Renewable and Sustainable Energy Reviews最新文献

The emphasis of modern society on environmental sustainability is accompanied by a lesser-known paradox. Rare earth permanent magnet machines play an essential role in renewable energy conversion and green transportation, critical sectors of the green transition. However, the mining and processing of rare earth metals required for these machines is energy-intensive and has significant environmental impacts. As a result, the increased use of rare earth permanent magnets to mitigate ecological concerns may lead to further environmental degradation. This paper presents a comprehensive literature review addressing this Catch-22 trap by surveying the main solutions to reduce the need for newly mined and processed rare earth materials. A special focus is set on the approaches applicable in this sense in the field of electrical machines required for the sustainable development of society.

The efficient use of biomass is crucial for global efforts to reduce carbon emissions. Biomass-coupled electrochemical upgrading can convert low-cost biomass crude products into high-value organic molecules with minimal energy consumption. In contrast to conventional thermochemistry, which necessitates the application of heat (200–400 °C), pressure (4–20 MPa) and a hydrogen supply, electrochemical hydrogenation is conducted under relatively mild conditions. This study concentrates on the product distribution of typical biomass aldehydes, namely furfural, 5-hydroxymethylfurfural and benzaldehyde, during electrochemical reduction with varying hydrogenation depths. Additionally, it is examined the underlying mechanisms of electrochemical reduction, including hydrogenation, hydrogenolysis and dimerization by the comparison of aldehydes' thermochemical and electrochemical upgrading. Furthermore, it explores the effect of intermolecular interactions of these aldehydes on electrocatalytic reduction in mixed systems. The study expands the hydrogenation polymerization of single molecules to intermolecular hydrogenation polymerization of various aldehydes, resulting in multifunctional high-carbon organic molecules that can serve as fuel precursors. This research presents a new approach to upgrading biomass-based platform molecules, opening up new possibilities for the multifaceted application of biomass in the field of fuels.

In the rapidly evolving landscape of energy storage, lithium-ion batteries stand at the forefront, powering a vast array of devices from mobile phones to electric vehicles and renewable energy systems. Despite their widespread adoption, inconsistencies in production processes, cell grouping, and thermal management lead to parameter variations such as voltage, temperature, and current, elevating the risks of overcharging, over-discharging, and accelerated degradation. Hence, it is imperative to explore the complete lifecycle degradation mechanisms, along with the health prediction and management of lithium-ion batteries. This exploration is vital for their further advancement and innovation. Additionally, this research promises to yield innovative methodologies and insights for depicting aging behaviors and managing the health of diverse mechanical, electrical, or physical systems that exhibit similar characteristics of aging. This work offers a comprehensive review and analysis of the most recent developments in the aging mechanisms, health prognostics, and management strategies specific to lithium-ion batteries. Furthermore, it introduces fresh perspectives and approaches for the prediction and management of battery health, thereby extending its utility and providing valuable guidelines for the health management of systems analogous in nature.

Proper waste management is a key element in the transition to a sustainable bioeconomy. Population growth and the demand for food and services have led to an ever-increasing production of biotic waste whose disposal in landfills is no longer considered a sustainable option. For this reason, efforts are being made to find an appropriate management strategy for biotic waste, whose organic content allows it to be considered as a resource for the development of biotechnological and/or biorefinery processes. Assessing the sustainability of alternative options is of paramount importance. To this end, this systematic review researches trends in waste management in terms of technology and sustainability profile according to the life-cycle approach and multi-criteria analysis. The aim is to provide insights into potential resource recovery and waste valorization schemes towards high-value-added products in the marketplace, beyond their direct energy recovery. Our results show that future studies should focus on the development of multi-criteria analysis from an SSbD perspective, so that all pillars of sustainability and risk assessment are properly assessed from an early design stage.

Reducing the operational energy demand while maintaining a comfortable thermal environment is an essential approach to achieving energy-efficient buildings. The premise lies in accurately assessing and predicting the occupant's thermal sensation. However, most thermal comfort models are not entirely suitable for dwellings, since the effects of time scale, occupant's trajectory, and connectivity between partitioned spaces or rooms in typical dwellings have been ignored. Hence, taking Fanger's model as an example, a modified thermal comfort model involving time scale and habitual trajectory was proposed by changing the mathematical structure, namely the PMVt model. A Python-based visualization program was written to simplify its calculation process. The elderly living in mixed-mode ventilation dwellings in Shanghai were invited to conduct relevant experiments during the summer season. Based on 447 valid thermal sensation votes, weighted and specified indicators corresponding to immediate and delayed inquiries were proposed, respectively. The results show that the PMVt model achieves satisfactory evaluation and prediction accuracy. Moreover, considering time scale and habitual trajectory independently results in a significant reduction in model accuracy, indicating that the synergistic utilization of time scale and trajectory is critical to reducing model errors. Lastly, the applications of the PMVt model in energy-saving strategies for intelligent buildings are prospected, including evaluating thermal comfort, optimizing operation strategy, avoiding energy waste, and reducing energy burden.

Due to their rapid commercialisation, Photovoltaic (PV) systems are considered the foundation of present and future renewable energy. Nonetheless, the full potential of this technology has yet to be realised because of several challenges. Consequently, effective solutions are critical for achieving high solar PV performance. This work aims to consolidate and provide a unique global review of pioneering recent studies on the most influential factors affecting solar PV performance. Four driven parameters are emphasised: dust/soil, tilt angle, temperature, and humidity. Regional, national and international experiments performed indoor, outdoor and at the laboratory, real-scale studies and numerical simulation dealing with PV performance challenges and potential routes for improvement and optimisation are reported. The review included studies from across the world, including the Middle East, Africa, the Asia Pacific, America and Europe. The figures and detailed tables with pertinent information on the key subject are provided. The studies suggest that the dust can reduce PV efficiency by up to 24 %. Adjusting PV module alignment up to five times a year can enhance energy yield by 3.63 %. The efficiency drops by 0.05 %/°C, with the temperature increase from 25 °C to 45 °C causing an efficiency drop of up to 20.22 %. This paper provides a comprehensive analysis of the thermal management, economic implications, environmental impact, and disposal concerns associated with end-of-life PV modules, highlighting the need for effective regulations to address emerging challenges. Finally, this work can be used as a pertinent guide for communities working in the field of solar PV involving researchers, industrialists and policymakers in the design, sizing, application and commercialisation of high-performance PV technologies and systems.

The frequent appearance of intense and abrupt weather episodes, geological disasters, and geopolitical instabilities pose challenges to the provision of distributed backup power sources. Such a situation has become even more severe, because the energy system is shifting towards decentralized energy production. Thermoelectric generator (TEG) as a solid-state energy conversion technology with captivating prospects has gained substantial attention due to its inborn nature of miniaturization, structure simplicity, little maintenance, and high energy density. TEG, integrated with fuel oxidation (biomass, hydrogen, and hydrocarbon combustion), becomes a potential distributed backup power source. Although the first concept of combustion powered TEG (CPTEG) was proposed for the first time in the 1950s, subsequent investigations proceeded very slowly, gaining attention again approximately 46 years later in 1996. Indeed, the reality that people increasingly rely on electricity in a society full of chaotic weather and geopolitical instabilities attracts many researchers to discover the TEG's potential. This has brought a growing number of studies on CPTEG and spectacularly increased expectations towards commercialization. This paper provides a detailed research roadmap by categorizing the papers published on CPTEG, showcasing the state-of-the-art, and revealing several important challenges before successful commercialization. Comprehensive discussions and analysis show that there are four interrelated, interactive, and restricted aspects that cause dense fogs of ongoing research and possible commercialization. The abovementioned aspects include combustion organization-capacity-noise, thermal collection-distribution-rejection, mechanical design-processing-cost, and electrical conditioning-management-robustness. At present, CPTEGs fueled with hydrogen or hydrocarbon are approaching the upper power generation efficiency, and advanced TE materials must be introduced to furtherly augment the performance. Besides, standalone operation and low noise level are two other aspects that gain less attention and must be solved before commercialization. On the other hand, CPTEGs fueled with biomass are still far from optimal ones, and combustion stability and efficient heat collection are two major technical obstacles.

Reduced energy consumption is essential for a rapid transition to net zero carbon emissions. Residential energy may constitute 27 % of primary energy consumption, and 20 %–50 % of residential energy is water-related energy (WRE). However, residential WRE consumption is difficult to quantify due to challenges in collecting data. The aim of this literature review is to critically appraise and compare models of residential WRE. This is the first literature review to provide a comparison of modelled estimates of residential WRE consumption. Reported values for residential WRE consumption were highly variable, ranging from 1 to 7 kWh/person/day. The results are not representative of the global population because 50 % of studies were conducted in Europe, while remaining studies were scattered across eight countries. 30 % of studies quantified energy consumption of specific end-uses (e.g. shower), and 40 % of studies only considered average consumption. Of the 61 studies reviewed, only four studies demonstrated clear validation of WRE consumption, and no studies validated energy consumption of individual end-uses. Therefore, it is difficult to determine whether the variability in reported results is due to true variability in residential WRE consumption, or uncertainty in the modelling approaches. Since successful water and energy reduction has been based on knowledge of specific end-uses, WRE models need better consideration of end-uses in order to inform design of interventions to reduce WRE consumption. Future research in this area also requires a greater focus on validation of modelling tools and wider geographical scope.

Renewable Power-to-Hydrogen (P2H2) system is an emerging decarbonization strategy for achieving global carbon neutrality. However, the propensity of hydrogen to leak and diffuse from the P2H2 facility poses great challenges to scaling up and safe applications. Accurate and efficient prediction of hydrogen jet and diffusion is critical to ensure the safety and efficacy of P2H2 system. Deep learning methods have shown promise in predicting gas jet and diffusion, but their generalization is limited, because of insufficient simulation data and excluding physical laws during the training process. This study develops a physics-informed graph neural network (Physics_GNN) for hydrogen jet and diffusion prediction using sparse sensor data. Graph network is applied to model the spatial dependency between sensor data and governing equations, so the hydrogen jet and diffusion is immediately solved at each graph node. The computed residuals are then applied to constrain the training process of the graph network. Experimental data of subsonic and under-expanded hydrogen jet and diffusion are applied to validate the model. Results demonstrated Physics_GNN exhibits 1000 times higher prediction accuracy compared to state-of-the-art physics-informed neural network and 100 times faster than CFD simulation. It enables accurate and rapid prediction of hydrogen jet and diffusion concentration and velocity, supporting safety design, operation management and rulemaking of P2H2 system in future.

This study examines land-based oscillating water column (OWC) devices numerically and experimentally subjected to the action of regular and irregular waves. The higher-order boundary element method was used to develop the numerical model for the simulation of a single- and dual-chamber OWC. A comparison of the performance of both structures is presented. The JONSWAP spectrum method was employed to generate the irregular waves. Physical experiments were conducted to validate the accuracy of the numerical results and demonstrate the variation of aerodynamic and viscous damping effects in the two device configurations. The dual-chamber configuration is proved to broaden the effective frequency bandwidth. The addition of the internal wall reduces the higher-order wave components inside the chamber. The single-chamber OWC efficiency in irregular wave conditions is approximately 5–12 % lower than in regular wave conditions. The dual-chamber OWC efficiency is reduced at the resonance condition in irregular waves but improved in the low wave-frequency region. It is shown that partial sloshing inside the chambers always occurs under the action of the irregular waves, and this phenomenon is more frequently observed in short period waves. A bottom slope is introduced to enhance the dual-chamber converter peak efficiency in the low-frequency, irregular wave conditions whilst the flat-bottomed OWC demonstrates a wider overall effective frequency bandwidth. The hydrodynamic efficiency of the individual chambers in the OWC is less sensitive to significant wave heights; a finding which contrasts with the case of regular waves.