Search Results (10,142)

Surface solar irradiance (SSI) is a critical factor influencing the power generation capacity of photovoltaic (PV) power plants. Dynamic changes in cloud cover pose significant challenges to the accurate nowcasting of SSI, which in turn directly affects the reliability and stability of renewable energy systems. However, existing research often simplifies or overlooks changes in the optical and morphological characteristics of clouds, leading to considerable errors in SSI nowcasting. To address this limitation and improve the accuracy of ultra-short-term SSI forecasting, this study first forecasts changes in cloud optical thickness (COT) within the next 3 h based on a spatiotemporal long short-term memory model, since COT is the primary factor determining cloud shading effects, and then integrates the zenith and regional averages of COT, along with factors influencing direct solar radiation and scattered radiation, to achieve precise SSI nowcasting. To validate the proposed method, we apply it to the Albuquerque, New Mexico, United States (ABQ) site, where it yielded promising performance, with correlations between predicted and actual surface solar irradiance for the next 1 h, 2 h, and 3 h reaching 0.94, 0.92, and 0.92, respectively. The proposed method effectively captures the temporal trends and spatial patterns of cloud changes, avoiding simplifications of cloud movement trends or interference from non-cloud factors, thus providing a basis for power adjustments in solar power plants. Full article

The political commitment to reaching carbon-free energy generation by the year 2050 has led to an increased expansion of renewable energy power plants. As renewable energy generation is intermittent and current energy storage options are limited, a diversified energy grid including nuclear power is the preferable choice for most nations. Many innovative reactor concepts are being pursued in research and development, aiming to supplement fluctuating energy sources. However, it is yet unclear if these technologies can be economically deployed in time. This paper presents the current political views and events concerning the global expansion of nuclear energy, focusing on Europe and the USA. Further, the most important safety aspects of large nuclear power plants are discussed. Moreover, knowledge and definition gaps regarding the applicability of established procedures for innovative reactor concepts are included. The authors highlight that advanced manufacturing techniques play a key role in the economic and technical realization of innovative reactor concepts. The present work is intended to provide insight into current developments in nuclear technology while providing more detail on safety aspects and innovative manufacturing methods. Full article

The Ile River is the main water artery of the Lake Balkhash basin and the main fresh water resource supplying the south-eastern part of Kazakhstan. Increasing human economic activity makes it necessary to assess the anthropogenic load of the river on various ecosystems, including possible harmful effects. The assessment of anthropogenic load on the Ile River ecosystem was realized by the anthropogenic load fraction indicator and by the values of the chemical substance inflow modulus. For this purpose, the Ile River was divided into 3 sections: section I—from the border post HP Dobyn to 164 km above Kapshagai hydroelectric power plant (HPP); section II—between the points 164 km above and 37 km below Kapshagai HPP; and section III —from 37 km below HPP to Ushzharma village. The anthropogenic load strongly depends on the share of anthropogenic impact contributed by pollutants. Characteristic pollution components are copper, and in some cases zinc, ammonium, and nitrite nitrogen. The assessment of anthropogenic load also considers organic and biogenic substances in the chemical composition of river water. The variability in the volume of dissolved chemical inflows in different sections of the river made it possible to assess the transformation of anthropogenic load along the length of the Ile River. Full article

Driven by the “dual carbon” goal, virtual power plants (VPPs) are the core vehicle for integrating distributed energy resources, but the multiple uncertainties in wind power, electricity/heat load, and electricity price, coupled with the impact of carbon-trading cost, make it difficult for traditional scheduling methods to balance the robustness and economy of VPPs. Therefore, this paper proposes an oxy-fuel combustion capture (OCC)-VPP architecture, integrating an OCC unit to improve the energy efficiency of the system through the “electricity-oxygen-carbon” cycle. Ten typical scenarios are generated by Latin hypercube sampling and K-means clustering to describe the uncertainties of source and load probability distribution, combined with the polyhedral uncertainty set to delineate the boundary of source and load fluctuations, and the stepped carbon-trading mechanism is introduced to quantify the cost of carbon emission. Then, a three-stage stochastic–robust scheduling model is constructed. The simulation based on the arithmetic example of OCC-VPP in North China shows that (1) OCC-VPP significantly improves the economy through the synergy of electric–hydrogen production and methanation (52% of hydrogen is supplied with heat and 41% is methanated), and the cost of carbon sequestration increases with the prediction error, but the carbon benefit of stepped carbon trading is stabilized at the base price of 320 DKK/ton; (2) when the uncertainty is increased from 0 to 18, the total cost rises by 45%, and the cost of purchased gas increases by the largest amount, and the cost of energy abandonment increases only by 299.6 DKK, which highlights the smoothing effect of energy storage; (3) the proposed model improves the solution speed by 70% compared with stochastic optimization, and reduces cost by 4.0% compared with robust optimization, which balances economy and robustness efficiently. Full article

The soil nitrification rate is significantly affected by plant species, and it is also modulated by different nitrogen levels in the soil. There are a wide range of plant species with the capacity to produce biological nitrification inhibitors (hereafter referred to as BNI species). The preliminary results of this study report the influence of three different plant species on the nitrification rates under soil supply with three (0 mM, 3.5 mM, and 7.0 mM) nitrogen levels. The aim was to evaluate the potential of hemp, ryegrass, and sorghum in mitigating nitrification, in order to define a sustainable strategy for improving the nitrogen use efficiency by crops and to limit the nitrogen loss from agroecosystems. Leaf gas exchange measurements were also carried out in this study. Photosynthesis was only affected by nitrogen supply in hemp, resulting in a reduction in CO₂ assimilation at nitrogen doses higher than the plant’s requirements. Ryegrass devotes more reductive power towards leaf nitrogen assimilation than sorghum and hemp do. The greatest variation in nitrification rate in response to N was observed in soil cultivated with hemp (which also showed the highest potential nitrification rate), followed by sorghum and ryegrass. We speculate that this occurred because the greater seed sowing density for ryegrass ensured a greater quantity in the soil of molecules acting on nitrification compared to sorghum and hemp, with these latter being sown at lower densities. Our results suggest that sorghum and ryegrass might directly affect nitrification by BNI molecules, whereas hemp might indirectly mitigate nitrification through the nitrogen uptake. However, further research is needed to evaluate the effects exerted by the studied plant species on nitrification rates. Full article

Currently, wind turbines utilize doubly fed induction machines that incorporate a frequency converter in the rotor circuit to manage slip energy. This setup ensures a stable voltage amplitude and frequency that align with the alternating current. It is crucial to accurately determine the parameters of the equivalent circuit from the rotor side of the vector control system of the frequency converter. The objective of this study is to develop a method for the preliminary identification of the doubly fed induction machines parameters by analyzing the rotor current decay curves using Newton’s method. The numerical estimates of the equivalent circuit parameters a doubly fed induction machines with a fixed short-circuited rotor are obtained during the validation of the results on a real plant. It is along with the integral errors of deviation between the experimental rotor current decay curve and the response of the adaptive regression model. The integral errors do not exceed 4% in nearly all sections of the curves. It is considered acceptable in engineering practice. The developed algorithm for the preliminary identification for the parameters of the doubly fed induction machines substitution scheme can be applied with the configuring machines control systems, including a vector control system. Full article

Accurate temperature control across different zones during the combustion and heat exchange stages is crucial for both the economic efficiency of municipal solid waste incineration (MSWI) power plants and the consistent achievement of environmental targets. To address limitations in existing research, such as single-point temperature prediction models and the difficulty in characterizing the correlation mapping between adjacent zones, this article proposes a multi-point serial temperature prediction modeling method for the combustion and heat exchange stages of the MSWI process. Firstly, based on identifying five key temperature points across different zones in these stages, the Pearson correlation coefficient (PCC) is utilized for regional feature selection targeting each individual temperature point. Subsequently, multiple single temperature point prediction models based on a linear regression decision tree (LRDT) are constructed using the selected feature variables. Finally, considering the mutual influence between temperatures in neighboring zones, a serial multi-point temperature prediction model is built by using the knowledge transfer. To our knowledge, this is the first interpretable multi-point temperature prediction model for the MSWI process. It can assist in precise temperature control across different zones during the combustion and heat exchange stages in future studies. Validation results demonstrate that the minimum MSE attained 0.0238, the minimum MAE reached 0.1223, and the maximum R² achieved 0.9985 across multiple temperature points. The proposed method is validated using actual operational data from an MSWI power plant in Beijing. Full article

This review article examines the corrosion phenomena and mitigation strategies associated with molten salts used in thermal energy storage (TES) and heat transfer applications. Corrosion presents a critical challenge in concentrated solar power (CSP) plants and other high-temperature systems, affecting the durability and cost-efficiency of materials in storage tanks, heat exchangers, and piping. This study offers a comprehensive comparison of corrosion test methods and results, analyzing factors such as operating conditions, salt compositions, and material properties. Emphasis is also placed on strategies such as molten salt purification, the addition of corrosion inhibitors, and the application of protective coatings. This review aims to advance research and development in the TES sector by highlighting knowledge gaps and proposing directions for future experimentation. Full article

Amid rising load volatility and uncertainty, demand-side resources with regulation capabilities are increasingly engaged at scale in ancillary service markets, facilitating sustainable peak load mitigation and alleviating grid stress while reducing reliance on carbon-intensive peaking plants. This study examines the integration of electric vehicles (EVs) in peak regulation, proposing a multi-stage operational strategy framework grounded in the analysis of EV power and energy response constraints to promote both economic efficiency and environmental sustainability. The model holistically accounts for temporal charging and discharging behaviors under diverse incentive mechanisms, incorporating user response heterogeneity alongside multi-period market peak regulation demands while supporting clean transportation adoption. An optimization model is formulated to maximize aggregator revenue while enhancing grid sustainability and is solved via MATLAB(2021b) and CPLEX(20.1.0). The simulation outcomes reveal that the discharge-based demand response (DBDR) strategy elevates aggregator revenue by 42.6% and enhances peak regulation margins by 19.2% relative to the conventional charge-based demand response (CBDR). The hybridization of CBDR and DBDR yields a threefold revenue increase and a 28.7% improvement in peak regulation capacity, underscoring the efficacy of a joint-response approach in augmenting economic returns, grid flexibility, and sustainable energy management. Full article

Rapid pressure fluctuations—known as hydraulic transients—occur during valve operations or load changes in turbines and pumps. The presence of biofouling, particularly caused by the golden mussel (Limnoperna fortunei), can intensify these effects and compromise the structural integrity of pressurized systems. This study experimentally evaluated the influence of such biofouling on pressure peaks during transient events in forced conduits. A hydraulic test rig was developed using PVC pipes with nominal diameters of 2½”, 3”, and 4”, tested under both clean conditions and with simulated biofouling printed in 3D, replicating mussel morphology. Results showed that, under the same initial flow rates, pressure peaks in biofouled pipes were significantly higher than in clean ones, especially in smaller diameters. To mitigate structural risks, the downstream shut-off valve closure time was modulated using a needle valve, effectively reducing peak pressures to levels closer to design limits. It is concluded that L. fortunei colonization alters transient hydraulic behavior and should be considered in the design and operation of systems vulnerable to biofouling, particularly in critical infrastructure such as water supply networks and hydroelectric power plants. Full article

Hydrogen-based Power Systems (H2PSs) are gaining accelerating momentum globally to reduce energy costs and dependency on fossil fuels. A H2PS typically comprises three main parts: hydrogen production, storage, and power generation, called packages. A review of the literature and Original Equipment Manufacturers (OEM) datasheets reveals that no single manufacturer supplies all H2PS components, posing significant challenges in system design, parts integration, and safety assurance. Additionally, both the literature and H2PS projects’ database highlight a gap in a systematic hydrogen equipment and auxiliary sub-systems technology selection process, and how this selection affects the overall H2PS Balance of Plant (BoP). This study addresses that gap by providing a guideline for available technology options and their impact on the H2PS-BoP. The analysis compares packages and auxiliary sub-system technologies to support informed engineering decisions regarding technology and equipment selection. The study finds that each package’s technology influences the selection criteria of the other packages and the associated BoP requirements. Furthermore, the choice of technologies across packages significantly affects overall system integrity and BoP. These interdependencies are illustrated using a cause-and-effect matrix. The study’s significance lies in establishing a structured guideline for engineering design and operations, enhancing the accuracy of feasibility studies, and accelerating the global implementation of H2PS. Full article

Opuntia dillenii has gained considerable scientific attention as a potential natural source of antioxidants. This systematic review compiles and evaluates current evidence regarding its antioxidant activity. A PRISMA-guided literature search was conducted using PubMed, Scopus, and Web of Science, identifying 37 eligible studies. These studies employed two main methodological approaches: chemical-based assays and biological models. Chemical assays, including radical scavenging and reducing power assays, demonstrated a broad range of antioxidant activity influenced by factors such as the extraction method, plant part, plant maturity, and geographic origin. Polysaccharides, betalains, and polyphenols were consistently identified as primary contributors to these effects. Biological models further supported the antioxidant properties of O. dillenii extracts. In animal studies, administration of the extracts significantly improved oxidative stress biomarkers, increasing glutathione levels, reducing malondialdehyde concentrations, and enhancing the activity of antioxidant enzymes, particularly in the liver and other digestive tissues like the colon, stomach, and pancreas. Cellular studies using hepatocyte, macrophage, enterocyte, and neuronal cell lines produced comparable results, confirming the antioxidant effects. In conclusion, O. dillenii exhibits promising antioxidant potential across various experimental models. However, the absence of human clinical trials highlights the need for further research to establish its efficacy and safety as a nutraceutical product. Full article

Multi-layer multi-pass welding plays an important role in manufacturing industries such as nuclear power plants, pressure vessel manufacturing, and ship building. However, distortion or welding defects are still challenges; therefore, welding monitoring and quality control are essential tasks for the dynamic adjustment of execution during welding. The aim was to propose a machine vision system for monitoring and surface quality evaluation during multi-pass welding using a line scanner and infrared camera sensors. The cross-section modelling based on the line scanner data enabled the measurement of distortion and dynamic control of the welding plan. Lack of fusion, porosity, and burn-through defects were intentionally generated by controlling welding parameters to construct a defect inspection dataset. To reduce the influence of material surface colour, the proposed normal map approach combined with a deep learning approach was applied for inspecting the surface defects on each layer, achieving a mean average precision of 0.88. In addition to monitoring the temperature of the weld pool, a burn-through defect detection algorithm was introduced to track welding status. The whole system was integrated into a graphical user interface to visualize the welding progress. This work provides a solid foundation for monitoring and potential for the further development of the automatic adaptive welding system in multi-layer multi-pass welding. Full article

The column photobioreactor has become the predominant approach for carbon sequestration by microalgae in power plant settings, owing to its capacity for high-density cultivation and efficient light energy utilization. Due to the dense arrangement of the columnar photobioreactor and its height, insufficient light became one of the main factors limiting the carbon sequestration rate of microalgae growth. In this paper, a light resource optimization method of reflective baffle and top diffusing glass was proposed. When the angle of reflective baffle on the north and east walls was 35°, and the angle of reflective baffle on the west and south floors was 0°, the overall light radiation intensity of the reactor array became the largest, reaching up to 916.81 W/m², which was 14.39% higher than that before the optimization. The replacement of the top glass with diffusing material converted the direct radiation of solar radiation into scattered radiation. When the transmittance was 95% and the haze was 95%, the overall average light radiation intensity of the algal solution reached 830.93 W/m², which was an increase of 3.7%. Four new exhaust air distribution methods were proposed, in which the three-entrance staggered-arrangement type glasshouse had the lowest algal liquid temperature. Full article

Water stress and weed competition emerge as pivotal stressors during the development of corn. This two-year study evaluated the effect of Amaranthus palmeri (AMAPA) on corn at varying densities (1, 2, and 4 plants per m⁻¹) under two different irrigation (full and deficit) regimes. Water use efficiency and leaf water potential values were evaluated to determine the effects of different irrigation water amounts and AMAPA densities on corn water consumption. AMAPA height and fresh weight were also measured along with corn growth parameters. The results indicated that corn height, first ear height and number of rows in corn ear decreased by 14.5%, 22.1% and 9.47% on average with the effect of deficit irrigation compared to full irrigation. Under the pressure of four AMAPA plants, ear diameter, ear length, number of grains in a row of ears, ear weight and grain yield decreased by 10.7%, 22.4%, 26.3%, 43.0% and 43.1% on average compared to monoculture corn. Deficit irrigation increased water use efficiency values, while AMAPA density decreased these values. While this study demonstrated that a reduction in irrigation and an increase in AMAPA density exerted adverse effects on the growth parameters of corn, it was also observed that under deficit irrigation conditions, AMAPA did not demonstrate superiority over corn, which possesses a high degree of competitive power in comparison to other C3 summer crops. Full article