Search Results (109)

The rapid integration of inverter-based renewable energy sources (RES), particularly solar photovoltaic (PV) and wind power plants (WPPs), together with the large-scale deployment of battery energy storage systems (BESSs) is fundamentally reshaping modern power systems. While these technologies are essential for decarbonization, their converter-dominated and variable characteristics introduce new challenges for grid stability, operational security, and regulatory compliance. As a result, grid codes are being continuously revised to define advanced technical requirements, including fault ride-through (FRT) capability, reactive power support, frequency response, voltage control, and active power management for RESs and energy storage systems (ESS). This study presents a systematic comparative assessment of international grid codes, examining the technical and operational requirements imposed on inverter-based resources (IBR) and ESSs across multiple jurisdictions. In parallel, the current Turkish Grid Code is evaluated from a future-oriented perspective, and recommendations that can improve the existing regulatory framework are proposed, particularly regarding high-voltage ride-through capability, synthetic inertia provision, fast frequency response (FFR), hybrid power plant (HPP) coordination, and ESS-specific performance criteria. Based on the comparative analysis, the study proposes targeted amendments to the Turkish Grid Code aimed at enhancing system resilience under high renewable penetration levels. Furthermore, field-testing methodologies, model-based validation practices, and emerging digitalized compliance monitoring architectures are investigated to assess their applicability to next-generation power systems. By integrating international best practices with country-specific recommendations, this work contributes to the development of transparent, adaptive, and technically robust grid code compliance frameworks, supporting both academic research and practical grid modernization efforts. Full article

The study explored the impact of Microwave-Assisted Extraction (MAE) on the physicochemical, structural, functional, and antioxidant properties of protein concentrates from white pea (Lathyrus sativus), red gram (Cajanus cajan), and black gram (Vigna mungo). The objective was to evaluate the efficiency of MAE as a sustainable green extraction technique compared to the conventional method. Total amino acid content increased in MAE protein from 69.23 to 72.78 g/100 g powder in white pea protein (WPP), 69.41 to 72.39 g/100 g powder in red gram protein (RGP), and 65.56 to 70.30 g/100 g powder in black gram protein (BGP). Functionally, MAE significantly improved solubility and emulsifying capacity and water- and oil-holding capacities. Bioactive evaluation showed a significant increase in total phenolic and flavonoid contents, followed by improved DPPH, ABTS, and FRAP activities. A reduction in tannins and phytic acid correlated with enhanced in vitro protein digestibility. These enhanced MAE-derived proteins further demonstrated superior performance when incorporated into wheat flour, improving its nutritional and functional properties. Overall, MAE protein demonstrated improved structural integrity, antioxidant potential, and digestibility, highlighting white pea protein as the most responsive legume to MAE, followed by red and black gram. Full article

This study presents an integrated experimental simulation and multi-objective optimization methodology that maximizes energy production and optimizes economic performance in the design of wind power plants (WPPs). The relationship between five fundamental design parameters (wind speed (XWS), hub height (XHH), rotor diameter (XRD), turbine spacing (XTS), and row spacing (XRS)) and five techno-economic outputs (annual AC energy (YAEP), net present value (YNPV), levelized cost of energy (YLCOE), net cost of capital (YNCCpw), and total BOS cost (YTBC)) is systematically investigated using a Multi-Level Full Factorial Experimental Design (DoE) for four different US regions (Southern Wyoming, Southern California, Northeastern West Virginia, and South Florida). The optimization was performed by applying a multi-objective desirability function to regression models derived from 1200 NREL SAM simulation data points, thereby simultaneously evaluating five design parameters across five techno-economic responses. ANOVA results revealed that 77.5% of the variability in annual energy production was due to wind speed and 21.4% to rotor diameter, clearly demonstrating the decisive role of resource quality in project feasibility. Optimization identified the optimal configuration (XRS = 5, XTS = 3, XWS = 10.157 m/s, XHH = 120 m, XRD = 70 m) that provided a balanced trade-off between conflicting objectives, achieving 575.16 GWh of YAEP, $42.02 million of YNPV, $43.66 million of YTBC, 2.368 cents/kWh of YLCOE, and $1.508/W of YNCCpw. The study emphasizes that resource evaluation precedes technological optimization in the planning phase of wind energy projects, demonstrating that integrating DoE, simulation, and multi-objective optimization provides a strong framework for achieving realistic, feasible, and economically sustainable WPPs. The novelty of this approach lies in its ability to simultaneously account for environmental stochasticity and economic feasibility, providing a robust computational roadmap for stakeholders to maximize energy efficiency while minimizing levelized costs. Full article

Wind power plants (WPPs), as large-scale cyber–physical systems (CPSs), have become essential to renewable energy generation but are increasingly exposed to cyber threats. Attacks on supervisory control and data acquisition (SCADA) networks can cause cascading physical and economic impacts. The systematic synthesis of cyber risk analysis methods specific to WPPs and cyber–physical energy systems (CPESs) is a need of the hour to identify research gaps and guide the development of resilient protection frameworks. This study employs a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol to review the state of the art in this area. Peer-reviewed studies published between January 2010 and January 2025 were taken from four major journals using a structured set of nine search queries. After removing duplicates, applying inclusion and exclusion criteria, and screening titles and abstracts, 62 studies were examined for analysis on the basis of a synthesis framework. The studies were classified along three methodological dimensions, qualitative vs. quantitative, model-based vs. data-driven, and informal vs. formal, giving us a unified taxonomy of cyber risk analysis approaches. Among the included studies, 45% appeared to be qualitative or semi-quantitative frameworks such as STRIDE, DREAD, or MITRE ATT&CK; 35% were classified as quantitative or model-based techniques such as Bayesian networks, Markov decision processes, and Petri nets; and 20% adopted data-driven or hybrid AI/ML methods. Only 28% implemented formal verification, and fewer than 10% explicitly linked cyber vulnerabilities to safety consequences. Key research gaps include limited integration of safety–security interdependencies, scarce operational datasets, and inadequate modelling of environmental factors in WPPs. This systematic review highlights a predominance of qualitative approaches and a shortage of data-driven and formally verified frameworks for WPP cybersecurity. Future research should prioritise hybrid methods that integrate formal modelling, synthetic data generation, and machine learning-based risk prioritisation to enhance resilience and operational safety of renewable-energy infrastructures. Full article

Resveratrol (RES) suffers from low bioavailability and poor gastrointestinal stability, limiting its health benefits. To overcome these challenges, we developed biomimetic mineralized nanoparticles based on walnut protein peptides (WPP-RES@CaP) for intestinal-targeted RES delivery. WPP with a 31.83% degree of hydrolysis was optimal for RES encapsulation. Subsequent mineralization with 5 mM Ca²⁺ significantly enhanced the encapsulation efficiency (EE) to 95.86%, compared to 73.69% for non-mineralized WPP-RES nanoparticles. The particle size and zeta potential of WPP-RES@CaP were 795 ± 16 nm and −27 ± 1 mV, respectively. Beyond the initial hydrophobic and π-π interactions, mineralization introduced additional stabilizing forces, including metal–ligand coordination, salt bridges, and electrostatic interactions, which collectively enhanced the structural integrity and RES retention of WPP-RES@CaP. During in vitro gastrointestinal digestion, the formation of a CaP shell protected RES and WPP from excessive degradation in the gastric phase. The 77.57% RES in WPP-RES@CaP was continuously released in the intestinal phase, which was higher than that of WPP-RES (49.73%). Meanwhile, the introduction of Ca²⁺ promoted the antioxidant activity of WPP-RES@CaP, which demonstrated higher DPPH and ABTS radical-scavenging activity assays than WPP-RES both before and after digestion. It was probably due to the synergistic effect of more released RES, antioxidant-free amino acids, and peptides. This mineralized peptide-based system provided a strategy for improving the delivery of hydrophobic bioactive compounds in functional foods. Full article

With the rapid increase in plastic consumption, waste polypropylene (WPP) has become one of the major components of municipal solid waste, posing significant environmental and resource challenges. According to statistics, polypropylene accounts for approximately 19.1% of the total global plastic waste, posing significant environmental challenges. In recent years, the recycling and reuse of WPP in asphalt pavement materials have received increasing attention due to its excellent mechanical properties, thermal stability, and low cost. This review systematically summarizes the physicochemical properties and recycling technologies of WPP, including mechanical, chemical, and energy recovery routes. Furthermore, the modification mechanisms, preparation methods, and performance characteristics of WPP-modified asphalt binders and mixtures are comprehensively discussed, focusing on their high-temperature stability, compatibility, low-temperature cracking resistance, and anti-moisture damage. Research indicates that WPP modification significantly enhances high-temperature rutting resistance, and thermo-chemical modifiers have successfully enabled the application of WPP in warm-mix asphalt. This review uniquely integrates recent advances in thermo-mechanochemical upcycling with mixture-level performance, bridging molecular design and field application. However, critical challenges, including poor compatibility, insufficient storage stability, and the lack of a unified assessment for the high variability of WPP raw materials, still need to be addressed. Finally, this review primarily focuses on the recycling technologies of WPP, its modification mechanisms in asphalt binders, and the resulting impact on the pavement performance of WPP-modified mixtures. Full article

The rapid integration of wind power plants (WPPs) into modern electrical power systems (MEPSs) is crucial to global decarbonization, but it introduces significant technical challenges. Variability, intermittency, and forecasting uncertainty compromise frequency stability, voltage regulation, and grid reliability, particularly at high levels of renewable energy integration. To address these issues, adaptive control strategies have been proposed at the turbine, plant, and system levels, including reinforcement learning-based optimization, cooperative plant-level dispatch, and hybrid energy schemes with battery energy storage systems (BESS). At the same time, interoperability frameworks based on international standards, notably IEC 61850 and IEC 61400-25, provide the communication backbone for vendor-independent coordination; however, their application remains largely limited to monitoring and protection, rather than holistic adaptive operation. Real-Time Automation Controllers (RTACs) emerge as promising platforms for unifying monitoring, operation, and protection functions, but their deployment in large-scale WPPs remains underexplored. Validation of these frameworks is still dominated by simulation-only studies, while real-time digital simulation (RTDS) and hardware-in-the-loop (HIL) environments have only recently begun to bridge the gap between theory and practice. This review consolidates advances in adaptive control, interoperability, and validation, identifies critical gaps, including limited PCC-level integration, underutilization of IEC standards, and insufficient cyber–physical resilience, and outlines future research directions. Emphasis is placed on holistic adaptive frameworks, IEC–RTAC integration, digital twin–HIL environments, and AI-enabled adaptive methods with embedded cybersecurity. By synthesizing these perspectives, the review highlights pathways toward resilient, secure, and standards-compliant renewable power systems that can support the transition to a low-carbon future. Full article

Background: In the era of longevity, many low- and middle-income countries (LMICs) still lack a comprehensive understanding of health deficits among older adults and the care burden associated with “unhealthy longevity”. This study aims to reveal future changes in care needs and pressure in China from 2030 to 2100. Method: This study develops a multistate demographic forecasting framework by integrating a Markov-based health state transition model with the conceptual logic of an age-shift algorithm. Transition probability matrices by age and gender are estimated using nationally representative microdata from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Baseline population data from the National Bureau of Statistics and WPP 2024 are then used to simulate the evolution of health status among older adults in China from 2030 to 2100. Finally, person-years with disability (PYD) are calculated to evaluate the projected magnitude, structure, and gender disparities of long-term care needs over time. Results: Between 2030 and 2100, the number of disabled older adults in China is projected to follow an inverted U-shaped trend—peaking at 160 million in 2070 and remaining above 115 million by 2100. The share of disabled individuals among older adults rises steadily, from 39.75% to 45.28%. Person-years with disability (PYD) show sustained growth, especially among the oldest-old and women. By 2100, adults aged 95 and older contribute over 20 million PYD—eight times the 2030 level. Gender disparities widen: in 2100, women aged 85–94 account for 53.94 million severe-disability PYD, exceeding men by 8.22 million. These trends reflect mounting structural pressures on China’s long-term care system, increasingly driven by age- and gender-specific disability burdens. Conclusions: If the current disability trend continues unchecked, health risks for older adults will grow over time. In the near future, China will face an extremely heavy care burden and pressure, which will severely impact its economic and social systems. Seizing this critical window for policy action and system improvement is crucial to reducing risks in the longevity era. Full article

A novel artificial light-harvesting system (LHS) for the photooxidation reaction was constructed by the phenyl-bis-naphthyl derivative (PBN) and water-soluble phosphate-pillar[5]arene (WPP5). After host–guest interaction, WPP5 integrated with PBN to form WPP5-PBN amphiphiles, which self-assembled to WPP5-PBN nanoparticles. Based on the aggregate state of PBN in WPP5-PBN nanoparticles, WPP5-PBN nanoparticles emitted a significant yellow fluorescence as energy donors. Due to the yellow fluorescence fully covering the absorption of sulforhodamine 101 (SR101), SR101 was used as energy acceptors and loaded in WPP5-PBN nanoparticles for constructing the WPP5-PBN-SR101 LHS, whose energy transfer efficiency and antenna effect were 66.32% and 22.34. Notably, after the energy of the WPP5-PBN antenna transferred to SR101, more singlet oxygen (¹O₂) production was observed in the WPP5-PBN-SR101 LHS, which was successfully used as a photocatalyst to catalyze the oxidation reaction of 4-methoxythioanisole to 1-methoxy-4-(methylsulfinyl)benzene, imitating the solar energy conversion to chemical energy. Full article

Hydroelectricity energy harvesting has emerged as a promising, eco-friendly alternative for addressing the growing demand for sustainable energy solutions. In this study, we present a hydroelectricity energy harvester fabricated from shredded waste printing paper (WPP), offering a novel waste-to-energy conversion strategy that requires neither material purification nor complex processing. The device leverages the randomly entangled fiber network of WPP to facilitate capillary-driven moisture diffusion and electric double layer (EDL) formation, thereby enabling efficient electrokinetic energy conversion. The random arrangement of WPP fibers increases the effective EDL area, allowing the waste printing paper generator (WPPG) to achieve an open-circuit voltage of 0.372 V and a short-circuit current of 135 μA at room temperature under optimized electrolyte conditions. This study demonstrates that carbon-black-coated WPP can be effectively upcycled into a high-performance hydroelectricity generator, exhibiting excellent electrical output at ambient conditions. By combining material recycling with efficient energy conversion, this system establishes a practical and sustainable pathway for distributed power generation. Overall, this work not only presents an environmentally responsible approach to device fabrication but also highlights that hydroelectricity energy harvesting using WPPG represents a promising alternative energy route for future applications. Full article

The paper finds optimal power flows and optimal placement of wind power plants (WPPs), static var compensators (SVCs), and thyristor-controlled series capacitors (TCSCs) in the IEEE 30-bus transmission power network by applying three high-performance algorithms, such as the equilibrium optimizer (EO), the Coot optimization algorithm (COOT), and the marine predators algorithm (MPSA). The three algorithms are run for the system without any added electric components and with three single objectives, including active power losses, total fuel cost, and total voltage deviation, for comparison with other previous algorithms. The three algorithms can reach better results than many algorithms and suffer worse results than a few algorithms. EO is more effective than MPSA and COOT in all cases. For simulation cases with SVCs, TCSCs, and WPPs, the losses are significantly reduced compared to the base case. The power loss of the base case is 3.066 MW, and the best loss is 2.869 MW for two cases with two SVCs and one TCSC. When applying the obtained solution and optimizing the placement of one, two, and three WPPs, the power loss is, respectively, 2.053, 1.512, and 1.112 MW. By optimizing two SVCs, one TCSC, and WPPs simultaneously, the power loss is, respectively, 2.041, 1.508, and 1.093 MW for one, two, and three WPPs. So, the optimal placement of TCSCs, SVCs, and WPPs can result in high benefits for power systems. Full article

The thermal discharge from coastal power plants exchanges heat with the surrounding marine environment, potentially affecting the aquatic ecosystem. This study utilizes Landsat-series satellite data from 2008 to 2023 to extract the spatiotemporal distribution characteristics of thermal discharges from the Xiangshan Harbor Guohua Power Plant (GPP) and the Wushashan Power Plant (WPP). Additionally, the study investigates the impact of thermal discharge on local aquatic life by examining the spatiotemporal distribution of chlorophyll-a (Chl-a). The results indicate that (1) the overall area of thermal rise in GPP and WPP shows a decreasing trend. The interannual variation in low thermal rise zones (+1 °C, +2 °C) is substantial, with significant seasonal differences mainly influenced by seasonal sea–air temperature differences, the flow velocity of seawater at the discharge outlet, and water depth. (2) The diffusion of thermal discharge is significantly affected by tides. The area of thermal rise is larger during ebb tide compared to flood tide, and during neap tide compared to mid-tide and spring tide. During the ebb tide of the neap tide period, the total area of thermal rise in WPP is approximately three times that of GPP. (3) There is a significant positive correlation between thermal discharge and concentrations of Chl-a. Thermal discharge has complex impacts on aquatic life, primarily positive. The findings of this study provide important references for analyzing the ecological impacts of thermal discharge from coastal power plants. Full article

This study presents an optimization framework for a utility-scale hybrid power plant (HPP) that integrates wind power plants (WPPs), solar power plants (SPPs), and battery energy storage systems (BESS) using historical and probabilistic weather modeling, regulatory incentives, and multi-objective trade-offs. By employing multi-objective particle swarm optimization (MOPSO), the study simultaneously optimizes three key objectives: economic performance (maximizing net present value, NPV), system reliability (minimizing loss of power supply probability, LPSP), and operational efficiency (reducing curtailment). The optimized HPP (283 MW wind, 20 MW solar, and 500 MWh BESS) yields an NPV of $165.2 million, a levelized cost of energy (LCOE) of $0.065/kWh, an internal rate of return (IRR) of 10.24%, and a 9.24-year payback, demonstrating financial viability. Operational efficiency is maintained with <4% curtailment and 8.26% LPSP. Key findings show that grid imports improve reliability (LPSP drops to 1.89%) but reduce economic returns; higher wind speeds (11.6 m/s) allow 27% smaller designs with 54.6% capacity factors; and tax credits (30%) are crucial for viability at low PPA rates (≤$0.07/kWh). Validation via Multi-Objective Genetic Algorithm (MOGA) confirms robustness. The study improves hybrid power plant design by combining weather predictions, policy changes, and optimizing three goals, providing a flexible renewable energy option for reducing carbon emissions. Full article

Electricity markets with a high share of variable renewable energy require significant balancing reserves to ensure stability by preserving the balance of supply and demand. However, they were originally conceived for dispatchable technologies, which operate with predictable and controllable generation. As a result, adapting market mechanisms to accommodate the characteristics of variable renewables is essential for enhancing grid reliability and efficiency. This work studies the strategic behavior of a wind power producer (WPP) in the Iberian electricity market (MIBEL) and the Portuguese balancing markets (BMs), where wind farms are economically responsible for deviations and do not have support schemes. In addition to exploring current market dynamics, the study proposes new market designs for the balancing markets, with separate procurement of upward and downward secondary balancing capacity, aligning with European Electricity Regulation guidelines. The difference between market designs considers that the wind farm can hourly bid in both (New 1) or only one (New 2) balancing direction. The study considers seven strategies (S1–S7) for the participation of a wind farm in the past (S1), actual (S2 and S3), New 1 (S4) and New 2 (S5–S7) market designs. The results demonstrate that new market designs can increase the wind market value by 2% compared to the optimal scenario and by 31% compared to the operational scenario. Among the tested approaches, New 2 delivers the best operational and economic outcomes. In S7, the wind farm achieves the lowest imbalance and curtailment while maintaining the same remuneration of S4. Additionally, the difference between the optimal and operational remuneration of the WPP under the New 2 design is only 22%, indicating that this design enables the WPP to achieve remuneration levels close to the optimal case. Full article

Balancing markets (BMs) play a crucial role in ensuring the real-time equilibrium between electricity demand and supply. The current requirements for participation in BMs often overlook the characteristics and capabilities of variable renewables, limiting their effective integration. The increasing penetration of variable renewables necessitates adjustments in the design of BMs to support the transition toward carbon-neutral power systems. This study examines the levels of active market participation for a wind power producer (WPP) in the Iberian Electricity Market and the Portuguese BMs. In addition to exploring current market dynamics, the study tests one methodology proposed by the Danish Transmission System Operator to support the participation of variable renewables in BMs, the P90, and two new methods based on the full cost balancing concept. These methodologies incentivize WPPs to minimize imbalances by allowing market participation only if imbalances remain within a 10% deadband of annual hours (P90), hourly offers (D90), or both (DP90). The results indicate that participating in the secondary capacity market, particularly for downward capacity, is the most profitable strategy. This participation enhances the value of wind power by over 42%. However, in most methodologies, the WPP failed to deliver nearly 100% of its allocated capacity approximately 1% of the time. In contrast, the D90 approach limited the maximum deviation to 10%, demonstrating the highest reliability among the evaluated methods. Full article