Application Of Renewable Energy Technologies Research Articles

Experimental study on electricity generation performance of T‐type direct‐expansion solar PVT heat pump system

AbstractFocusing on the electricity generation performance of a direct expansion solar PVT heat pump system, a novel T‐type optimized collector/evaporator was designed. The experiment used refrigerant R410a as the working medium and was conducted under the average winter ambient temperature of 16°C in Fuzhou. Through experimental comparison, the differences in panel temperature, electricity generation, and efficiency under different radiation intensities were tested against traditional PV panels and honeycomb PVT panels. The experimental results showed that the T‐type PVT system exhibited significant advantages under various weather conditions. The back panel temperature was reduced by 12.74, 8.52, and 13.06°C compared to traditional PV panels and honeycomb PVT panels, respectively, and it maintained a stable increase in electricity generation. The maximum instantaneous electricity output increased by 56.6% relatively, and the total electricity generation increased by 9.3% to 14.5% compared to traditional PV panels. The photoelectric efficiency reached 21.54% and 22.6%, surpassing traditional PV panels and honeycomb PVT panels, with measured values relatively increased by 1.7%, 2.38%, and 2.76%, respectively. Economic evaluation indicated that the T‐type PVT system could save on self‐generated electricity costs, achieving savings of up to 386.50 and 210.81 yuan/year compared to traditional PV panels and honeycomb PVT panels. The T‐type PVT system demonstrated clear advantages in self‐generated electricity costs, significantly reducing costs for application scenarios and providing strong support for the practical application of renewable energy technologies.

Shape-controllable synthesis of lignin-derived boron-doped nanoporous carbons for dye adsorption and electrochemical H2O2 production

Lignin-derived nanocarbon materials (LNCMs) have attracted intense attention due to their excellent properties and promising applications in renewable energy technologies. However, lignins tend to melt and agglomerate during pyrolysis, make it difficult to control the morphology and pore structure of the resulting carbon. In this study, boron-doped porous nanocarbon (BFC) in various shapes (sphere, band, and sheet) were synthesized using ammonium borate as a crosslinking agent to prevent lignin melting, assisted by liquid nitrogen freeze-drying and potassium phosphate (KP) templating. The effects of BFC structure on methylene blue adsorption and electrochemical generation of H2O2 were investigated. The results show that KP-1/1-8BFC exhibits a high specific surface area (912.89 m2/g) and a hierarchical micro-mesoporous structure, achieving a remarkable adsorption capacity of 473.9 mg/g for methylene blue and rapid kinetics. The selectivity of KP-1/20-8BFC for electrochemical production of H2O2 reaches 85 %. This study offers theoretical guidance for the controllable synthesis of LNCMs, contributing to the advancement of sustainable energy solutions.

Electricity generation via metal oxide-air moist interaction

Harvesting electricity from ambient moisture and water droplets through the innovative technology of hydrovoltaics has lately gained attraction as it only requires water molecules' intrinsic energy and is applicable in different weather conditions. We present a device prototype for electricity generation from air humidity. The study investigates the complex interplay of water-solid interactions, focusing on band gap differences of n-type and p-type couple metal oxides and their performance in electricity generation. The research develops Moist-Electric Generators (MEGs) using ZnO as an n-type metal oxide with various p-type metal oxides (MnOx, CuO, and CoOx) on carbon paper substrates. Among these, the ZnO/CoOx MEG exhibits superior performance, producing an open circuit voltage of nearly 0.5 V, a current of around 9.5 µA for more than 7 days, with an areal and maximum power density of 1.48 µWcm2- and 4.5 µWcm2- at 95 % RH. Detailed characterization techniques, including XRD, XPS, and SEM, confirm the successful synthesis of ZnO and CoOx electrodes. The study demonstrates the sensitivity of the ZnO/CoOx MEG to changes in relative humidity and investigates its long-term stability. The results highlight the significance of water dissociation and minor redox processes for efficient energy generation, paving the way for advanced applications in renewable energy technologies.

Dissolution Heterogeneity Observed in Anisotropic Ruthenium Dioxide Nanocrystals via Liquid-Phase Transmission Electron Microscopy.

Noble metal oxides such as ruthenium dioxide are highly active electrocatalysts for anodic reactions in acidic electrolytes, but dissolution during electrochemical operation impedes wide-scale applications in renewable energy technologies. Improving the fundamental understanding of the dissolution dynamics of application-relevant morphologies such as nanocrystals is critical for the grid-scale implementation of these materials. Herein, we report the nanoscale heterogeneity observed via liquid-phase transmission electron microscopy during ruthenium dioxide nanocrystal dissolution under oxidizing conditions. Single-crystalline ruthenium dioxide nanocrystals enabled the direct observation of dissolution along different crystallographic facets, allowing an unprecedented direct comparison of crystal facet stability. The nanoscale observations revealed substantial heterogeneity in the relative stability of crystallographic facets across different nanocrystals, attributed to the nanoscale strains present in these crystals. These findings highlight the importance of nanoscale heterogeneity in determining macroscale properties such as electrocatalyst stability and provide a characterization methodology that can be integrated into next-generation electrocatalyst discovery efforts.

Tunable Photocatalytic Activity of CoFe Prussian Blue Analogue Modified SrTiO3 Core-Shell Structures for Solar-Driven Water Oxidation.

This study presents a pioneering semiconductor-catalyst core-shell architecture designed to enhance photocatalytic water oxidation activity significantly. This innovative assembly involves the in situ deposition of CoFe Prussian blue analogue (PBA) particles onto SrTiO3 (STO) and blue SrTiO3 (bSTO) nanocubes, effectively establishing a robust p-n junction, as demonstrated by Mott-Schottky analysis. Of notable significance, the STO/PB core-shell catalyst displayed remarkable photocatalytic performance, achieving an oxygen evolution rate of 129.6 μmol g-1 h-1, with stability over an extended 9-h in the presence of S2O82- as an electron scavenger. Thorough characterization unequivocally verified the precise alignment of the band energies within the STO/PB core-shell assembly. Our research underscores the critical role of tailored semiconductor-catalyst interfaces in advancing the realm of photocatalysis and its broader applications in renewable energy technologies.

Evaluation and prediction of the life of vulnerable parts and lithium-ion batteries in electrochemical energy storage power station

The widespread application of renewable energy technology and changes in energy structure has led to changes in the structure and operation of traditional power grids. Electrochemical energy storage systems have gradually achieved commercial operation due to their high energy density, efficient energy conversion, and renewability. This article proposes a life assessment plan for vulnerable parts, conducts statistical analysis on the life data of vulnerable parts, and provides calculation methods for average life, reliability, and reliable life. Then, the residual capacity of lithium-ion is estimated by using electron dispersion spectroscopy, and a dual exponential capacity decay model is established. Finally, the residual life of lithium-ion is estimated through an extended Kalman filter, and the capacity attenuation trend is better captured by combining with Monte Carlo sampling to improve the accuracy of the remaining useful life of lithium-ion.

A lignin–derived N-doped carbon-supported iron-based nanocomposite as high-efficiency oxygen reduction reaction electrocatalyst

Fuel cells are a promising renewable energy technology that depend heavily on noble metal Pt-based catalysts, particularly for the oxygen reduction reaction (ORR). The discovery of new, efficient non-precious metal ORR catalysts is critical for the continued development of cost-effective, high-performance fuel cells. The synthesized carbon material showed excellent electrocatalytic activity for the ORR, with half-wave potential (E1/2) and limiting current density (JL) of 0.88 V and 5.10 mA·cm−2 in alkaline electrolyte, respectively. The material has a Tafel slope of (65 mV dec−1), which is close to commercial Pt/C catalysts (60 mV dec−1). Moreover, the prepared materials exhibited excellent performance when assembled as cathodes for zinc-air batteries. The power density reached 110.02 mW cm−2 and the theoretical specific capacity was 801.21 mAh g−1, which was higher than that of the Pt/C catalyst (751.19 mAh g−1). In this study, with the assistance of Mg5(CO3)4(OH)2·4H2O, we introduce an innovative approach to synthesize advanced carbon materials, achieving precise control over the material's structure and properties. This research bridges a crucial gap in material science, with potential applications in renewable energy technologies, particularly in enhancing catalysts for fuel cells.

Towards the application of renewable energy technologies in green ports: Technical and economic perspectives

AbstractWith growing concerns over environmental degradation and climate change, the shipping industry is under increasing pressure to reduce its environmental impact. This has led to the development of green port initiatives in the field of maritime transport and logistics, which aim to promote sustainable practices and reduce the environmental footprint of ports and their operations. One of the key strategies for achieving this goal is the use of renewable energy technologies (RETs). This paper summarizes the potentials, challenges, and economic analysis of RETs applications in green ports, emphasizing those that require aquatic environments for operation, including floating photovoltaic systems, offshore wind turbines, and ocean energy. The paper investigates the concept of green ports and explores the feasibility of integrating RETs into these facilities. Also, the potential of the various RETs is presented in terms of technical and economic aspects and installed capacity. Additionally, due to high flexibility in electrical systems and compatibility with maritime transportation, the use of fuel cells in green ports has been discussed as a feasible solution for supplying power to ports (either as the primary or backup source). The findings of this study show that RETs can significantly contribute to achieving sustainable goals in the maritime industry and pave the way for the creation of more efficient and environmentally friendly ports.

Energy saving in industrial buildings using advanced concentrated solar thermal systems

Saving energy in industrial buildings is one of the ten pillars of the European Green Deal. The application of renewable energy technologies in industrial processes and their buildings is an appropriate way to support the European energy goals. The paper presents an innovative solar heating method for industrial buildings that focuses on overcoming the current limitations of these systems. The method is based on the modular and flexible integration of two innovative technologies for the solar collector (SunDial technology – parabolic collectors) and thermal energy storage (based on phase change materials, PCM) which, through a control system, allow flexible operation to maintain continuous use against the unpredictable nature of the solar source and partly even during the night. The method can cover a significant percentage of the heat demand in industrial processes that use temperatures above 150°C. At the same time, there is the possibility of meeting cooling needs using an absorption chiller.The work describes the technologies of centralized solar collectors and the connection, operation, control and monitoring systems as well as the possibilities of covering thermal and cooling loads in an industrial building. This technology can be applied to both commercial and residential buildings. The purpose of this application is to contribute to the reduction of the requirements for heating and cooling in industrial buildings of the European Union which is estimated at approximately 72TWh per year.

An improved model for building energy consumption prediction based on time-series analysis

The development and popularisation of renewable energy is necessary. The application of renewable energy technology in buildings is an important research direction. Moreover, the prediction of renewable energy consumption in this direction is an essential research content. In view of this, a building energy consumption prediction model of renewable energy based on time-series analysis and a support vector machine (SVM) is proposed. The performance test of this model showed that its loss value was as low as 1.5% in the training set, and the loss value was 4.1% in the test set. In addition, it showed the highest accuracy rate of 95.5% in the neural network accuracy test, which is significantly higher than that of traditional algorithms. About the overall energy consumption prediction ability of the model, the experimental results showed that the lowest error of the energy consumption prediction model was 2.3%, the average relative error of the traditional SVM model in the same data set was 6.8% and that of the chaotic time-series model was 4.1%. Compared with the prediction ability of the traditional models currently used, the prediction ability of the energy consumption prediction model has been greatly improved, and it has the potential to be put into practical application.

State financial regulation of renewable energy development

The article considers financial incentives for the development and application of renewable energy technologies. The authors argue that state support is necessary to make renewable energy competitive with non-renewable energy. The state financial regulation of renewable energy is fixed by corresponding programme documents. Green bonds, block grants, reduced rates of customs duties, subsidies and preferential lending can be used as instruments of financial stimulation in different countries. The article points out the remaining obstacles and barriers that limit the wide application of renewable energy.

Well-to-Wheel Analysis of Electric and Hydrogen Light Rail

The application of renewable energy technologies to rail transit should be evaluated on a comprehensive energy pathway efficiency basis to ensure that the renewable energy technology is truly beneficial. One such method is the well-to-wheel analysis method, which combines the energy efficiencies of each component of the energy pathway into a single energy efficiency value. The focus of this paper is on well-to-wheel analysis of electric and hydrogen light rail. The inefficiencies of the hydrogen train’s power plant and hydrogen production process are apparent in the hydrogen train’s well-to-wheel efficiency value of 16.6–19.6%. The electric train, due to improved pathway efficiencies, uses substantially less feedstock energy with a well-to-wheel efficiency value of 25.3%. While this result is specific to Charlotte, North Carolina, the electric train efficiency is influenced by the main source of electricity production—it is 24.6% in Cleveland, Ohio (coal heavy) and 50.3% in Portland, Oregon (hydroelectric heavy).

Technical, economic, and environmental assessment of the distribution power system with the application of renewable energy technologies

Renewable energy technologies (RETs) have been universally accepted as the prospective choice to increase the reliability of the power system and reduce the effects of emission cost (EC), fuel cost (FC), maintenance cost (MC), power loss (PL), total annual cost (TAC) and voltage deviation (VD). The performance indicators are used in the study to assess the effects of diesel generator (DG), electric storage system (ESS), photovoltaic (PV) and wind turbine generator (WTG) on the environmental, economic, and technical performance of a microgrid system with modified Roy Billiton Test System (RBTS) bus 4 distribution network. The proposed model is utilized to achieve the goals of the study by minimizing the costs that are identified with the power outages, TAC, MC, EC, FC, PL, and VD of the system with the application of an intelligent optimal control method based on the fmincon solver. The outcomes of the study can be used as benchmarks to assess the cost-effectiveness of increasing the capacity of universal power supply and resolve the universal power crisis owing to the depletion of fossil fuels. The study provides vital information to enhance the efficiency of the power system and the guidelines to promote the development of sustainable energy.

Technical, Economic, and Environmental Assessment of the Distribution Power System with the Application of Renewable Energy Technologies

Technical, Economic, and Environmental Assessment of the Distribution Power System with the Application of Renewable Energy Technologies

Optimization of PV modules layout on high-rise building skins using a BIM-based generative design approach

Global economic growth is leading to a higher demand for energy. Considering the declining cost of technology and rising fossil fuel prices, the application of renewable energy technologies is promising. The worldwide use of photovoltaic electricity is growing rapidly by more than50% a year. In the urban environment, buildings are central to human activities. Therefore, to achieve sustainable urban development, buildings are of particular importance for distributed renewable energy generation. Of different types of buildings in the built environment, high-rise buildings are of particular interest because of their high potential for harvesting a considerable amount of photovoltaic (PV) energy on vertical and horizontal surfaces. Nevertheless, this high potential is seldom harnessed mainly because the deployment of PV modules on high-rise buildings involves consideration of a complex interplay between various factors that affect the installation of PV modules (e.g., urban canyons, self-shadowing effect, surface-specific PV modules, etc.). This renders the design of PV modules in high-rise buildings a complex optimization problem, one that requires a generative design approach. In recent years, and with the advent and rising popularity of Building Information Modeling (BIM) concept, the apparatus for the implementation of such a comprehensive generative design approach is becoming increasingly available. However, to the best of authors’ knowledge, there are currently no frameworks for the BIM-based generative design of PV modules for high-rise buildings. To this end, the present paper made a novel contribution to the body of knowledge by presenting a BIM-based generative design framework for PV module layout design on the whole exterior of tall buildings. This allows designers to consider the complex interaction between building surface types (e.g., windows, walls, etc.), type of PV module (e.g., opaque, semi-transparent, etc.), the efficiency of different PV modules, and the financial aspect of the PV system (i.e., revenue vs. cost at different study period). The results generated by the elaborate case study demonstrated that the generative design framework is capable of offering more favourable solutions (i.e., either or both of reduced costs and increased energy revenue) compared to baseline scenarios. It is observed that, in the majority of the studied scenarios, the optimum solutions favored a more consistent orientation of the panels (i.e., consistent pan and tilt angles across all the panels).

Microwave-Assisted Auto-Combustion Synthesis of Binary/Ternary Co x Ni1-x Ferrite for Electrochemical Hydrogen and Oxygen Evolution.

Enormous efforts have been dedicated to engineering low-cost and efficient electrocatalysts for both hydrogen evolution and oxygen evolution reactions (HER and OER, respectively). For this, the current contribution reports the successful synthesis of binary/ternary metal ferrites (CoxNi1–xFerrite; x = 0.0, 0.1, 0.3, 0.5, 0.7, and 1.0) by a simple one-step microwave technique and subsequently discusses its chemical and electrochemical properties. The X-ray diffraction analysis substantiated the phase purity of the as-obtained catalysts with various compositions. Additionally, the morphology of the nanoparticles was identified via transmission electron microscopy. Further, the vibrating sample magnetometer justified the ferromagnetic character of the as-prepared products. The electrochemical measurements revealed that the as-prepared materials required the overpotentials of 422–600 and 419–467 mV for HER and OER, respectively, to afford current densities of 10 mA cm–2. In the general sense, Ni cation substitution with Co influenced favorably toward both HER and OER. Among all synthesized electrocatalysts, Co0.9Ni0.1Ferrite displayed the highest performance in terms of OER in 1 M KOH solution, which is related to the synergistic effect of multiple parameters including the optimal substitution amount of Co, the highest Brunauer–Emmett–Teller surface area, the smallest particle size among all samples (26.71 nm), and the lowest charge transfer resistance. The successful synthesis of ternary ferrites carried out for the first time via a microwave-assisted auto-combustion route opens up a new path for their applications in renewable energy technologies.

Exploring the Critical Barriers to the Implementation of Renewable Technologies in Existing University Buildings

For more than a decade, the European Union has been implementing an ambitious energy policy focused on reducing CO2 emissions, increasing the use of renewable energy and improving energy efficiency. This paper investigates the factors that hinder the application of renewable energy technologies (RETs) in existing university buildings in Spain and Portugal. Following a qualitative methodology, 33 technicians working in the infrastructure management offices of 24 universities have been interviewed. The factors identified have been classified into economic-financial, administrative and legislative barriers, architectural, urban planning, technological, networking, social acceptance, institutional and others. It is concluded that there have not been sufficient economic incentives to carry out RETs projects in this type of building. Conditioning factors can act individually or jointly, generating a greater effect. Most participants consider that there are no social acceptance barriers. Knowledge of these determinants can facilitate actions that help implement this technology on university campuses in both countries.

Carbon-Based Metal-Free Electrocatalysts: Past, Present, and Future

ConspectusDue to the overuse of fossil fuels, various detrimental effects along with the excess CO2 emissions have induced global warming and sea-level rising. To tackle climate change and provide a cleaner environment for the air we breathe and water we consume, the existing energy mix needs to be changed into fossil-free, clean, renewable energy with zero emission (e.g., fuel cells). While providing a promising and scalable strategy to the energy and environmental challenges, renewable energy processes often involve noble-metal-based catalysts (i.e., Pt, RuO2). However, the disadvantages of noble-metal-based catalysts, including their high cost and scarcity, have hampered the large-scale application of renewable energy technologies. In 2009, we discovered earth-abundant carbon materials functioning as efficient low-cost, carbon-based metal-free electrocatalysts (C-MFECs) attractive for renewable energy and environmental remediation. Since then, C-MFECs have become an emerging new research field over the world. They are demonstrated to be efficient multifunctional catalysts for various key reactions important to renewable energy and environmental technologies, including oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), oxygen evolution reaction (OER), CO2 reduction reaction (CO2RR), and N2 reduction reaction (NRR), to name a few. Charge transfer/redistribution induced by heteroatom (e.g., N) and/or defect doping was recognized as the driving force for the metal-free catalytic activities. This finding has been used as a guidance to design and develop various new and multifunctional C-MFECs for many reactions even beyond the renewable energy and environmental remediation. In this Account, we first summarize our previous work on the development and mechanistic understanding of C-MFECs for ORR, HER, and OER to promote renewable energy conversion and storage. Then, we present recent advances in C-MFECs for new important reactions for environment remediation (e.g., CO2RR, NRR), seawater splitting, and metal–CO2 batteries. However, different dopant locations for C-MFECs even with the same doping element and content can cause variable catalytic properties for heteroatom-doped carbon materials. Therefore, vast opportunities remain for further developing numerous innovative C-MFECs with defined structures to gain a better understanding of their structure-based properties. In this context, we finally conclude with the current challenges and future perspectives in this exciting field.

Effectiveness of Chinese Regulatory Planning in Mitigating and Adapting to Climate Change: Comparative Analysis Based on Q Methodology

With cities considered the main source of carbon emissions, urban planning could mitigate and help adapt to climate change, given the allocation and regulation of public policies of urban spatial resources. China’s regulatory planning remains the basis for building permission in the original urban and rural planning, and the new territorial spatial planning systems, determining the quality of urban plan implementation. Comprehensive regulatory plans effectively reduce carbon emissions. This study employs Q methodology to compare and analyze urban planners’ and practitioners’ perceptions of China’s regulatory planning in climate change mitigation and adaptation. The findings show that while regulatory planning is key, potential deficiencies include the gaps between regulatory from master plans, capacity shortages of designations and indicators, and unequal rights and responsibilities of local governments. However, mandatory indicators in regulatory planning, especially “greening rate,” “building density,” “land use type,” and “application of renewable energy technologies to the development of municipal infrastructure” could effectively mitigate climate change. “Greening rate” is the core indicator in regulatory planning since it provides empirical evidence for the “green space effect”. This study indicates that local customization of combined regulation of greening rate and green spaces could help mitigate and help China adapt to climate change.

Agricultural Land or Photovoltaic Parks? The Water–Energy–Food Nexus and Land Development Perspectives in the Thessaly Plain, Greece

Water, energy, land, and food are vital elements with multiple interactions. In this context, the concept of a water–energy–food (WEF) nexus was manifested as a natural resource management approach, aiming at promoting sustainable development at the international, national, or local level and eliminating the negative effects that result from the use of each of the four resources against the other three. At the same time, the transition to green energy through the application of renewable energy technologies is changing and perplexing the relationships between the constituent elements of the nexus, introducing new conflicts, particularly related to land use for energy production vs. food. Specifically, one of the most widespread “green” technologies is photovoltaic (PV) solar energy, now being the third foremost renewable energy source in terms of global installed capacity. However, the growing development of PV systems results in ever expanding occupation of agricultural lands, which are most advantageous for siting PV parks. Using as study area the Thessaly Plain, the largest agricultural area in Greece, we investigate the relationship between photovoltaic power plant development and food production in an attempt to reveal both their conflicts and their synergies.