Secondary Energy Source Research Articles

Design and performance evaluation of a multi-load and multi-source DC-DC converter for efficient electric vehicle power systems

This paper introduces the design and comprehensive performance evaluation of a novel Multi-Load and Multi-Source DC-DC converter tailored for electric vehicle (EV) power systems. The proposed converter integrates a primary battery power source with a secondary renewable energy source—specifically, solar energy—to enhance overall energy efficiency and reliability in EV applications. Unlike conventional multi-port converters that often suffer from cross-regulation issues and limited scalability, this converter ensures stable power distribution to various EV subsystems, including the motor, air conditioning unit, audio systems, and lighting. A key feature of the design is its ability to independently manage multiple power loads while maintaining isolated outputs, thus eliminating the inductor current imbalance that is common in traditional systems. Experimental validation using a 100 W prototype demonstrated the converter’s ability to deliver stable 24 V and 48 V outputs from a 12 V input, with output voltage deviations kept within ± 1%, significantly improving upon the ± 5% deviations typically seen in existing converters. Furthermore, the system achieved an impressive 93% efficiency under variable load conditions. The modular nature of the converter makes it not only suitable for EV applications but also for a broader range of industries, including renewable energy systems and industrial power supplies. This paper concludes by discussing optimization strategies for future improvements and potential scaling of the technology for commercial use in sustainable energy applications.

High-current decoupled hydrogen and oxygen evolution via nickel–cobalt based redox mediators and bifunctional catalyst of 3D printing substrates

The conversion of renewable energy sources with relatively large energy fluctuations into hydrogen represents a crucial aspect of energy storage. Nevertheless, the direct water electrolysis process is known to require excessive instantaneous energy consumption and high cost. Two-step alkaline water electrolysis is regarded as a secure and effective method of generating hydrogen from renewable energy sources when compared to direct water electrolysis. Here we propose a two-step alkaline water electrolysis using nickel–cobalt based hydroxide (Ni0.9Co0.1(OH)2) as a redox mediator, and a high-performance bifunctional catalyst as gas evolution electrodes (GEE). The substrates for the GEE were prepared using 3D printing and then loaded with in-situ grown Ru-doped MoS2/NiFe-LDH hierarchical heterostructure catalysts (MS-NiFe-Ru-3D). The oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) of the MS-NiFe-Ru-3D catalyst can reach up to 500 mA cm−2 at 300 and 250 mV overpotentials, respectively. It can meet the requirement of high catalyst performance for two-step alkaline water electrolysis. The direct water electrolysis using the bifunctional MS-NiFe-Ru-3D catalyst only requires a voltage of 1.85 V at 500 mA cm−2 with minimal attenuation over 300 h. For the two-step alkaline water electrolysis using MS-NiFe-Ru-3D as bifunctional catalysts and Ni0.9Co0.1(OH)2 as redox mediator, only 1.70 V and 0.27 V were required for HER and OER at 500 mA cm−2, respectively. This work offers a promising avenue for the efficient conversion of renewable secondary energy sources into hydrogen.

Examination of the Peaceful Uses of Nuclear Energy in Turkish Legislation

Population growth, industrialization and technological advances increase the demand for energy. Due to problems such as global warming, environmental pollution and destruction, the trend towards alternative energy sources continues on a global scale. For this reason, the use of nuclear energy, one of the secondary energy sources, has tended to increase in recent years. Reasons such as the geographically uneven geographical distribution of resources that are raw materials for energy among countries and their exhaustibility, fluctuations in energy prices and the economical production of nuclear energy are among the reasons why countries in the world turn to nuclear energy. A number of accidents at nuclear power plants have had a negative impact on the perception of nuclear power plants, but for different reasons, nuclear energy is gaining popularity again. Nuclear power plants are the first thing that comes to mind when it comes to nuclear power, but it is also used effectively in medical treatments and applications of various branches of science as well as energy production. In global energy production; the fact that it aims to reduce carbon emissions by providing more energy production within the scope of sustainability, the continuous and uninterrupted continuation of electricity production using nuclear, the production of electricity at more affordable costs in nuclear power plants compared to other power plants (thermal, renewable, etc.), the fact that greenhouse gas emissions are almost negligible, and the use of nuclear technology in many fields such as physics, medicine, transportation, agriculture as well as energy production have made nuclear energy back on the agenda of countries in recent years. In nuclear energy, nuclear waste and their storage processes continue to be discussed as a problem in this process. For these reasons, the possibility of peaceful use of nuclear power has been questioned in academic platforms and various criteria have been determined This article examines Turkey's compliance with the criteria for the peaceful use of nuclear energy and clarifies the development process in this regard. Turkey's legislation on nuclear energy, international conventions, nuclear safety, radiation control criteria and compliance with national legislation will be examined.

Prediction of hydrogen consumption scale and hydrogen price based on LEAP model and two-factor learning curve

Under the dual-carbon target, hydrogen energy, as a zero-carbon secondary energy source, has great scope for replacing fossil feedstocks in the fields of energy, transportation and industry. However, the current research on the competitiveness of hydrogen energy in various fields is not sufficiently addressed. In this paper, we use the LEAP model to predict the future scale of hydrogen use and the two-factor learning curve to predict the trend of hydrogen price change from 2025 to 2050, using Qinghai Province as the research background. At the same time, considering the carbon emission reduction benefits and raw material costs, the competitiveness of hydrogen energy in energy, transportation, industry and other fields in the future is compared. The results show that: 1) The hydrogen load scale in Qinghai Province will grow fast from 2025 to 2030. From 2030 to 2040, it slows under the steady and basic scenarios but remains high under the accelerated one. By 2040, the consumption scales are 1.057 million, 649,000 and 442,000 tons respectively. 2) The price of hydrogen energy will drop rapidly from the current 28 CNY/kg to about 20 CNY/kg in the next 5 years. By 2040, the price of hydrogen energy will be reduced to about 17 CNY/kg. 3) In terms of hydrogen energy competitiveness, when carbon emissions are not taken into account, hydrogen energy is currently competitive in the transportation field. During 2032–2038, it will be competitive in the field of methanol synthesis. By 2040, hydrogen energy will not be competitive in the fields of ammonia synthesis and power/heating. When considering carbon emissions, the competitiveness of hydrogen energy in the transportation field will become greater. The competitive year in the field of methanol synthesis will be 1–2 years ahead. By 2040, it will not be competitive in the field of synthetic ammonia and power/heating, but the gap will be significantly reduced due to the consideration of carbon emissions.

Estimation of wood biomass boiler use in cold climate regions on CO2 emissions of light-frame timber structure

Considering Nagano City, as the cold climate region of Japan, the annual heating load was simulated using a model of a two-story timber structure. The results of simulations were used to compare the CO2 emissions according to the energy consumption of five methods of heating as well as primary and secondary energy sources. Actual data from power and gas companies in Nagano and Japanese energy standards were used for the estimations of CO2 emissions of electric heat pump air conditioners, LNG-powered city gas boilers, LPG boilers, kerosene stoves, and wood biomass boilers using pellets as an energy source. Wood biomass boilers showed CO2 emission savings of up to 85 %, 75 %, 75 %, and 76 %, respectively. The operating and equipment costs were estimated based on secondary energy calculations. The kerosene stove had the lowest cost, but CO2 emissions were lowest in the case of using pellet boilers for 30 years. These results clearly show the potential and merit of pellets used in wood biomass boilers as a renewable energy source when compared to fossil fuels. In addition to the CO2 reduction capabilities, the low operating costs of wood biomass heating systems incentivize their use in cold climates.

Comparative analysis of hydrogen production, accumulation, distribution, and storage systems

The global energy demand in the world continues to grow and environmental pollution caused by fossil fuels becomes increasingly serious, the development and utilization of new energy sources has become a hot topic of global concern. The development and utilization of new energy sources is one such possible solution, which can provide clean, renewable energy and thus reduce the impact on the environment. Hydrogen, as a clean, productive, carbon-free secondary energy source, has the potential to be used as a fuel and essential substance for different fields such as heating, transportation, industry, and power generation. As the international community strives to achieve a shift toward a more eco-conscious and sustainable future, hydrogen has received extensive research and attention due to its abundant resources and environmentally friendly properties. The main objective of this study was to describe and comparatively analyze the efficient production, accumulation, distribution and storage of hydrogen. Today the production of hydrogen is centered on the creation or extraction of hydrogen from primary energy sources. The accumulation of hydrogen involves the preservation of surplus hydrogen for subsequent utilization. The distribution of hydrogen encompasses the conveyance and delivery of hydrogen. The storage systems for hydrogen pertain to the technologies and infrastructure employed to retain hydrogen for future deployment. In complex, these constituents establish a comprehensive hydrogen value chain that facilitates the generation, preservation, and distribution of hydrogen as a sustainable and environmentally friendly energy solution. Keywords: comparative analysis, hydrogen, production, accumulation, distribution, storage systems.

Primary and secondary source of energy in the superluminous supernova 2018ibb

We examined a possible pair-instability origin for the superluminous supernova 2018ibb. As the base model, we used a non-rotating stellar model with an initial mass of 250 at about 1/15 solar metallicity. We considered three versions of the model as input for radiative transfer simulations done with the stella and artis codes: with 25 of 56Ni, with 34 of 56Ni, and a chemically mixed case with 34 of 56Ni. We present light curves and spectra in comparison to the observed data of SN\,2018ibb, and conclude that the pair-instability supernova model with 34 of 56Ni explains the broadband light curves reasonably well between $-100$ and 250 days around the peak. Our synthetic spectra have many similarities with the observed spectra. The luminosity excess in the light curves and the blue-flux excess in the spectra can be explained by an additional energy source, which may be an interaction of the supernova ejecta with circumstellar matter. We discuss possible mechanisms that could have caused the circumstellar matter to be ejected in the decades before the pair-instability explosion.

Dehydration and Environmentally Friendly Thermal Processing of Excess Activated Sludge

Introduction. Currently, there is a problem with the accumulation of large amounts of production waste. One type of this waste is excess activated sludge, which is a waste product from biological wastewater treatment that has a high moisture content. When excess activated sludge is deposited in beds, problems can arise related to changes in the gas-air environment, the release of unpleasant odors, as well as the contamination of groundwater and soil. Prolonged presence of sediment in sludge beds in oxygen-free conditions leads to its decay and deterioration of moisture-yielding properties. For these reasons, the development of new methods for disposing of large volumes of waste generated during wastewater treatment is essential. The aim of this research is to develop a technique for preliminary neutralization and thermal treatment of excess activated sludge using energy waste. Materials and Methods. The work used excess activated sludge with a moisture content of 98.2% (waste of hazard class IV). Water treatment sludge (waste of hazard class V) was used as a reagent to increase moisture yield. For experimental studies on dehydration, a laboratory centrifuge Elmi CM-6M.01 was used. Tests were conducted under various conditions (500, 1 000, and 1 500 revolutions per second for 1, 2, and 3 minutes), and the value of centrifugation was determined as a criterion for moisture yield in the sludge. Fuel pellets were produced by rolling with technical lignosulfonate as a binding agent. Elemental analysis of the samples was conducted to study the possibility of thermal treatment using an EA 3 000 Euro Vector Analyzer. Results. A comprehensive technology has been developed to clean the resulting gas emissions from solid particles formed during the combustion of fuel pellets and remove them from the furnace in the form of fly ash along with the outgoing gases. This technology also removed sulfur oxides, nitrogen oxides, and polychlorinated dibenzodioxins and dibenzofurans, while beneficially utilizing flue gas heat by reducing its temperature from 900–1 200°C to 140°C. Discussion and Conclusion. The approach proposed in this article for the processing and disposal of large volumes of waste allows for the reduction of moisture content of excess activated sludge and the use of this waste as a secondary energy source. This method is environmentally friendly and addresses both technical and environmental challenges, such as the effective recycling of industrial waste and reducing the anthropogenic impact on soil, air, and groundwater. It also provides an opportunity to generate additional electrical and thermal energy through thermal utilization of waste. The results of this work indicate that it is possible to integrate the use of various types of industrial waste (sewage sludge, water treatment waste, and pulp and paper industry waste) as secondary energy sources. These findings have practical implications for enterprises in both the municipal and industrial sectors with wastewater treatment facilities.

Qualitative performance improvement of a hybrid power supply at the DC common coupling point using a neuro-fuzzy method

Continuity of power supply service in production industries is of crucial importance, given the severity imposed in these sectors. A poor power supply leads to underproduction or degradation of equipment sensitive to electrical variations. A direct consequence of this is loss of earnings for industry. To ensure continuity of service for industrial power supplies, at least one secondary power source must be available. However, the switching system between sources may not be spontaneous due to the presence of electromechanical switches. The solution to this problem is to use electronic converters for control. The aim of this work is to enhance the parameters of an industrial photovoltaic-grid hybrid power supply to ensure uninterrupted power supply and balance between energy supply and demand. The sources are coupled to the DC bus via electronic converters. The photovoltaic system and the inverter are assumed to be unknown, and only the load terminal voltage is accessible and measurable. To address the lack of mathematical model of the system, we propose a mechanism that combines a fuzzy logic (FLC) centred mechanism with a radial basis function (RBF) neural network for the studied case. The FLC self-determines the image of the compensation power to be extracted through the current to the secondary energy source, ensuring continuity of service and balance between supply and demand. The FLC mechanism self-adjust the parameters of the RBF neural network and coordinates the energy at the DC link. The results obtained in the Matlab/Simulink environment are compared with the fuzzy logic and proportional integral (PI) control method. The quality of the results show that the proposed method is excellent compared with FLC and PI control. It improves response time between 24.223% and 82.9% for PI and between 22.292% and 63.694% for FLC. It guarantees an improvement in the mean square error on PI of between 5.865% and 57.994%, and on FLC of between 1.582% and 29.683%. The proposed method guarantees a high rationing coefficient, helping to maintain the balance between supply and demand, ensure continuity of service for the power supply, and improve the accuracy and self-compensation of the energy to be supplied, both qualitatively and quantitatively.

Digestate and woodchips gasification: A comparison of different gasifying agents

Digestate is the secondary product of the fermentation process in biogas plants. The use of digestate as a fertilizer is very common. However, this is more and more limited nowadays and therefore alternative uses for digestate are sought. The research described in this article maps the possibilities of using digestate from the wet fermentation process for the syngas generation. This work is focuses on the gasification of the digestate with spruce chips mixtures. The mixtures were prepared with a proportion of 0, 25, 50, 75 and 100% of the digestate. The experiments were carried out on a semi-operational fluidized bed gasifier at atmospheric pressure. The working temperature of the fluidized bed was 810 °C; the gasification was autothermal. The gasification was carried out with three types of gasification agents, i.e. air, air-steam, and oxygen-steam for each fuel mixture. The aim of the research was to assess the effect of the digestate with wood chips on the qualitative and quantitative properties of the syngas. The digestate can be characterized as a secondary energy source reducing the consumption of primary energy sources. The produced syngas is of high quality and the digestate can become a very desirable fuel for the syngas production.

Storm-driven hydrological, seasonal, and land use/land cover impact on dissolved organic matter dynamics in a mid-Atlantic, USA coastal plain river system characterized by 21 T FT-ICR mass spectrometry

Introduction: Dissolved organic matter (DOM) as primary and secondary energy sources can be transported via rivers to estuaries and impact coastal biogeochemical cycles. Storm-induced high discharge events can alter the dominant river flow paths and enhance leaching of shallow organic-rich soil layers, leading to elevated terrestrial DOM export. Land use/land cover (LULC) and associated anthropogenic interventions (including artificial reservoirs and agricultural irrigation) can control sources and transformation processes of exported DOM along with hydrologic factors. The relative significance of LULC, hydrological factors, and temperature variations with seasons will differ depending on geographical locations and complicate their incorporation in biogeochemical models of DOM dynamics. This study investigates the role of LULC, seasonality, and storm events on DOM concentrations and molecular composition in the Murderkill River system.Method: Surface water samples were collected seasonally and before/after storm events from 6 sites representing forested, agricultural, and developed LULC units. The DOM was characterized via parallel factor analysis of excitation-emission matrix data and electrospray ionization 21 T Fourier-transform ion cyclotron resonance mass spectrometry to determine potential DOM sources and enable the development of a conceptual model for DOM dynamics in rivers impacted by anthropogenic reservoirs.Result and Discussion: Our results suggest that storm-induced shallow and overland flow paths can increase surface-vegetation/plant-litter derived DOM based on atomic ratios associated with specific biogenic precursors (i.e., lignin, tannins, and/or oxygenated aromatic DOM), particularly in winter when autochthonous production was suppressed due to reduced temperatures. We further demonstrate that the damming effects of artificial reservoirs enhance the role of seasonal patterns of autochthonous production, disrupting storm-shunt process and stimulating significantly more bio-produced DOM export during spring and summer (i.e., tryptophan/tyrosine-like. N- and S- containing, phytoplankton-derived compounds). Collectively, these results demonstrate how artificial reservoirs alter the characteristics of DOM exported from rivers with implications for understanding carbon export and fate at river-estuary interfaces.

Physical mixing of K2CO3/Al2O3 and poly(divinylbenzene) to promote COS removal from blast furnace gas with high humidity at low temperature

Blast furnace gas (BFG) is a high emission and widely used secondary energy source. However, the presence of sulfide in BFG leads to environment pollution. Carbonyl sulfide (COS) is the main (70 %) sulfide in BFG. Catalytic hydrolysis is an important method for COS removal, but the excessive water contained in BFG can significantly inhibit the performance of hydrolysis catalyst. In present work, K2CO3 was loaded on Al2O3 support using wet impregnation method to improve its hydrolysis efficiency. Moreover, a physical mixing method was employed to combine K2CO3/Al2O3 with hydrophobic poly(divinylbenzene) (PDVB) to improve the water resistance of K2CO3/Al2O3. It was found that a simple physical mixture of PDVB with K2CO3/Al2O3 could modulate the local environment of K2CO3/Al2O3, shifting the water-sorption equilibrium on the surface of the catalyst and releasing partial water-covered catalyst surface for hydrolysis. Under the reaction temperature of 90 °C and water vapor content of 34.4 g/m3, the hydrolysis efficiency of COS increased by ∼22.5 % via mixing K2CO3/Al2O3 with PDVB. This approach demonstrates the potential to enhance the hydrolysis efficiency of catalyst for COS removal from BFG with high humidity at low temperature, which is crucial for the practical application of desulfurization of BFG.

Micronutrient intake in the martial arts community: Preparation for national sports

Study Purpose. The provision of protein is related to the intake of calorie reserves and is useful in repairing body cells. Therefore, the provision of protein for the body needs to be considered, especially for athletes. Protein intake can minimize calorie debt and immediately replace damaged cells caused by hard and overused training done by athletes. This study aims to determine the availability of protein intake in martial arts athletes in West Kalimantan Materials and Methods. The research method used was a survey with a sample of nine martial arts athletes in West Kalimantan. The instrument used in this study was a 24-hour food recall for 7 days. Data obtained through food recall were then analyzed using a food analysis application. The data analysis used in this research is descriptive statistics. Results. The results showed that 22.22% of low protein intake athletes and, 33.33% of high protein intake athletes, only 44.44% had moderate protein intake. These results prove that the protein intake of martial arts athletes in West Kalimantan is predominantly moderate. Conclusions. Fulfillment of balanced protein intake will help muscle adaptation, excess and deficiency of protein can interfere with the health and performance of athletes. Therefore, protein intake must be carefully considered, even though protein serves as a secondary energy source where the presence of protein in the body must remain and be fulfilled.

Energy, exergy and economic investigation of novel hybrid dryer, indirect solar dryer and traditional shade drying

By integrating a secondary energy source into solar dryers, more moisture can be removed from food products in the same time period. For this purpose, tomato slices of different thicknesses (7 mm, 15 mm and quarter size) were dried to see the drying, energy, exergy and economic performance of an innovative hybrid dryer consisting of an indirect solar dryer and geothermal heat exchanger unit. The hybrid dryer’s performance was compared simultaneously with indirect solar dryer and traditional shade drying. The analyzes were evaluated according to the feeding of drying air from the solar air collector and geothermal heat exchanger unit. Compared to the other two dryers, the hybrid dryer dried the 7 mm, 15 mm and quarter size samples in the earliest time, with an average of 1380, 2476.3 and 2397.3 min, respectively. The average highest specific moisture extraction rate (0.87 kg/kWh) and dryer efficiency (45.25 %) and the lowest specific energy consumption (4.75 kWh/kg) for hybrid dryer were obtained for the 15 mm. The highest exergy efficiency for the solar air collector and drying chamber of the hybrid dryer was determined at 7 mm with 3.08 % and 38.9 %, respectively. The lowest payback period for the hybrid dryer was found to be 0.37 years for 7 mm. The results showed that the hybrid dryer was superior to the other two dryers by drying continuously day and night. Hybrid dryer can create a successful commercial ecosystem as an important drying alternative for locations where geothermal energy is available.

Study on life-cycle carbon emission factors of electricity in China

Abstract As China’s largest carbon-emitting sector, the power sector has been the subject of extensive attention from relevant scholars and organizations. As China’s most widely used secondary energy source, greenhouse gas (GHG) emissions from electricity often account for a significant share of total corporate or product carbon emissions. In this study, we calculated the life-cycle carbon emission factors of China’s electric power based on the ISO 14067 and PAS 2050 standards and the current development of China’s power generation industry in recent years. This study makes a preliminary prediction of China’s electricity life-cycle carbon emission factors in 2025 and 2030. The results show that the life-cycle carbon emission factors of China’s thermal, solar, hydro, wind, and nuclear power generation are 0.9976 ${\textsf{tCO}}_2\textsf{e}/\textsf{MWh}$, 0.0142 ${\textsf{tCO}}_2\textsf{e}/\textsf{MWh}$, 0.0188 ${\textsf{tCO}}_2\textsf{e}/\textsf{MWh}$, 0.0100 ${\textsf{tCO}}_2\textsf{e}/\textsf{MWh}$, and 0.0122 ${\textsf{tCO}}_2\textsf{e}/\textsf{MWh}$, respectively, and ultimately obtain the life-cycle carbon emission factors for China’s comprehensive electricity footprint is 0.6835 ${\textsf{tCO}}_2\textsf{e}/\textsf{MWh}$. Thermal power generation has a much larger carbon emission factors than other power generation modes, tens to nearly a hundred times larger than other power generation modes and contributes more than 90% of the carbon emission factors of China’s comprehensive electricity footprint; among the remaining modes of power generation, wind power generation have relatively small carbon emission factors. The predicted carbon emission factors for China’s electric power in 2025 and 2030 are 0.6144 ${\textsf{tCO}}_2\textsf{e}/\textsf{MWh}$ and 0.5154 ${\textsf{tCO}}_2\textsf{e}/\textsf{MWh}$, respectively. This study improves the accuracy of accounting for product carbon emission factors and provides data references to peer organizations, enterprises, and the government to carry out product carbon emission factors accounting.

Challenges and Future Perspectives on Production, Storage Technologies, and Transportation of Hydrogen: A Review

Hydrogen plays an essential role in the energy‐transition process. Even though currently almost 80–96% of hydrogen is produced from fossil fuel sources in the world, the exciting feature of hydrogen is that it can be produced from renewable sources by splitting water molecules through electrolyzing, and then it can be re‐electrified without any emissions by‐products. Hydrogen is the secondary source of energy as well as an energy carrier that stores and transports the energy produced from other sources such as water, biomass, and fossil fuels. It is a clean‐burning fuel; when oxidized in a fuel cell, it produces heat, electricity, and water vapor as a by‐product, without any carbon emissions. Despite these exciting characteristics of hydrogen, there are still a variety of challenges, such as cost‐effective hydrogen production and its technological challenges, storage, safety, transportation, and cost issues. This article aims to overview the challenges and opportunities in hydrogen production, storage, and transportation along with some future perspectives on hydrogen.

Recent strategies for improving the catalytic activity of ultrathin transition metal sulfide nanosheets toward the oxygen evolution reaction

Hydrogen is considered as one of the clean secondary energy sources required in industry and daily life. Electrocatalytic hydrogen production is believed to be the most reliable method for converting renewable energy into chemical energy. Two-dimensional (2D) transition metal disulfides (TMDs), as an emerging electrocatalysts, have been widely investigated for oxygen evolution reaction (OER) in water splitting. Herein, this review summarizes the recent progress and the strategies of ultrathin TMDs for improving the OER electrocatalytic activities. The basic catalytic mechanism of OER is first introduced, and then the catalytic characteristics of 2D TMDs are presented. Importantly, this review specifically concentrates on strategies to improve catalytic activity such as phase engineering, defect/vacancy engineering, heterostructure, doping effect, and catalyst support material. It can be concluded that these regulatory strategies can largely enhance the electrocatalytic performance by increasing the active site exposure and improving the electrocatalytic kinetics. In addition, the challenges and perspectives of 2D TMDs catalysts are presented, which offers valuable guidance in designing efficient and low-cost OER electrocatalysts for future energy applications. We hope that this review will inspire future studies and bridge the gap between strategy design and practical application.

МАТЕМАТИЧНА МОДЕЛЬ ПРОГНОЗУВАННЯ ОБСЯГІВ УТВОРЕННЯ ВЖИВАНОЇ ДЕРЕВИНИ

It is substantiated that a potential source of wood raw materials is various wood waste, in particular, post-consumer wood (PCW). A detailed review and thorough analysis was made to determine the principles of PCW classification at the Ukrainian level. The classification of PCW by degree of pollution into four groups is proposed. A method of calculating the used wood has been developed, which makes it possible to calculate its quantity effectively and reliably. A mathematical model for calculating the potential and balance of PCW by origin is proposed. It was established that the weighted average annual percentage of PCW from the trade network ranges from 14-16%, construction - 20-24%, raw materials and woodworking industries - 6-10%, used (old) furniture products - 10-16%, municipal waste - 16-18%, solid waste – 16-22%, other revenues – 6-8%. On the basis of statistical data from 2015 to 2023, approximating power dependences for each total indicator were obtained, which make it possible to forecast the volume of PCW formation in the near future, in particular until 2024. The implementation of the developed mathematical model makes it possible to effectively forecast the distribution of PCW by categories that determine the degree of pollution and, accordingly, the percentage of material processing of PCW. It is estimated that the potential of PCW in Ukraine in 2023 was about 1.783 million tons. It is justified that the improvement of PCW management at all levels should be based on general technical, economic and environmental standards and focus on the following proposals: analysis of PCW management; calculation of the potential of PCW as a secondary raw material and energy source; improvement of databases on technical, economic, environmental and statistical information; implementation of new approaches to PCW management, taking into account already existing schemes. A strategy for the material use of PCW was developed, which is based on the assessment of potential volumes of PCW according to a mathematical model, systematization of PCW by categories, classification by pollution, the concept of utilization of PCW by processing into dimensionally suitable blanks and construction materials, in particular, carpentry plates of various structures with predicted characteristics, which take into account the physical and mechanical properties of this additional wood resource.

Estimation of the hourly solar radiation

Hybrid facility investments from renewable energy sources have increased in recent years. In general, solar power is the secondary energy source in hybrid systems. The reason why solar energy is most commonly used in hybrid power systems is that it is cheaper than other types of renewable energy. Solar-Hydroelectric (SHE) is one of the foremost compatible hybrid energy pairs, as solar and hydroelectric power generation profiles complement one another. Hybrid systems consisting of solar and hydropower have complementary characteristics due to the shared use of infrastructure systems and different periodicities in power generation. Energy management is important for SHE-integrated facilities. Since only a limited amount of energy can be injected into the grid from transformer capacities, energy management in hybrid systems is of great importance. To manage energy in hybrid energy systems, the amount of energy that can be produced each hour must be determined. In hybrid energy plants, there is usually already another renewable energy plant in place, and solar energy is added on top and optimized. Since there are no pyrometers in the existing plants, the daily radiation data from the National Aeronautics and Space Administration (NASA) is used, but the daily energy production amount may be insufficient for accurate energy management. To realize this, it’s necessary to reveal the energy generation on an hourly basis. During this study, the quantity of radiation on an hourly basis was determined to calculate solar power generation. Empirical and econometric models utilized in radiation amount determination were performed, and the most appropriate method was clarified by comparing them with one another. Hourly-based radiation is achieved with an empirical method by using National Aeronautics and Space Administration (NASA) daily radiation.

Evaluation of energy management system of a hybrid energy source in EV

<span lang="EN-US">This paper presents a comparative study of different energy management strategies and technologies of fuel-cell hybrid electric vehicles integrating a proton exchange membrane fuel cell device in addition to a lithium-ion battery as a secondary energy source. Therefore, an experimental analysis is carried out to seek the successful hybrid powertrains considering the hydrogen utilization in fuel cells and state-of-charge regulation in Li-ion batteries. Different approaches were simulated using a developed vehicle simulator in MATLAB/Simulink. The simulations were performed using three standard driving cycles in which a second study based on energy management strategies tested was presented and analyzed. Simulation’s results show the superiority and economic success of the proposed technology and method, especially the FSBS and MEPT management strategies due to the successful use of the sources and the significant optimization in terms of hydrogen consumption while maintaining optimal Li-ion battery usage.</span>