Polityka Energetyczna - Energy Policy Journal

This study aims to investigate partial discharges (PD) occurring in micro-sized voids within the polymer insulation of high-voltage power cables, which serve as critical early indicators of internal insulation faults and potential failures. Accurate analysis and modeling of these PD phenomena are essential for improving the reliability and safety of power transmission systems. In this research, a detailed simulation of partial discharge behavior was conducted using MATLAB/Simulink software, focusing on the influence of void size, as well as the amplitude and frequency of the applied sinusoidal voltage, on PD characteristics. The simulation model incorporates key physical parameters to represent the micro-void environment and electrical stress conditions accurately. Key findings demonstrate that as the diameter of the gas-filled void increases, both the number of discharges within each voltage cycle and the charge transferred during individual partial discharges increase significantly. Additionally, an increase in the amplitude of the applied voltage results in a greater number of discharges per period, indicating heightened insulation stress. The study also reveals a proportional relationship between voltage frequency and the average partial discharge current, where higher frequencies lead to increased PD activity. A novel aspect of this work is the ability to correlate partial discharge measurements obtained under high-frequency voltage conditions with those at the industrial standard frequency of 50 Hz. This correlation facilitates more accurate interpretation and prediction of insulation degradation and remaining service life in polymer-insulated cables and other high-voltage energy facilities.

This research addresses the growing challenges posed by the increasing power demands of modern Space Rocket Complexes (SRCs), particularly in relation to integrating various types of electrical consumers. As SRC systems become more complex, ensuring electromagnetic compatibility and maintaining electric power quality are now critical and economically significant issues. The main objective of the study is to develop an algorithm for the optimal selection of power supply system (PSS) structures for SRCs, with a strong focus on electric power quality management. Several PSS configurations were analyzed and compared, each evaluated for reliability, control efficiency, and adaptability to operational conditions. A systematic algorithm and corresponding block diagram were created to guide the selection process, integrating power quality parameters into early design decisions. The methodology was tested using the Cyclone-4 launch complex as a case study. Within this framework, a prototype electric power quality control system was designed and partially implemented. Experimental testing validated the effectiveness of the proposed approach, confirming that early integration of power quality considerations significantly enhances system reliability and economic performance. Key findings emphasize the importance of incorporating power quality criteria into SRC infrastructure planning to ensure stable operation under complex and variable conditions. This study ultimately contributes to the development of more robust and efficient power systems for future space missions. It offers a structured and practical approach for selecting and managing power supply systems in high-demand aerospace environments, emphasizing the value of proactive quality control and comprehensive system design.

This study aimed to develop and evaluate the effectiveness of a new Savonius wind turbine scheme featuring a vertical fixed axle, which offers advantages in reducing metal intensity and operating time. The study employed theoretical analysis of existing wind turbine designs, a fixedaxle modular design, and aerodynamic modeling of the rotor profile to enhance the plant’s efficiency. As a result of the study, a new scheme of a Savonius wind turbine with a vertical fixed axle was developed. The proposed design helped significantly reduce the metal intensity of the plant by approximately 30%, resulting in lower manufacturing costs. The absence of a rotating shaft and its replacement with a fixed axle resulted in a reduction of friction in the support, thereby increasing the plant’s efficiency. Dynamic forces on the structure were also reduced, contributing to longer bearing life. The proposed design reduced metal consumption by approximately 1.5 times, resulting in a 35% reduction in production costs. Less frequent maintenance, once every two years instead of every six months, reduces operating costs by up to 40%. Reduced friction in the bearings and reduced dynamic loads increase reliability and extend bearing life by 25%. All in all, these factors increase the financial efficiency and competitiveness of the turbine in the renewable energy market. The practical benefits of the research for stakeholders are that engineers are able to implement simplified and reliable design solutions that reduce bearing loads and increase turbine efficiency.

The intermittency of natural renewable energy sources poses a significant challenge to supplying electricity in rural areas that rely on standalone renewable energy systems. Although battery storage is often used to address this issue, it has several limitations, especially in hot climate regions where performance and longevity are compromised. Ensuring reliable and accessible electricity in these areas is essential for promoting economic development and improving quality of life. This study aims to develop a novel hybrid power system to provide a sustainable and dependable energy solution, that integrates solar photovoltaic (PV), micro-hydro, biomass, and hydrogen storage in one hybrid system, where this specific combination has not been explored in previous literature. After conducting a comprehensive field survey to evaluate the available natural resources and design the system, the proposed model was subsequently simulated in HOMER Pro software. The testing results indicated a high degree of compatibility between the tested energy sources, with each one contributing well to an ongoing year-round energy supply. The largest shares were solar PV 64.8% and micro-hydro 24.3%. Biomass and hydrogen storage both accounted for 6% and 5%, respectively, particularly in periods when other sources were not available. The lessons learned from these findings offer valuable input for shaping future energy policy and represent a consultable kit to be used in similar areas, as well as a direction for the next stages of the hybridization process on advanced energy systems for further research.

This research focuses on investigating and improving technical solutions for utilizing evacuated tube heat collectors and solar concentrators to enhance heat transfer efficiency and adapt solar installations to integrate with existing fuel oil heating systems. The research methodology included the development of a mathematical model to describe heat transfer in evacuated tube heat collectors, the creation of an algorithm to calculate the system’s design parameters, and numerical modeling to assess temperature characteristics, efficiency, and the impact of key factors affecting the system. As a result of the study, the developed mathematical model made it possible to accurately describe the processes of heat transfer and the interaction of solar radiation with evacuated tube heat collectors and solar radiation concentrators, and to identify analytical dependencies linking the design parameters of the system (pipe diameter and module length) with heat engineering characteristics such as the temperature of the heat carrier and the efficiency of heat transfer. During the study, the relationship between the geometric parameters of the system, solar flux, reflection coefficient, and angular inaccuracy was investigated, which helped identify key factors affecting the efficiency of solar energy capture and the temperature distribution within the system. Numerical calculations have shown that increasing the system’s length and adjusting the diameter of the pipes significantly improved the efficiency of solar radiation and affected the coolant’s temperature. The paper also analysed the temperature characteristics, including the effect of the coolant flow rate and its distribution along the length of the tube heat collector. The calculation results showed that to optimize the system, it is necessary to consider the interaction of various parameters, including geometry and radiation characteristics, in order to maximise the efficiency of solar power plants. Additionally, the study confirmed the relationship between the receiver diameter and the concentration number, enabling a more accurate prediction of the system’s efficiency under various operating conditions. Thus, the results obtained can be used to optimize the design of solar thermal systems, improve their efficiency, and accurately calculate design parameters.

Assessing customer satisfaction with the quality of electricity service provides important solutions to improve service quality, especially for a competitive electricity market. In Vietnam, the competitive retail electricity market is at the beginning stage, which requires the improvement of its service quality and customer satisfaction for the competitiveness advantage. The study presents the construction of a set of indicators to evaluate customer satisfaction in the electricity sector in Hanoi city, Vietnam, by four customer groups, including administration, resident, industry, and commerce. The novel research method of quantifying and evaluating electricity customer satisfaction is applied by combining the SERVPERF model to build a set of survey questions, descriptive statistics, and linear regression methods to analyze the results, and the Bootstrap to determine the weights of indicators. The study results showed that there was a clear difference in the assessment of customer satisfaction according to five criteria of service quality and four customer groups. The administration customer group had the highest satisfaction level (4.47/5.00 points), followed by the commerce group (4.41/5.00 points); the two groups of residents and industry had the same assessment level of 4.39/5.00 points. The overall score of customer satisfaction in Hanoi city was 4.41/5.00 points. Besides, the weights of the indicators also had a clear difference. The business image plays the most important role, contributing 21.39% to the customer satisfaction score, followed by customer service and communication (20.58 and 20.39%). Information on safety and power price, and power supply reliability contribute to the small shares of the overall customer satisfaction (19.34 and 18.30%). The study suggests that the Hanoi Electricity Company should focus on the most important indicators, and the least satisfied indicators, e.g., business image and information on safety and power price.

The global energy transition toward sustainability requires frameworks that integrate technical, economic, and social aspects. Stakeholder involvement is crucial in energy system modeling and planning. This study systematically reviews stakeholder involvement techniques in energy system modeling by employing a SWOT analysis to evaluate engagement strategies. It aims to examine the effectiveness of various approaches to stakeholder participation and explore approaches for incorporating stakeholders into decision-making to enhance public trust and acceptance of energy transition models. This study identifies and analyses three primary engagement approaches: information, consultation, and collaboration. A SWOT analysis was conducted to assess the strengths and weaknesses of each approach. The information approach effectively disseminates knowledge but is limited by its unidirectional nature. The consultation approach facilitates two-way dialogue but may struggle to incorporate stakeholder input effectively. The resourceintensive collaborative approach offers opportunities for enhanced knowledge sharing and ongoing stakeholder engagement. The study concludes that informational and consultative approaches are the most effective when utilized as components of a broader collaborative framework. These findings contribute to the knowledge base for modelers, policymakers, and researchers engaged in energy transition planning and offer valuable insights for developing more socially equitable energy transition strategies.

In the face of the global energy transition and the urgent need to reduce CO2 emissions, hydrogen is emerging as a key energy carrier whose widespread adoption depends on the development of efficient and safe transmission infrastructure. Constructing new hydrogen networks involves high costs and long implementation times; therefore, this article analyzes the potential for adapting existing natural gas transmission infrastructure for hydrogen transport. Two main approaches are assessed: blending hydrogen with natural gas and repurposing selected pipelines for pure hydrogen transmission. The article discusses critical technical aspects, including the impact of hydrogen on materials, the risk of hydrogen embrittlement, safety, and operational requirements. The regulatory analysis covers both Polish and EU legal frameworks, with special attention to new standards and certification systems that facilitate hydrogen integration into the current energy system. Examples of pilot and commercial projects across Europe are presented, highlighting Poland’s strategic role in the development of a hydrogen economy. The findings indicate that adapting existing infrastructure can achieve significant cost savings (up to 90% compared to building new networks) and accelerate the achievement of climate goals. The article also identifies key challenges, such as leak detection, equipment compatibility, and the need for regulatory clarity, which must be addressed to enable a safe and effective energy transition. This work aims to provide decision-makers, investors, and experts with interdisciplinary knowledge essential for planning and implementing modern hydrogen infrastructure.

This research focuses on reducing harmful emissions during hot blast stove (HBS) operation by enhancing the automated control system for checkerwork heating. The primary sources of emissions, including nitrogen oxides (NO_x), sulfur oxides (SO_x), and carbon oxides (CO, CO₂), generated during the combustion of blast furnace gas, are analyzed. The authors propose improving the automated control system by implementing feedback on fuel combustion quality, continuous monitoring of exhaust gas composition, and real-time assessment of the fuel’s calorific value. The system’s structure includes regulating combustion airflow, continuous monitoring of blast furnace gas calorific value, evaluating combustion efficiency through O₂, CO, and CO₂ content analysis in exhaust gases, and adjusting the combustion process according to the mode map, maintaining the dome temperature within 1,350–1,420°C to minimize NO_x formation. These measures contribute to reducing NO_x emissions, enhancing energy efficiency, and stabilizing the temperature regime. The proposed solutions offer a cost-effective approach to emission reduction and can be seamlessly integrated into existing metallurgical enterprise systems.

This paper explores the challenges of economically evaluating environmental protection measures, emphasizing their role in shaping sustainable national economic development. These measures contribute to ecological safety, quality of life, and economic growth while conserving natural resources. Effective economic evaluation ensures long-term benefits from ecosystem preservation and sustainable resource use. The study proposes evaluating efficiency using indicators like service payment costs, current expenses, and the volume of services rendered. Using the coefficient method, the analysis focuses on Ukraine and calculates ratios of payment and current expenses to service volume. Findings show that only the water supply, sewage, and waste management sectors fully offset their costs through services rendered. In other sectors (construction, finance, public administration, defense), only partial cost recovery occurs. An environmental functional analysis method was also applied, assessing efficiency by comparing service volume to costs. A total efficiency coefficient was calculated against inefficiency metrics, revealing sector-specific trends and cost-related drivers. The paper highlights the importance of adjusting costs when higher service volumes are unattainable, ensuring more accurate efficiency assessments. While grounded in Ukraine’s context, the findings are relevant to EU countries prioritizing sustainable development. Applying these methods across the EU could support more effective, adaptable strategies for economic evaluation of environmental protection and advance the implementation of ecologically sustainable economies.