternatives, at least at the local level. This research, presented a successful alternative, which applied all over the world, which is the local microgrid. Also, it’s developed a design for this microgrid that suits the conditions of Iraq and supports the integration of clean energy produced by the consumer. The results indicate the success of investing in this microgrid by small investors, foreign companies or local administrations of the cities that want to develop their cities in isolation from the problems of the country's national electrical grid. This solution reduce the pressure on the national grid on one hand and improve the electricity service for the consumer on the other hand, by providing the pivotal key to the solution, which is replacing the blind system of paying wages (for electricity service) currently followed in Iraq with the billing system followed in all developed countries of the world. This solution provides the possibility of deploying the economic solar PV system (without batteries) in Iraqi houses to reduce the bills and also allows personal monitoring of electricity consumption so that the consumer can reduce loads during peak times to reduce bills as well.

Factors Militating the Effective Utilization of the Nursing Process in Patient Care: A Descriptive Survey of Nurses in a Tertiary Hospital in North West, Nigeria

Nursing process is the systematic, patient-centered approach used by nurses to guides individualized nursing care; thereby enhance quality of patient care and outcomes for both the patient and family members, as an organized framework for the practice of nursing. The purpose of this study was to investigate the factors militating against effective utilization of nursing process in patient's care among nurses in a Tertiary Hospital in north-west, Nigeria. The research design employed in the study was across sectional survey, sample size of 108 but 97 valid for data analysis. The nurses who were proportionately selected participated in the study. The data were derived from the administration of copies of questionnaire. The instrument was validated by the researcher’s supervisor and two other experts from faculty of nursing Ladoke Akintola University of technology. A Cronbach’s alpha reliability coefficient of 0.82 is indicative of the reliability of the instrument. Data collected were analysed using SPSS version 20 version. Hypothesis was tested using Chi square set at p value 0.05. The findings revealed that greater number (92%) understood that nursing process is a problem solving technique for nurses and (80, 83%) utilizes nursing process in patients care. Majority of participants 63.9% (Mean = 1.71) established that shortage of human resources, 59.8% (Mean = 1.86) lack motivation and 53.6% (Mean = 1.53) different approaches adopted by nurses were seen to impact the use negatively. Experience, and educational Level were statistically found to be significant determinants for nursing process utilization (p=0.00, and 0.02). Based on the findings, it can be concluded that there exist a significant relationship between nurse’s years of experience and knowledge of nursing process utilization and the rate of utilization. Recommendation that adequate and relevant materials be provided for nurses in order to achieve and perform their respective tasks at the optimal best, the management should equally employed more nurses to breech the chronic shortage of man power.

The Eectricity Crisis and the Feasibility of Nuclear Energy in Egypt

The power outage crisis is increasing in Egypt, negatively affecting many other sectors such as industry, agriculture, and trade. In light of the lack of sufficient capacity to meet the growing needs of consumers, which has led to regular power shortages and power outages. While Egypt needs additional energy, the production of gas and oil needed to generate thermal energy decreased in 2014, and Egypt moved from an exporter of natural gas to a net importer. In addition to this, the volume of subsidies allocated to energy increased, the rise in global prices for oil and natural gas, and the need for huge investments to create Power generation plants, development of transportation networks, and distribution of electrical energy, which led to pressure on the general budget. A continuous and reliable supply of electricity is needed for Egypt's social and economic development. Accordingly, the government encouraged the development of new energy, invited the private sector to participate in energy generation, and a number of government reforms were made in order to enhance competition in the energy market, which required the need to study the possibility of providing it using nuclear energy. Its stations have a high load capacity, operate almost at full capacity all the time, are characterized by the stability of the electrical network and energy independence, and avoid the risks of fuel price shocks, and the costs of generating electricity from them decrease with increasing production. The importance of this research lies in highlighting the challenges facing the structure of the electricity sector in Egypt, and studying the advantages enjoyed by nuclear energy as the most important renewable energy sources in the world. Its importance also lies in comparing nuclear energy with other energy sources, and trying to benefit Egypt from obtaining this energy for use. In economic development projects, rationalizing tariffs and supporting their access to the poor. <i>This research is divided into</i>:<i>The first topic</i>: The electricity generation crisis in Egypt and a development vision for the contribution of nuclear energy to its solution, <i>The second topic</i>: trends in development planning for establishing nuclear plants in Egypt. The electricity generation crisis in Egypt and a development vision for the contribution of nuclear energy to its solution.

Optimization of emergency frequency control strategy for power systems considering both source and load uncertainties

With the increasing integration of renewable energy sources and the presence of numerous controllable loads such as electric vehicles and energy storage in the modern power system, higher nonlinearities and uncertainty both sources and loads are introduced. These factors pose challenges in achieving fast and accurate emergency frequency control. Therefore, this paper addresses the issue of dual source-load uncertainties in power system and presents an optimization strategy based on the Soft Actor Critic (SAC) algorithm that involves the participation of controllable loads in emergency frequency control. Firstly, the spatio-temporal uncertainties of wind farm power output on power supply side and power demand on the load side are described using Weibull and normal probability distributions, respectively. Secondly, an improved Markov Decision Process (MDP) model for emergency frequency control is established, which considers the characteristics of the dual source-load uncertainties. Finally, an optimization of the SAC algorithm is conducted based on Deep Reinforcement Learning (DRL), aiming to achieve rapid system frequency recovery and minimize the cost of removing controllable loads. The presented approach in the paper enhances the emergency frequency control strategy for uncertain power systems and effectively addresses the issue of source-load uncertainty compounded by fault power shortages.

Retrofitted CCS technologies enhance economy, security, and equity in achieving carbon zero in power sector

Retrofitting existing fossil fuel power plants with carbon capture and storage (CCS) technology could reduce carbon emissions while avoiding stranded asset, which will be important in facilitating a just transition of the global power sector. Although some studies have explored the cost-effectiveness and abatement potential of retrofitted CCS technologies, elaborate system modeling of full-chain retrofitted CCS technologies considering multiple technology types requires further research. Here, we developed an hourly-resolution intertemporal dynamic power system optimization model that elaborately considers three retrofitted CCS technologies for coal-fired and gas-fired power plant in addition to eleven power generation technologies and two energy storage technologies and applied it to evaluate the role of retrofitted CCS technologies in achieving carbon neutrality in China's power sector. The results show that, compared with no retrofitted CCS power system, the high development of retrofitted CCS can reduce the future installed capacity and power generation demand of China's power sector by up to 605GW or 10.5 % (in 2040) and 0.17 PWh or 0.9 % (in 2060), respectively. The cumulative system decarbonization costs and electricity supply costs will decrease 6.2–8.2 % and 2.1–2.6 % by 2060, respectively, due to the savings in related costs of newly built plants and reduction in potential power shortages, in addition to avoidance of large coal-fired power stranded assets. The developed model could be a reference for other countries, and in China and perhaps in other economies with coal-dominant power systems, policies advocating the development of retrofitted CCS should be strengthened.

Increases in Night Lights Intensity Reveal Extreme Events: A Case of Study on the Ongoing Conflict in Ukraine

Abstract. Analyzing night lights images allows identifying and monitoring affected areas during conflicts, as an overall decrease in brightness indicates abandoned or destroyed buildings, curfews, or power shortages. While detecting decrease in lights intensity is an established technique to identify critical areas during conflicts, the causes of appearing bright lights have not been extensively studied. An increase in brightness may be related to extreme events, such as fires resulting from bombing. This paper shows several examples supporting this new use of these images, validated using high-resolution optical earth observation data and ancillary information sources in the frame of the conflict in Ukraine which has been ongoing since February 2022.

Decentralization of renewable energy sources based optimum scheduling and management through a virtual power plant

Abstract In this paper, renewable resources and co-generation units are grouped together to perform optimized operational scheduling in a virtual power plant (VPP) system. Renewable sources consist of solar photovoltaic, wind, and fuel cell units that are equipped together with a cogenerating unit to intensify the system's dependency in case of power shortage from renewable sources. The uncertainty aspect is investigated for the developed system as renewables are associated, and its impact on network operation is discussed. Storage provision is facilitated in the form of flexible and spinning reserves in which electric vehicle (EV) and energy storage systems (ESS) increase the system reliability by ensuring continuity of power supply. Optimal scheduling is carried out from both economic and environmental perspectives in which the net profit of the system is improved and the generated emissions are reduced by considering dual scheduling i.e., day-ahead (DA) and proposed 15 min interval. Moreover, a nature-inspired metaheuristic red fox optimization (RFO) is employed to handle the VPP problem and the results with the context to net profit and emission are also compared with work available in the literature. Finally, the proposed approach is promising in terms of higher computational efficacy and reveals the suitability of the VPP system.

Adaptive robust self‐scheduling for a wind‐based GenCo equipped with power‐to‐gas system and gas turbine to participate in electricity and natural gas markets

AbstractIntegrating renewable energy, particularly wind generation, into power systems brings significant uncertainty and intermittency, challenging generation companies (GenCos) to maintain economic operations. This paper proposes a strategy for a wind‐based GenCo equipped with a gas turbine and a power‐to‐gas (PtG) system to balance wind variability. The gas turbine offsets power shortfalls by consuming natural gas, while the PtG system absorbs excess wind energy, converting it to natural gas and injecting it into the natural gas network as a form of storage. The GenCo operates in day‐ahead electricity and natural gas markets and the real‐time electricity market, addressing uncertainties from wind output, energy prices, and natural gas access. A tri‐level adaptive robust optimization model is introduced for the GenCo’s short‐term operational scheduling. At the first level, decisions related to the GenCo's participation in the day‐ahead electricity and natural gas markets are made. The second level deals with determining the worst‐case realization of the uncertainties, constrained by the budget of uncertainty and the limited range of variations of uncertain variables. The third level sets the operational strategy on the actual day, considering power and gas balance, as well as constraints for the wind farm, gas turbine, and PtG unit. A column & constraint generation (C&CG) algorithm is used to solve the model. Numerical results demonstrate the model’s effectiveness in various case studies, showing that the GenCo can manage wind uncertainties, benefit from arbitrage opportunities in electricity and gas markets, and improve economic outcomes. This approach supports the broader integration of renewable energy into power systems.

Stochastic optimization of a hybrid photovoltaic/fuel cell/parking lot system incorporating cloud model

The interaction and optimization of electric parking lots (EPLs) with hybrid renewable energy to exchange power and improve the system load reliability has been welcomed systems in energy industry, but it is accompanied by challenges such as uncertain parameters, and also implementing the optimal energy management. This paper proposes a novel stochastic optimization framework for a hybrid energy system including photovoltaic resources, hydrogen storage based-fuel cell integrated with an EPL (PV/FC/EPL) aiming for minimization of the total net present cost (TNPC) while ensuring the maximum probability of power shortage (PPSHmax) to meet a commercial load in Tianjin, China using the real meteorological data. A new improved kepler optimization algorithm (IKOA) utilizing the golden sine strategy is applied to optimize system component sizes and EPL charge/discharge. In a deterministic scenario, the optimal system configuration ensures cost-efficiency and reliability for load supply. Also, a new stochastic modeling framework is proposed using the Cloud Model (CM) to evaluate the effect of uncertainties in irradiance, temperature, and system demand on TNPC and PPSH. Deterministic findings reveal enhanced reliability and reduced TNPC through FC and EPL overlap during power shortages, compared to systems lacking EPL. Specifically, TNPC and PPSH are $8,632,643 and 1.45 %, respectively, for PPSHmax = 2 % over 20 years of operation. However, stochastic optimization demonstrates a 10.82 % increase in TNPC and an 8.67 % decrease in PPSH compared to the deterministic model under PPSHmax = 2 %, indicating heightened cost and reduced reliability when uncertainties are considered. This underscores the efficacy of the cloud model-based stochastic approach in addressing uncertainty in hybrid system optimization. Also, it reveals fluctuations in optimal cost and reliability values with changes in cloud droplet distribution around the expected value, emphasizing the significance of stochastic modeling for robust decision-making in hybrid energy systems. Moreover, evaluating the incorporating the penalty for the system's inability to supply the load, changing the storage investment cost, and interest rate variations on the system optimization cleared considerable effect of the system cost and reliability.

Enhancing the Reliability of Weak-Grid-Tied Residential Communities Using Risk-Based Home Energy Management Systems under Market Price Uncertainty

This paper evaluates the reliability of smart home energy management systems (SHEMSs) in a residential community with an unreliable power grid and power shortages. Unlike the previous works, which mainly focused on cost analysis, this research assesses the reliability of SHEMSs for different backup power sources, including photovoltaic systems (PVs), battery storage systems (BSSs), electric vehicles (EVs), and diesel generators (DGs). The impact of these changes on the daily cost and the balance of energy source contribution in providing electrical energy to household loads, particularly during power outage hours, is also evaluated. To address the uncertainty of electricity market prices, a risk management approach based on conditional value at risk is applied. Additionally, the study highlights the impact of community size on energy costs and reliability. The proposed model is formulated as a mixed-integer nonlinear programming problem and is solved using GAMS. The effectiveness of the proposed risk-based optimization approach is demonstrated through comprehensive cost and reliability analysis. The results reveal that when electric vehicles are used as backup power sources, the energy index of reliability (EIR) is not affected by market price variations and shows significant improvement, reaching approximately 99.9% across all scenarios.

Long-Term Optimal Scheduling of Hydro-Photovoltaic Hybrid Systems Considering Short-Term Operation Performance

Integrating photovoltaic power stations into large-capacity hydropower stations is an efficient and promising method for regulating large-scale photovoltaic power generation. However, constrained by the time step length, traditional long-term scheduling of hydro-PV hybrid systems does not adequately consider short-term operational performance indicators, resulting in sub-optimal scheduling plans that fail to coordinate the consumption of photovoltaic power and the utilization of water resources in the basin. To address this, this study established a long-term optimal scheduling model for hydro-PV hybrid systems. This model overcomes the limitation of the time step length in long-term scheduling by incorporating long-term power generation goals and short-term operation performance targets into the long-term optimal scheduling process based on scheduling auxiliary functions. In case studies, the optimised model balanced the long-term power-generation goals and short-term operational performance targets by redistributing energy across different periods. Compared to optimization models that did not consider short-term operation performance, in a typical normal year, the model effectively reduced the electricity curtailment volume (28.54%) and power shortage volume (10.91%) of the hybrid system while increasing on-grid electricity (0.03%). Similar improvements were observed in wet and dry years. These findings provide decision support for hydropower scheduling in the context of large-scale photovoltaic power integration.

Achieving gigawatt-scale green hydrogen production and seasonal storage at industrial locations across the U.S.

Onsite production of gigawatt-scale wind- and solar-sourced hydrogen (H2) at industrial locations depends on the ability to store and deliver otherwise-curtailed H2 during times of power shortages. Thousands of tonnes of H2 will require storage in regions where subsurface storage is scarce, which may only be possible using liquid organic H2 carriers. We evaluate aboveground system with a focus on providing technical insights into toluene/methylcyclohexane (TOL/MCH) storage systems in locations suitable for gigawatt-scale wind- and solar-powered electrolyzer systems in the United States. Here we show that the levelized cost of storage, at a national median of US dollar $1.84/kg-H2 is spatially heterogeneous, causing minor impact on the cost of H2 supply in the Midwest, and significant impact in Central California and the Southeast. While TOL/MCH may be the cheapest aboveground bulk storage solution evaluated, upfront capital costs, modest energy efficiency, reliance on critical materials and pre-sulfided catalysts, and greenhouse gas emissions from heating are opportunities for further development.

Centralised Control and Energy Management of Multiple Interconnected Standalone AC Microgrids

When microgrids operate autonomously, they must curtail the surplus of renewable energy sources (RES) while minimising reliance on gas. However, when interconnected, microgrids can collaboratively minimise RES curtailment and gas consumption due to the ability of exchanging power. This paper presents a centralised controller and energy management of multiple standalone AC microgrids interconnected to a common AC bus using back-to-back converters. Each microgrid consists of RES, a battery, a gas-powered auxiliary unit, and a load. The battery’s state of charge (SOC) is controlled and is used in the AC bus frequency to indicate whether the microgrid has a surplus or shortage of power. High-level global droop control exchanges power between the microgrids. The optimisation problem for this interconnected system is modelled cooperatively to determine the optimal dispatch solution that minimises the energy cost from the auxiliary unit. The optimal dispatch is solved in three cases using the Nelder–Mead simplex algorithm under different settings: one-variable optimisation, three-variable optimisation with the standard droop equation, and three-variable optimisation with a modified droop equation. The optimised performance results are compared with those of the non-optimised benchmark to determine the percentage of optimal performance. The simulation results show that the total energy cost from the auxiliary unit is minimised by 8.98%.

Complementary Analysis and Performance Improvement of a Hydro-Wind Hybrid Power System

Hydropower as a flexible regulation resource is a rare choice to suppress the ever-increasing penetration of wind power in electrical power systems. The complementary characteristics and performance improvement of a hydro–wind hybrid power system based on a mathematical model of the hybrid power system is studied in this paper. This established model takes into account the stochastic variation in wind speeds in the wind power subsystem and the hydraulic–mechanical–electrical coupling characteristics of the hydropower subsystem. The complementary analysis is conducted based on the evaluation variables outputted by the established model, such as the wind power, hydro-regulation power, hydraulic power, and frequency. To make full use of the regulation capability of the hydropower system, the optimization of parameter settings is also carried out to improve complementary performances of the hybrid power system. The results from the complementary analysis show the detailed characteristics of hydro–wind coordinated operation under different types of real wind speeds. Here, 95% of installed hydro-capacity is used to complement the power shortage of the intermittent wind energy under the low wind speed. Alternatively, only around 66% of the installed hydro-capacity can be utilized to cope with the fluctuation in wind power under the medium and high wind speeds before the optimization of parameter settings. The recommended values and change rules of the control, hydraulic, and electrical parameters for the hydropower system are subsequently revealed from the analysis of parameter settings to contribute to a stable and safe hybrid power system. The results show that the optimized parameter can increase the maximal regulating capacity of the hydropower system by nearly 9 MW, approximately a sixth of the total installed hydropower capacity. The method and results obtained in this paper provide theoretical and technical guidance for the safe and economical operation of power stations.