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Overview on recent developments in energy storage: Mechanical, electrochemical and hydrogen technologies
... The reservoirs can be used to store energy when its cost is low or the production from the grid is higher than the demand, then PHS can work in the opposite way producing energy in the night when renewables are not available. [38]. PHS is a mature technology that offers a long storage period, high efficiency that can reach 87%, relative low capital cost per unit of energy, and fast response time (less than one minute). ...
... As an additional benefit the water reservoirs can be used to provide water to the population and agriculture. The introduction of hydrokinetic micro-turbines lowered the PHS size, allowing the construction of smaller plants giving the opportunity to apply PHS also to small realities with a lower environmental impact [38] 2.1. ...
... An additional benefit of fly wheels is the possibility of being operated in parallel. [38] Figure 35 A typical flywheel configuration [38] A growth in FES market has been estimated especially due to the needs of growing population in developing countries where global demand of power often creates a gap between demand and supply, in this framework FES could be used as power ...
In 2015 United Nations published an Agenda for Sustainable Development, with 17 Sustainable Development Goals (SDG), representing “a plan of action for overcoming poverty while protecting the planet and ensuring that all people enjoy peace and prosperity”. The SDG stress that economic growth needs to be fulfilled taking into consideration social responsibility and environment protection. For what concerns environment protection, goal 13 “Climate action” is becoming imperative. Greenhouse effect is seen as the main contributor to climate change and therefore one of the most urgent actions to be taken is reducing emission of greenhouse effect gas (GHG). Similarly, energy is needed for developed and developing countries so also goal 7 “Affordable and Clean Energy” needs to be among top priorities, aiming to have clean energy at low cost.
Energy companies are one of the primary sources of greenhouse gases, they utilize about 57% of global fuel produced worldwide. Even if renewables are expected to be the fastest growing source of energy, with primary share growing from 3% in 2015 to 10% in 2035, natural gas is expected to grow faster than oil and coal, overtaking coal to be the second largest energy source in 2035. For this reason, main Energy industries have endorsed an agenda for sustainability, focusing on carbon footprint reduction. Baker Hughes as energy technology company has taken the commitment to achieve a 50% reduction in CO2 equivalent emissions from own operations by 2030 and net zero CO2 equivalent emissions by 2050. This commitment aligns Baker Hughes with the Paris Climate Agreement targeting to limit global warming to 1.5 degrees Celsius.
During the timeframe of this PhD work the world went through two main crises that strongly impacted the energy sector. In 2020 the world faced its first global pandemic: Covid-19 has changed the lifestyle of the whole world population. Due to the pandemic many countries established lockdowns, forcing people to stay home limiting their activities, global energy demand dropped by 5% in 2020, with the positive effect of reducing energy-related CO2 emissions by 7%, and the negative one of decreasing global energy investment by 18%. In 2021, still many economies were suffering the weight of Covid-19 lockdowns. Nevertheless, renewable sources of energy such as wind and solar PV continued to grow rapidly, and electric vehicles set new sales records. Many countries following the 26th Conference of the Parties (COP26) call took new commitments for contributing to the global effort to reach climate goals; more than 50 countries, as well as the entire European Union, have pledged to meet net zero emissions targets. In 2022, while I am writing, the world is in the middle of its first global energy crisis after Russia’s invasion of Ukraine. Russia has been by far the world’s largest exporter of fossil fuels, and its restrictions of natural gas supply to Europe and European sanctions on imports of oil and coal from Russia are affecting the energy market. Prices for spot purchases of natural gas have reached levels never seen before, exceeding the equivalent of USD 250 for a barrel of oil. Coal has also hit record prices, while oil rose well above USD 100 per barrel in mid‐2022 before falling back. Higher energy prices are also increasing food insecurity in many developing economies, with the heaviest burden falling on poorer households where a larger share of income is spent on energy and food. Some 75 million people who recently gained access to electricity are likely to lose the ability to pay for it, meaning that for the first time since we started tracking it, the total number of people worldwide without electricity access has started to rise. Almost 100 million people may be pushed back into reliance on firewood for cooking instead of cleaner and healthier solutions. On the other side this could be a boost for improving energy efficiency and changing consumption habits in some of the most emitting countries. In the last three years energy markets and policies have changed because of Covid-19 and Russia’s invasion of Ukraine, not just for the time being, but for decades to come. The need for clean energy and the urgency of cost‐competitive and affordable clean energy are now stronger, together with the energy security. This alignment of economic, climate and security priorities has finally started to push the world towards a better value for the people, for the prosperity, and for the planet. It has been recognized as essential not to leave anyone behind, especially at a time when geopolitical crisis on energy and climate are more visible. The journey to a more secure and sustainable energy system may not be a smooth one. But today’s crisis makes it crystal clear why we need to press ahead.
In this thesis the social, environmental, and cost impact of innovative manufacturing technologies recently introduced in Baker Hughes were analyzed, excluding use phase impacts, being product’s performances invariant. Since innovation is a complex social process, where monetary interest is strongly related to social acceptance, it is important to validate its impact on stakeholders taking in account also the risks related to the new technology introduction. The scope of this research is to conduct a comprehensive assessment of all the major sources of ecological impacts (energy use, waste, resource consumption etc.) and categories of impacts (climate change, toxicity, land use, etc.), analyzing impact for specific use cases of gas turbine’s component production options, so that stakeholders can make an informed decision on which technology to buy or use, as well as find reference data to identify the sectors causing the greatest social impacts (hot spots). Main target can be summarized as:
1. Define the correct indicators that can lead to a sustainable future, proposing a path that can be beneficial for energy companies and for the society.
2. Compare the applicable methodologies for product sustainability assessment providing direction to the best tools and databases to be used.
3. Evaluate the environmental and social performance of background processes finding main drivers and negligible parameters to simplify future decision maker’s choices.
The state of the art of Sustainability and application in energy companies will be presented in Chapter 1, followed by the explanation of the energy trilemma in chapter 2. Current methodologies and tools available for environmental and social Life Cycle assessment will be presented in chapters 3 and 4 including a proposal to evaluate social life cycle assessment (SLCA) of products, to take decision and prioritize company activities on that taking into consideration what is called “triple bottom line”: society, environment, and prosperity. SLCA together with environmental life cycle assessment (ELCA) and Life Cycle Cost (LCC) can contribute to the full assessment of a product or service in the context of sustainable development. The SLCA starts from the stakeholder analysis and definition of social indicators (as: expenses for health, safety or education, work accidents, possibility to organize in Trade unions and so on), and needs to be developed with company’s stakeholder's consensus in order to represent their view. The steps and the processes are the same used for ELCA. The product under study is the NovaLT™16 Gas Turbine, designed and produced by Baker Hughes; a selection of most impacting components has been performed and is reported in Chapter 12 Appendix B.
Nozzles and bucket are the most impacting components in terms of environmental impact, so it was decided to produce them via additive manufacturing (AM) instead of investment casting (IC). As explained in Chapter 5, AM is revolutionizing prototyping production and even small-scale manufacturing. Usually, it is assumed that AM has lower environmental impact, compared to traditional manufacturing processes, but there have been no comprehensive ELCA studies confirming this, especially for the gas turbines and turbomachinery sector. LCA is the methodology applied to compare the environmental and social performance of production of two gas turbine’s components via IC (traditional) or AM (innovative) as detailed in Chapter 6 where five use cases are reported. Comparing the environmental and social performance of innovative technology introduction versus the traditional one (AM vs. IC) to produce a Shroud for Gas Turbine also checking the applicability of human health as an indicator. Then it has been analyzed the environmental and social impact of introducing additive manufacturing for spare parts production developing a survey to involve internal stakeholders in weighting the different indicators. Finally, in Chapter 7 conclusions and suggestions for future development are reported.
From the analysis performed, it has been recognized that:
• the most environmental impacting components of a gas turbines are blades and nozzles (typically made by high alloy metals and produced by investment casting)
• additive manufacturing is in general a good option to reduce environmental and social impact of components traditionally produced via investment casting
• From Social standpoint human health in terms of DALY is a good methodology to quickly evaluate the social impact of a good and alternative design options.
• A detailed Social LCA using SimaPro plus SHDB database can estimate the risks related to good production. This methodology, even if more qualitative respect to the DALY is powerful to assess where the potential hotspots are in terms of supply country and industry sector.
• Cobalt is a very risky hotspot. Reducing its utilization or procuring it from socially responsible mining companies can be a way to reduce risks.
• A new KPI is proposed, avoiding contemplating the cost as it is highly fluctuating, taking in consideration amount of resource used (material and energy)
The variation of Energy, Social risk (or health risk), Raw material amount, and carbon footprint of base and redesigned component, can be used to calculate a single KPI. With this sustainability KPI it is possible to fully compare the different production options.
... This process occurs during the charging of a flywheel energy storage system. The same motor switches to being a generator when it gives out energy from the spinning flywheel to the power system (10). FES systems come in two types: low-speed and high-speed. ...
... The wires will be maintained under superconducting temperature to deplete ohmic losses. The DC current (I) flowing through the coil and the induction of the superconducting coil (L) decides the energy density of SMES (10). It is expressed in the following equation as, High temperature SMES coil can be operated at and at the temperature of, the low temperature SMES can be operated. ...
... Considerable research has been dedicated to exploring various storage technologies and their respective technical characteristics, such as Amirante et al. [8] and Rahman et al. [9]. However, the costs associated with these technologies remain a significant barrier to widespread integration. ...
... The future investment cost development of storage technologies is being calculated using the technological learning approach, employing the input data explained above under Section 2.2 and Equations (5)- (8). The data inputs for learning rate calculations can be found in Tables 3 and 4. ...
... Transitioning the present energy scenario towards utilisation of renewable energy sources would need significant steps towards development of an efficient and sustainable utilisation of energy sources and technologies like fuel cells, air-metal batteries, supercapacitors, and various other electrolyser techniques [1][2][3][4][5][6][7][8]. Amongst all the intuitively researched energy sources, generation of hydrogen from electrolysis of water tends to be extremely favourable pathway. ...
... To determine the electrochemically active surface area (ECSA), the double layer capacitance (C dl ) was calculated at different scan rates by Eqs. (3) and (4). The CVs taken at difference scan rates and their anodic current density has been shown in Figs. ...
... South America and Australia each account for a negligible 0.19% portion, indicating that the development of hydrogen fueling infrastructure is either in its early stages or not a current focus in these areas. For example, ongoing research and development efforts are focused on enhancing electrolyzer technologies [13,14], optimizing compression systems [15], and refining storage solutions [16] to guarantee that HRSs are equipped with cutting-edge technology to facilitate safe and efficient operations. Moreover, the proliferation of HRSs may be seen as a tangible representation of the increasing investment in hydrogen infrastructure by both public and private entities [17]. ...
... The outreach efforts of HRSs further serve to foster the emergence of novel employment prospects, therefore making a valuable contribution to local economies. The emergence of hydrogen fuel as a viable alternative has created For example, ongoing research and development efforts are focused on enhancing electrolyzer technologies [13,14], optimizing compression systems [15], and refining storage solutions [16] to guarantee that HRSs are equipped with cutting-edge technology to facilitate safe and efficient operations. Moreover, the proliferation of HRSs may be seen as a tangible representation of the increasing investment in hydrogen infrastructure by both public and private entities [17]. ...
The present paper offers a thorough examination of the safety measures enforced at hydrogen filling stations, emphasizing their crucial significance in the wider endeavor to advocate for hydrogen as a sustainable and reliable substitute for conventional fuels. The analysis reveals a wide range of crucial safety aspects in hydrogen refueling stations, including regulated hydrogen dispensing, leak detection, accurate hydrogen flow measurement, emergency shutdown systems, fire-suppression mechanisms, hydrogen distribution and pressure management, and appropriate hydrogen storage and cooling for secure refueling operations. The paper therefore explores several aspects, including the sophisticated architecture of hydrogen dispensers, reliable leak-detection systems, emergency shut-off mechanisms, and the implementation of fire-suppression tactics. Furthermore, it emphasizes that the safety and effectiveness of hydrogen filling stations are closely connected to the accuracy in the creation and upkeep of hydrogen dispensers. It highlights the need for materials and systems that can endure severe circumstances of elevated pressure and temperature while maintaining safety. The use of sophisticated leak-detection technology is crucial for rapidly detecting and reducing possible threats, therefore improving the overall safety of these facilities. Moreover, the research elucidates the complexities of emergency shut-off systems and fire-suppression tactics. These components are crucial not just for promptly managing hazards, but also for maintaining the station’s structural soundness in unanticipated circumstances. In addition, the study provides observations about recent technical progress in the industry. These advances effectively tackle current safety obstacles and provide the foundation for future breakthroughs in hydrogen fueling infrastructure. The integration of cutting-edge technology and materials, together with the development of upgraded safety measures, suggests a positive trajectory towards improved efficiency, dependability, and safety in hydrogen refueling stations.
... Hydrogen energy has been regarded as an important clean energy source because of its low pollution, high efficiency, and advantages in terms of sustainable utilization. [1][2][3] The reliability of hydrogen storage and transportation technology is a necessary guarantee for the large-scale application of hydrogen. Under a high-pressure (HP) hydrogen environment (up to 100 MPa), the rubber O-ring seals, one of the critical components in hydrogen refueling, storage, and transportation systems, must face harsh application conditions. ...
As the critical components in hydrogen refueling, storage, and transportation systems, the degradation and failure of rubber O-ring seals under a high-pressure (HP) hydrogen environment (up to 100 MPa) directly affect hydrogen energy safety. Clarifying the interaction mechanism of hydrogen diffusion and the mechanical properties of rubber seals is essential for HP hydrogen infrastructure. A hydrogen diffusion-mechanical sequential numerical model is built to investigate the sealing performance and hydrogen diffusion behaviors of rubber seals using ABAQUS software. The effects of hydrogen swelling environmental pressure (5∼100 MPa) and stress-concentration gradient on mechanical and contact characteristics and hydrogen concentration distribution are analyzed for the rubber seals with/without backup rings, respectively. Furthermore, the orthogonal experimental and comprehensive frequency analysis methods are employed to evaluate the significance of the main structural and assembly parameters and obtain the optimal schemes of the rubber seals under the HP environment. The results show that the stress concentration and rubber extrusion easily occur at the sealing clearance of the O-rings with swelling after pre-compression and pressurization. The hydrogen diffusion of the O-ring is mainly driven by the concentration difference and stress gradient, with the former being the dominant factor. With the increase in the hydrogen pressure, the effective sealing rate along the sealing surface decreases sharply, and the non-uniformity of hydrogen concentration and the possibility of fatigue damage in the rubber O-rings increase. Two multi-objective optimization schemes (Ⅰ and Ⅱ) for the main structural and assembly parameters of rubber seals are obtained by intuitive analysis and comprehensive frequency analysis to improve the extrusion tendency and sealing reliability of rubber seals in the HP hydrogen environment.
... contrast to supercapacitors, the AC grid is used when all energy sources and BSSs are linked, as loads are required [8]. The microgrids may be either direct current (DC) or alternating current (AC), or they might be hybrids of the two. ...
This paper presents a novel approach to electric vehicle (EV) charging infrastructure, integrating solar and wind power with a battery charging station. The system aims to reduce environmental impact and enhance energy resilience while meeting increasing EV charging demands. The Perturb and Observe Maximum Power Point Tracking (MPPT) algorithm optimizes the charging process, extracting maximum power from renewable energy sources. Simulation results show the integrated system consistently achieves high levels of energy harvest from solar and wind sources, ensuring efficient utilization of renewable energy. The system adapts to changing environmental conditions, dynamically adjusting charging parameters to maximize energy capture. Surplus energy stored in station batteries serves as backup power, ensuring uninterrupted EV charging during climate change-induced disruptions. The simulation-based analysis validates the feasibility and efficacy of the proposed integrated approach, underscoring the importance of renewable energy integration and efficient charging algorithms in advancing environmentally friendly transportation solutions.
... These materials, which include improved polymers, high-performance semiconductors, nanostructured catalysts, and next-generation battery components, are now essential for tackling the urgent problems of resilience, sustainability, and energy efficiency. Innovations in solar cells, fuel cells, energy storage systems, and hydrogen production technologies are made possible by their special qualities, which include increased thermal conductivity, high energy density, and improved mechanical strength (Amirante et al., 2017). By concentrating on three main areas: sustainable energy conversion, efficient energy storage, and renewable energy harvesting. ...
... Advances in this technological field have not only significantly improved efficiency and safety standards in the energy sector but have also had a profound impact on the structural transformation of the economy as a whole. Firstly, innovations in gas storage technology have played a central role in improving the efficiency and safety of energy storage [17]. The diversification of natural gas storage methods, such as underground storage (including in the form of salt caverns and depletion fields) and liquefied natural gas (LNG) storage, among others, has not only increased the flexibility to adapt to different geographic and economic conditions but has also significantly improved storage efficiency. ...
As energy demand continues to grow, the enhancement of natural gas storage and peaking capacity has become an important measure to ensure national energy security and to achieve the goals of carbon peaking and carbon neutrality. Gas storage and peaking have mature development models in the international arena, and China is making every effort to develop this system. This study reveals the impact and promotion of natural gas storage and peaking technology on high-quality economic growth in different regional economic environments through sample data from 30 provinces in China, from 2006 to 2022. The results show that natural gas storage and peaking directly promote high-quality economic development and have a positive spatial spillover effect on high-quality development in neighboring regions, a finding verified by the robustness test and endogeneity test. A heterogeneity analysis further revealed that there are significant differences among eastern, central, and western regions in terms of natural gas storage and peaking capacity and quality of economic development. The eastern region has a stronger gas storage and peaking capacity, while the central and western regions have a weaker capacity. Mechanism analysis shows that R and D technology (RDT) efficiency and green finance have a positive moderating effect on the benchmark effect. This has significant implications for policymakers and business leaders, suggesting that peak gas storage and peaking can drive improvements in broader regional corporate sustainability practices and increase regional levels of high-quality development.
... In this context, energy storage plays a pivotal role in ensuring a stable energy supply and mitigating the curtailment of renewable energy (Denholm and Mai, 2019). Common energy storage methods encompass electrochemical storage (e.g., lithium batteries, supercapacitors, and flow batteries), thermal energy storage, compressed air energy storage, flywheel energy storage, pumped hydro storage, and hydrogen (H 2 )-based chemical storage (Amirante et al., 2017;Rahman et al., 2020;Chen et al., 2023;Hou et al., 2024). Among these, H 2 -based chemical storage involves utilizing surplus energy to electrolyze water, yielding H 2 gas, which can either be directly stored or converted into methane (CH 4 ), methanol, ammonia, and other substances for storage or utilization (Glenk and Reichelstein, 2019;Blanco et al., 2020). ...
... [3][4][5] Electrochemical generation of H 2 , a method converting electric energy into highly pure hydrogen, stands out as a promising one among the various methods discovered for hydrogen production. [6,7] The use of a highly effective electrocatalyst is crucial to enable the electrochemical generation of hydrogen. [8,9] Platinum has traditionally served as the benchmark electrocatalyst for the hydrogen evolution reaction due to its low overpotential. ...
Finding the best candidates with outstanding electrocatalytic capabilities for the hydrogen evolution reaction is essential for realizing large‐scale hydrogen production through electrolysis. In this study, we synthesized NiCo2Se4 (NCS) and NiTe2 (NT) nanorod arrays using a hydrothermal method. The confirmation of catalyst formation was achieved through X‐ray diffraction analysis, electron microscopy imaging, and X‐ray photoelectron spectroscopy. Leveraging the plentiful heterointerfaces and synergistic effects arising from the incorporation of bimetallic components, the NCS/NT electrocatalyst demonstrates remarkable efficacy in catalyzing the hydrogen evolution reaction. It achieves a minimal overpotential of 163 mV to attain a current density of 50 mA cm⁻², showcasing exceptional catalytic activity. Further exploration has revealed that the engineering of heterogeneous interfaces and the morphology of nanorods not only guarantee the exposure of numerous active sites and expedite electron‐mass transfer but also trigger electron modulation. Such modulation serves to fine‐tune the adsorptive and desorptive dynamics of reaction intermediates, culminating in an enhancement of the catalyst's inherent activity. This study illuminates the novel composite electrocatalyst with robust synergy, highlighting the pivotal role of their unique nanostructures in achieving high‐efficiency hydrogen production via electrolysis.
... Currently, it has been proven that PHES is an effective and attractive storage solution with fast response times and long lifetimes [7][8][9]. PHES systems store and generate electricity by exchanging water between reservoirs at different altitudes. They convert potential energy to electrical energy and vice versa, allowing for water to flow from a high altitude or by pumping water from a low altitude to a higher altitude. ...
In this paper, analyses of Francis turbine failures for powerful Pumped Hydraulic Energy Storage (PHES) are conducted. The structure is part of PHES Chaira, Bulgaria (HA4—Hydro-Aggregate 4). The aim of the study is to assess the structure-to-concrete embedding to determine the possible causes of damage and destruction of the HA4 Francis spiral casing units. The embedding methods that have been applied in practice for decades are discussed and compared to those used for HA4. A virtual prototype is built based on the finite-element method to clarify the influence of workloads under the generator mode. The stages of the simulation include structural analysis of the spiral casing and concrete under load in generator mode, as well as structural analysis of the spiral casing under loads in generator mode without concrete. Both simulations are of major importance. Since the failure of the surface between the turbine, the spiral casing, and the concrete is observed, the effect of the growing contact gap (no contact) is analyzed. The stresses, strains, and displacements of the turbine units are simulated, followed by an analysis for reliability. The conclusions reveal the possible reasons for cracks and destruction in the main elements of the structure.
... El cambio climático, impulsado en gran medida por las emisiones de gases de efecto invernadero provenientes de la quema de combustibles fósiles, ha acelerado la necesidad de adoptar fuentes de energía renovable a gran escala [1]. Sin embargo, la naturaleza intermitente y variable de las principales fuentes de energía renovable, como la solar y la eólica, presenta desafíos significativos para su integración efectiva en las redes eléctricas existentes [2]. ...
Este estudio analizó las tecnologías de almacenamiento de energía y su papel en la mejora de la gestión de energías renovables. Se examinaron diversas tecnologías, incluyendo baterías de iones de litio, plomo-ácido, flujo redox, aire comprimido y volantes de inercia, comparando sus características técnicas y económicas. La investigación reveló un creciente interés en baterías de iones de litio y almacenamiento de hidrógeno, con aplicaciones que abarcaron desde la integración de energía solar y eólica hasta la estabilización de la red y la gestión de la demanda. Se identificaron estrategias de optimización clave, como algoritmos de control predictivo, técnicas de inteligencia artificial y métodos de optimización estocástica. Los resultados subrayaron la diversidad y complementariedad de las tecnologías de almacenamiento, destacando su importancia en la transición hacia un sistema energético sostenible. El estudio concluyó que, aunque persisten desafíos en costos y escalabilidad, el almacenamiento de energía es vital para la integración efectiva de energías renovables, requiriendo un enfoque holístico que considere aspectos tecnológicos, económicos y regulatorios para su implementación exitosa.
... Most of these renewable energy sources, especially wind and solar, suffer from intermittency, resulting in low reliability for providing a steady energy supply [26]. To overcome this disadvantage and enhance energy utilization efficiency, energy storage which refers to capturing the excess energy produced at one time and temporarily storing it for use at a later time, is an inevitable requirement [27][28][29]. The most common way currently to store energy is to store the energy in its original form, such as coal, crude oil, and natural gas. ...
... Nowadays it is proven that PHES is effective and attractive storage with fast response times and long lifetimes [7][8][9]. The PHES systems store and generate electricity by exchanging water between reservoirs at different altitudes. ...
In the paper analyzes of Francis turbine failures for a powerful Pumped Hydraulic Energy Storage (PHES) are conducted. The structure is part of the PHES Chaira, Bulgaria (HA4 - Hydro-Aggregate 4). The aim is assessment of the structure-to-concrete embedment for possible cause of damages and destructions of the HA4 Francis spiral casing units. The embedment methods applied in the practice for decades are discussed and compared to that used for HA4. An innovative virtual prototype is built based on the finite element method to clarify the influence of workloads under generator mode. The stages of the simulation include:- complete structural analysis of the spiral case and the concrete under loads in generator mode;- complete structural analysis of the spiral case under loads in generator mode but without the concrete.Both procedures of simulations (with and without the concrete) are of major importance. Since a failure of the surface between the turbine, the spiral case and the concrete is observed the effect of the increasing contact gap (no contact) is analyzed. The stresses, strains and displacements of the turbine units are simulated followed by important analysis for reliability. The conclusions reveal the possible reasons for cracks and destruction in the main elements of the structure.
... In this era of evolution, where the world's population is snowballing, it ultimately results in a prevailing energy crisis. Industrial development is regarded as a source of economic growth in contemporary economies so conventional energy resources are depleting [1]. Despite their drawbacks, fossil fuels serve as the main contributory factor to global warming as they are still considered the chief energy source [2]. ...
This research exhaustively inquired about the structural, photocatalytic, mechanical, and optoelectronic characteristics of the cubic perovskite CsSrO3−x Hx with the CASTEP code’s implementation of the GGA-PBE formalism. It aims to examine the characteristics of CsSrO3−xHx cubic perovskite with varied concentrations of substituents (x = 0, 0.3, 0.6, 0.9, 1.2, 1.5, 1.8, 2.1, 2.4, 2.7, and 3.0). The stability and synthesizability of the compound are guaranteed by the values of elastic constants and negative formation enthalpies. As H-insertion increases, there are variations in the values of anisotropy and elastic moduli. A semiconductor’s wide bandgap narrows as dopant concentration rises, changing its nature from indirect to direct. The findings imply that the compound’s electronic characteristics can be altered through the application of dopants, rendering them appropriate for a range of optoelectronic uses. The inclusion of hydrogen caused the structural change from cubic to tetragonal and orthorhombic. The distortion caused the lattice parameters to vary in values. Tolerance factor lies in range of 0.7–1 that ensures structural stability of CsSrO3−x Hx. Our computed results reveal the anisotropic nature of our compound. The obtained bandgap for CsSrO3−xHx indicates that both O2 evolution and H2 reduction are allowed since the requisite redox potentials are satisfied. Photocatalytic properties of CsSrO2.4H0.6 reveals that it is the best doped system as a potential candidate for water-splitting photocatalysis, as it has equal effectiveness to both oxidation and reduction processes. The bandgap was shown to decrease from 5.33 eV to 2.812 eV at complete hydrogen insertion, which also had an impact on the material’s optoelectronic characteristics. All the optical considerations such as dielectric functions, refractive indices, extinction coefficients, optical reflectivity, absorption coefficients, and loss functions are also thoroughly explained. The material exhibits mechanical stability along with ionic and covalent bonding.
... Tese electrolytes are herein discussed. Figure 9: Te SMES operating assembly [99]. ...
Energy storage is a more sustainable choice to meet net-zero carbon foot print and decarbonization of the environment in the pursuit of an energy independent future, green energy transition, and uptake. The journey to reduced greenhouse gas emissions, increased grid stability and reliability, and improved green energy access and security are the result of innovation in energy storage systems. Renewable energy sources are fundamentally intermittent, which means they rely on the availability of natural resources like the sun and wind rather than continuously producing energy. Due to its ability to address the inherent intermittency of renewable energy sources, manage peak demand, enhance grid stability and reliability, and make it possible to integrate small-scale renewable energy systems into the grid, energy storage is essential for the continued development of renewable energy sources and the decentralization of energy generation. Accordingly, the development of an effective energy storage system has been prompted by the demand for unlimited supply of energy, primarily through harnessing of solar, chemical, and mechanical energy. Nonetheless, in order to achieve green energy transition and mitigate climate risks resulting from the use of fossil-based fuels, robust energy storage systems are necessary. Herein, the need for better, more effective energy storage devices such as batteries, supercapacitors, and bio-batteries is critically reviewed. Due to their low maintenance needs, supercapacitors are the devices of choice for energy storage in renewable energy producing facilities, most notably in harnessing wind energy. Moreover, supercapacitors possess robust charging and discharging cycles, high power density, low maintenance requirements, extended lifespan, and are environmentally friendly. On the other hand, combining aluminum with nonaqueous charge storage materials such as conductive polymers to make use of each material’s unique capabilities could be crucial for continued development of robust storage batteries. In general, energy density is a key component in battery development, and scientists are constantly developing new methods and technologies to make existing batteries more energy proficient and safe. This will make it possible to design energy storage devices that are more powerful and lighter for a range of applications. When there is an imbalance between supply and demand, energy storage systems (ESS) offer a way of increasing the effectiveness of electrical systems. They also play a central role in enhancing the reliability and excellence of electrical networks that can also be deployed in off-grid localities.
... Hydrogen as an abundantly available energy source with zero pollution has received significant recognition as an important sustainable energy source in the 21st energy century from various countries [4]. Owing to its unique advantages of low energy consumption for compressed hydrogen production, fast charging/discharging rate, etc. [5], great commercial application prospects of hydrogen have already emerged in the energy sector, for example, in fuel cell vehicles (FCVs) and hydrogen fuel stations (HFSs) [6][7][8]. Furthermore, the recent advancements in the development of hydrogen storage technology, efficient ways of generating green hydrogen and the reduced cost of delivery of hydrogen to the end user, demonstrate every potential of this fuel to become the mainstream energy carrier in the coming decades [9]. ...
... The main function of ESSs is to capture energy from many RE systems, transform it and store it for a variety of uses. Numerous authors have studied ESSs from different perspectives [3][4][5][6]. An extensive analysis is carried out by [7] regarding the crucial function of energy storage technologies in power systems, with a particular focus on solar integration in the context of Malaysia. ...
Integrating renewable energy systems into the grid has various difficulties, especially in terms of reliability, stability, and adequate operation. To control unpredictable loads, one potential approach is to incorporate energy storage systems (ESSs) into the power network. The implementation of an ESS is dependent on its technical properties, the implementation site, the electrical energy source (conventional or renewable energy types), and its related costs. Therefore, an up-to-date database with technical and economic properties, cost data, and applications is necessary for decision-making purposes. Moreover, the integration of ESSs with renewables should be based on an optimal sizing analysis that incorporates system modeling and proper formulations of technical and financial design criteria. This paper provides an overview of recent developments in the field of energy storage; combining a comprehensive assessment of the technical and economic characteristics of the various types of energy storage systems, and creating a pertinent database with the technical specifications and cost figures of both established and newly developed energy storage systems. The reviewed research works present all metrics that affect the performance of each type of storage and discuss their future directives and innovations. Moreover, recent analyses of integrating energy storage systems with hybrid photovoltaic/wind power systems are also discussed in terms of system modeling, performance analysis indicators, and optimization methods. By combining all these aspects, our research significantly contributes to the existing literature and offers a holistic understanding of energy storage systems and their role in hybrid power plant applications.
... Large-scale energy storage has become necessary for power systems' safe and stable operation to suppress the volatility of wind and photovoltaic power [5,[9][10][11]. By 2022, pumped storage will account for 90% of the total installed energy storage, and lithium-ion batteries will dominate the new installations. However, the application of pumped storage is restrained by geographical conditions, while lithium-ion batteries' service life, safety, and pollution issues still hinder its largescale application [1,[12][13][14][15][16][17][18][19][20]. ...
This paper presents the first systematic study on power control strategies for Modular-Gravity Energy Storage (M-GES), a novel, high-performance, large-scale energy storage technology with significant research and application potential. Addressing the current research gap in M-GES power control technology, we propose two corresponding compensation modes and several power control strategies for Hybrid M-GES and M-GES. The effectiveness of these strategies is validated through simulations on the MATLAB/Simulink platform, including tests using sinusoidal power and feasibility verification based on a natural California load curve. Additionally, we analyze the normal and abnormal operating conditions of M-GES. In conclusion, the characteristics of the proposed control strategies are summarized, providing a guideline for further research.
The rapid growth of the transportation sector in the past few decades has contributed significantly to global warming issues, leading to extensive research on vehicles having nearly zero or total zero tailpipe carbon emissions. The automobiles within this classification belong to hybrid electrical vehicles (HEVs), plug‐in HEVs, battery–electric vehicles (BEVs), fuel‐cell (FC) EVs (FCEVs), and FC HEVs. FCHEVs are powered by a combination of FC systems, rechargeable batteries, ultracapacitors, and/or mechanical flywheels. FC technology appears to hold potential in terms of extended driving distances and quicker refueling times for vehicles that emit no exhaust fumes. A significant number of research studies have examined various types of energy‐storage devices as vehicle power supply, their interfacing with the drive mechanism using power converters and their energy management strategies (EMS). In this article, various EMS for FC‐based EVs are discussed. Classifications of FCEVs, BEVs, and EMSs for FCHEVs are developed by various researchers. In this review report, it is indicated that the existing EMS are capable of performing well, yet further research is required for better reliability and intelligence toward achieving greater fuel efficiency and lifetime of upcoming FCHEVs.
As an important part of the power industry, carbon reduction technology in substations plays a key role in supporting the implementation of national policy of carbon peak and reduction. In recent years, a series of carbon emission reduction measures have been developed in the operation phase of substations and promoted beneficial carbon emission reduction. This article summarizes the progress of related technologies and applications from the aspects of substation composition, carbon emission sources, carbon emission reduction technologies, and their effects. Firstly, the composition of carbon emissions from substations during operation is described. Secondly, various measures for carbon emission reduction are reviewed, including the selection of substation equipment types, the intelligent management of substation equipment, and the use of renewable energy. Finally, future technological directions for carbon reduction in substations are discussed, providing technical references and guidance for the sustainable construction and development of low-carbon substations.
The increased requirements for high-efficiency and low-cost energy storage devices have paced research nowadays. The present study explores the applications of reduced Graphene Oxide (rGO) and Polyaniline (Pani) composites (rGO-Pani) for supercapacitor devices. These composites offer improved electrical conductivity and high specific capacitance. The composites have been characterized for their optical, magnetic, and specific capacitance properties. The energy band gap and Urbach’s energy for the composites is observed to be lower than the pristine Pani sample. Three photoluminescence peaks have been observed for pristine Pani whose intensity increases with increasing concentration of rGO in the composite. The CIE coordinates also indicate the higher color temperature of the composites. The original samples of rGO and Polyaniline do not possess any magnetic properties, but the composites show slight retentivity and coercivity. Cyclic voltammetry and Galvanostatic Charge-Discharge techniques performed at different scan rates reveal higher specific capacitance for Polyaniline samples than the composites that may be attributed to the presence of defects or impurities as they can introduce additional energy levels within the band structure. Deep-level defects may trap charge carriers, which leads to reduced charge transport efficiency and lower electrochemical performance.
A novel compressed air energy storage (CAES) system utilizing a dual-purpose compressor equipped with a water spray cooling function has been proposed. The dual-purpose compressor integrates both compression and expansion functions. It utilizes saturated compressed air to facilitate the storage and release of compressed air energy in abandoned oil wells, while simultaneously enhancing residual tail oil recovery. A comprehensive thermodynamic model was developed to assess the effects of various parameters, such as the compression ratio, the mass flow of water vapor injection, and the mass flow of compressed air, on the power consumption of the compressors. The water spray cooling function was utilized to control the compression work and regulate the outlet temperature. Meanwhile, the outlet pressures were determined based on the depth of the abandoned oil well. The results indicate that the comprehensive energy utilization efficiency (ηCEUE) of the compressed air energy storage system can reach 81.82 % under the conditions of an ambient temperature of 25 °C, an outlet pressure of 11 MPa, and an outlet temperature of 290 °C. When the expansion power of one cycle is 3.68 MWh and the heat storage capacity is 24.1 GJ·h−1, the minimum simple payback period (SPP) can be achieved in 5.74 years. This study establishes a foundation for the utilization of abandoned oil wells, and offers a novel approach for the engineering application of a compressed air energy storage system, which is based on a dual-purpose compressor with compression and expansion, integrated with a water spray cooling function.
As the world’s demand for sustainable and reliable energy source intensifies, the need for efficient energy storage systems has become increasingly critical to ensuring a reliable energy supply, especially given the intermittent nature of renewable sources. There exist several energy storage methods, and this paper reviews and addresses their growing requirements. In this paper, the energy storage options are subdivided according to their primary discipline, including electrical, mechanical, thermal, and chemical. Different possible options for energy storage under each discipline have been assessed and analyzed, and based on these options, a handsome discussion has been made analyzing these technologies in the hybrid mode for efficient and reliable operation, their advantages, and their limitations. Moreover, combinations of each storage element, hybrid energy storage systems (HESSs), are systems that combine the characteristics of different storage elements for fulfilling the gap between energy supply and demand. HESSs for different storage systems such as pumped hydro storage (PHS), battery bank (BB), compressed air energy storage (CAES), flywheel energy storage system (FESS), supercapacitor, superconducting magnetic coil, and hydrogen storage are reviewed to view the possibilities for hybrid storage that may help to make more stable energy systems in the future. This review of combinations of different storage elements is made based on the previous literature. Moreover, it is assessed that sodium-sulfur batteries, lithium-ion batteries, and advanced batteries are the most helpful element in HESSs, as they can be hybridized with different storage elements to fulfill electricity needs. The results also show that HESSs outperformed other storage systems and, hence, hybridizing the characteristics of different storage elements can be employed for optimizing the performance of energy storage systems.
The research on energy storage resource management is an important measure to cope with the present problem of uncertainty in the use of renewable energy, in order to explore the evolution of the research focus and future trend of energy storage resource management under the uncertainty of renewable energy, this paper adopts the method of bibliometric analysis, and conducts a visual analysis of the relevant 800 documents in the core collection of the Web of Science by using the CiteSpace to draw co-occurrence maps and analyze the collaborative networks of different countries/regions, institutions and authors in this field, and further conducted journal co-citation analysis, literature co-citation analysis and author co-citation analysis. The keyword co-occurrence, emergent analysis, and cluster co-occurrence analysis reveal the current research focus and trend in this field, and summarize and propose four future key focus directions: energy storage technology improvement, energy storage system integration, expansion of business models for energy storage resource management, and intelligent control of energy storage system, which provide new research paths for solving the problem of renewable energy uncertainty in the future.
Development and application of large‐scale energy storage systems are surging due to the increasing proportion of intermittent renewable energy sources in the global energy mix. Redox flow batteries are prime candidates for large‐scale energy storage due to their modular design and scalability, flexible operation, and ability to decouple energy and power. To date, several different redox couples are exploited in redox‐flow batteries; some are already commercialized. This battery technology is facing a lot of challenges in the science, engineering, and economic front. Issues plaguing flow batteries are low energy density, high overall cost, poor stability of electrolytes, shifting of solvent from anolyte to catholyte while using cation exchange membrane, reverse flow with anion exchange membrane, and corrosion of graphite felt in the catholyte side. Significant research efforts are ongoing to address these challenges. This comprehensive and critical review summarizes the recent progress in electrolyte technologies, including electrochemical performance and stability, strategies to enhance the energy and power densities and, in the end, the levelized and life‐cycle cost of these batteries analyzed. A comprehensive outlook on this technology with respect to practical energy storage applications is also provided.
The Tibetan Plateau is characterized by abundant solar energy resources, providing excellent conditions for centralized solar photovoltaic power generation applications. Traditionally, the electricity generated by photovoltaic systems is mainly utilized through grid connections or battery storage. However, constrained by grid standards and regional dispatching, power surplus waste is common in high-altitude areas. In this regard, integrating storage systems are generally accompanied by increased costs. To address this, an innovative regional photovoltaic residual electricity thermal energy conversion and storage system is proposed and evaluated in this paper. A system simulation model is developed in Trnsys, and the load characteristics of surplus electricity are simulated and evaluated under different photovoltaic capacities. On this basis, the heat storage system capacity is obtained. The simulation results showed that the energy utilization rate of the system increased relatively by 6% to 54%, with the exergy efficiency in the range of 12.55%–23.56%, when implementing the proposed solution. The levelized cost of energy exhibited a trend of initially decreasing and then increasing. Furthermore, a performance comparison was conducted against traditional photovoltaic systems and solar centralized heating systems. The proposed system's operational benefits and investment costs are evaluated and analyzed. The results highlighted that the system not only effectively utilizes the abundant solar energy resources in the Tibetan Plateau, realizing efficient energy conversion and storage, but also demonstrates significant economic and environmental benefits. And the findings of this study contribute to the efficient utilization of solar energy resources in the Tibetan Plateau.
This investigation examines the underground storage of hydrogen in a variety of storage types, including caverns (salt and rock), depleted oil and natural gas reservoirs, and aquifers. It presents a roadmap for the execution of subsurface hydrogen storage. The cost-effectiveness of hydrogen production remains a significant determinant for its large-scale adoption. In its storage, a multitude of challenges and obstacles can arise and they are presented in this paper. It was observed that some characteristics of hydrogen must be sufficiently managed to
ensure air tightness during its subsurface storage, migration, and withdrawal. The selection of geological formations for underground hydrogen storage should rely on a comprehensive geological assessment, including engineering factors. If there is any chance of hydrogen gas escaping from an underground storage facility beyond
its defined boundaries, the location should be deemed unsafe and discarded. In addition, prior to the full-scale implementation of underground hydrogen storage (UHS), different obstacles in all aspects of regulations, geology, technology, and economics need to be tackled and resolved. Due to the intricate nature of the problem and the relatively limited expertise in this sort of operation, it is anticipated that an extended period of research will be necessary. Also, before any future implementations can occur, thorough investigations must be conducted to gain a deeper understanding of the mechanisms involved in hydrogen interaction with surrounding rocks and installations. Preparations should be made to mitigate all potential risks. These activities should be carried out within clearly specified time intervals.
Lamina and laminate mechanical properties of materials suitable for flywheel high-speed energy storage were investigated. Low density, low modulus and high strength composite material properties were implemented for the constant stress portion of the flywheel while higher density, higher modulus and strength were implemented for the constant thickness portion of the flywheel. Design and stress analysis were used to determine the maximum energy densities and shape factors for the flywheel. Analytical studies along with the use of the CADEC-online software were used to evaluate the lamina and laminate properties. This study found that a hybrid composite of M46J/epoxy–T1000G/epoxy for the flywheel exhibits a higher energy density when compared to known existing flywheel hybrid composite materials such as boron/epoxy–graphite/epoxy. Results from this study will contribute to further development of the flywheel that has recently re-emerged as a promising application for energy storage due to significant improvements in composite materials and technology.
This paper presents the development of a rule-based energy management control strategy suitable for isolated diesel power-plants equipped with a battery energy storage system for peak load shaving. The proposed control strategy includes the generator scheduling strategy and peak load leveling scheme based on current microgrid active and reactive power requirements. In order to investigate the potentials for fuel expenditure reduction, 30 days-worth of microgrid power flow data has been collected on an isolated land-based oil drilling rig powered by a diesel generator power-plant, characterized by highly-variable active and reactive load profiles due to intermittent engagements and disengagements of high-power electric machinery such as top-drive, draw-works and mud-pump motors. The analysis has indicated that by avoiding the low-power operation of individual generators and by providing the peak power requirements (peak shaving) from a dedicated energy storage system, the power-plant fuel efficiency may be notably improved. An averaged power flow simulation model has been built, comprising the proposed rule-based power flow control strategy and the averaged model of a suitably sized battery energy storage system equipped with grid-tied power converter and state-of-charge control system. The effectiveness of the proposed rule-based strategy has been evaluated by means of computer simulation analysis based on drilling rig microgrid active and reactive power data recorded during the 30 day period. The analysis has indicated that fuel consumption of thus modified drilling rig diesel generator power-plant can be reduced by about 12% compared to current practice in the field relying on human operator-based decision making, which would also result in proportional reduction of carbon-dioxide emissions. Finally, the analysis has also shown that the return-of-investment period for the considered battery energy storage system might be between one and two years depending on the power-plant utilization (duty) ratio.
Due to the new challenge of meeting number-based regulations for particulate matter (PM), a numerical and experimental study has been conducted to better understand particulate formation in engines fuelled with compressed natural gas. The study has been conducted on a Heavy-Duty, Euro VI, 4-cylinder, spark ignited engine, with multipoint sequential phased injection and stoichiometric combustion. For the experimental measurements two different instruments were used: a condensation particle counter (CPC) and a fast-response particle size spectrometer (DMS) the latter able also to provide a particle size distribution of the measured particles in the range from 5 to 1000 nm. Experimental measurements in both stationary and transient conditions were carried out. The data using the World Harmonized Transient Cycle (WHTC) were useful to detect which operating conditions lead to high numbers of particles. Then a further transient test was used for a more detailed and deeper analysis. Finally 3-D Computational Fluid Dynamics (CFD) simulations were performed and the numerical results obtained were compared to particle size distributions (PSDs) derived from the experimental measurements carried out in stationary conditions. In this way the influences of engine load and regime on particle size distribution (PSD) were determined. A semi-detailed soot model and a chemical kinetic model, including poly-aromatic hydrocarbon (PAH) formation, were coupled with a spark ignition model and the G equation flame propagation model for the SI engine simulations and for predictions of soot mass and particulate number density. Qualitative agreements of in-cylinder particle distributions were obtained and results are helpful to understand particulate formation processes.
This paper presents an integrated modelling methodology which includes reduced-order models of a lithium ion battery and a power electronic converter, connected to a 35-bus distribution network model. The literature contains many examples of isolated modelling of individual energy storage mediums, power electronic interfaces and control algorithms for energy storage. However, when assessing the performance of a complete energy storage system, the interaction between components gives rise to a range of phenomena that are difficult to quantify if studied in isolation. This paper proposes an integrated electro–thermo–chemical modelling methodology that seeks to address this problem directly by integrating reduced-order models of battery cell chemistry, power electronic circuits and grid operation into a computationally efficient framework. The framework is capable of simulation speeds over 100 times faster than real-time and captures phenomena typically not observed in simpler battery and power converter models or non-integrated frameworks. All simulations are performed using real system load profiles recorded in the United Kingdom. To illustrate the advantages inherent in such a modelling approach, two specific interconnected effects are investigated: the effect of the choice of battery float state-of-charge on overall system efficiency and the rate of battery degradation (capacity/power fade). Higher state-of-charge operation offers improved efficiency due to lower polarisation losses of the battery and lower losses in the converter, however, an increase in the rate of battery degradation is observed due to the accelerated growth of the solid-electrolyte interphase layer. We demonstrate that grid control objectives can be met in several different ways, but that the choices made can result in a substantial improvement in system roundtrip efficiency, with up to a 43% reduction in losses, or reduction in battery degradation by a factor of two, depending on battery system use case.
Due to the capricious nature of renewable energy resources, such as wind and solar, large-scale energy storage devices are increasingly required to make the best use of the renewable power. The redox flow battery is considered suitable for large-scale applications due to its modular design, good scalability and flexible operation. The biggest challenge of the redox flow battery is the low energy density. The redox active species is the most important component in redox flow batteries, and the redox potential and solubility of redox species dictate the system energy density. This review is focused on the recent development of redox species. Different categories of redox species, including simple inorganic ions, metal complexes, metal-free organic compounds, polysulfide/sulfur and lithium storage active materials, are reviewed. The future development of redox species towards higher energy density is also suggested.
In this study, we investigate the mass transport effects of various flow field designs paired with raw and laser perforated carbon paper electrodes in redox flow batteries (RFBs). Previously, we observed significant increases in peak power density and limiting current density when perforated electrodes were used in conjunction with the serpentine flow field. In this work, we expand on our earlier findings by investigating various flow field designs (e.g., serpentine, parallel, interdigitated, and spiral), and continuously measuring pressure drop in each configuration. In all cases, these perforated electrodes are found to be associated with a reduction in pressure drop from 4% to 18%. Flow field designs with a continuous path from inlet to outlet (i.e., serpentine, parallel, spiral) are observed to exhibit improved performance (up to 31%) when paired with perforated electrodes, as a result of more facile reactant delivery and resulting greater utilization of the available surface area. Conversely, flow fields with discontinuous paths which force electrolyte to travel through the electrode (e.g. interdigitated), are adversely affected by the creation of perforations due to the high permeability 'channels' in the electrode. These results demonstrate that mass transport can significantly limit the performance of RFBs with carbon paper electrodes.
The hydrogen accumulation in metal hydrides is the urgent problem of hydrogen power engineering and the demand for metal hydrides as capacitive, safe and convenient in service sources of hydrogen has stimulated the study of hydrogen capacity of multicomponent alloys. In recent years, much attention has been given by scientists to the investigation of hydrogen-sorption and desorption properties of different materials, including nanocarbon structures and composites on their base, the study of peculiarities of the reversible hydrogen interaction with hydride forming metals and alloys, the development of high-pure hydrogen storage and transportation in solids. The present work is devoted to the development and methodology of selection of the chemical composition of metal hydride alloy for hydrogen accumulators.
http://aheu.com.ua/;
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http://ichms.org/.
In this work, we report on the performance of Diels Alder poly(phenylene) membranes in vanadium redox flow batteries. The membranes were functionalized with quaternary ammonium groups to form an anion exchange membrane (QDAPP) and with sulfonic acid groups to form a cation exchange membrane (SDAPP). Both membrane classes showed similar conductivities in the battery environment, suggesting that the ion conduction mechanism in the material is not strongly affected by the moieties along the polymer backbone. The resistance to vanadium permeation in QDAPP was not improved relative to SDAPP, further suggesting that the polarity of the functional groups do not play a significant role in the membrane materials tested. Both QDAPP and SDAPP outperformed Nafion membranes in cycling tests, with both achieving voltage efficiencies above 85% while maintaining 95% coulombic efficiency while at a current density of 200 mA/cm2.
Lithium-sulfur cells present an attractive alternative to Li-ion batteries due to their large energy density, safety, and possible low cost. Their successful commercialisation is dependent on improving their performance, but also on acquiring sufficient understanding of the underlying mechanisms to allow for the development of predictive models for operational cells. To address the latter, we present a zero dimensional model that predicts many of the features observed in the behaviour of a lithium-sulfur cell during charge and discharge. The model accounts for two electrochemical reactions via the Nernst formulation, power limitations through Butler-Volmer kinetics, and precipitation/dissolution of one species, including nucleation. It is shown that the flat shape of the low voltage plateau typical of the lithium-sulfur cell discharge is caused by precipitation. During charge, it is predicted that the dissolution can act as a bottleneck, because for large enough currents the amount that dissolves becomes limited. This results in reduced charge capacity and an earlier onset of the high plateau reaction, such that the two voltage plateaus merge. By including these effects, the model improves on the existing zero dimensional models, while requiring considerably fewer input parameters and computational resources than one dimensional models. The model also predicts that, due to precipitation, the customary way of experimentally obtaining the open circuit voltage from a low rate discharge might not be suitable for lithium-sulfur. This model can provide the basis for mechanistic studies, identification of dominant effects in a real cell, predictions of operational behaviour under realistic loads, and control algorithms for applications.
The aim of this paper is to propose an effective technique which employs a proportional-integral Fuzzy logic controller for the thrust regulation of small scale turbojet engines, capable of ensuring high performance in terms of response speed, precision and stability. Fuzzy rules have been chosen by logical deduction and some specific parameters of the closed loop control have been optimized using a numerical simulator, so as to achieve rapidity and stability of response, as well as absence of overshoots. The proposed Fuzzy logic controller has been tested on the Pegasus MK3 microturbine: the high response speed and precision of the proposed thrust control, revealed by the simulations, have been confirmed by several experimental tests with step response. Its stability has been demonstrated by means of the frequency response analysis of the system. The proposed thrust control technique has general validity and can be applied to any small-scale turbojet engine, as well as to microturbines for electricity production, provided that thrust being substituted with the net mechanical power.
The novel and efficient electrode materials have been developed for supercapacitor applications based on carbon fiber fabric/MnO2 hybrid materials, in which MnO2 was uniformly coated on the surface of carbon fiber fabric (CFF). A green hybrothermal method was used to functionalize CFF with coral-like MnO2 nanostructures to improve the pseudocapacitance properties of the hybrid composites. These CFF/MnO2 composites are used as excellent flexible electrodes for high-performance electrochemical supercapacitors applications. The morphological, structural and crystalline properties of composites were analysed by using various techniques such as FE-SEM, XRD, XPS, and Raman spectroscopy, respectively. The electrochemical performance was examined by cyclic voltammetry (CV), galvanostatic charge-discharge tests and electrochemical impedance spectroscopy (EIS). In a three-electrode system, the CV tests reveal the superior specific capacitance of 467 F/g at a current density of 1 A/g with capacitance retention of 99.7% and the columbic efficiency remains as high as 99.3% after 5000 cycles, demonstrating an outstanding electrochemical cyclic stability. In addition, high-performance device fabricated with CFF/MnO2 demonstrated excellent energy density of 20 Wh/kg at a power density of 0.175 kWh/kg. These novel electrode materials could be potential candidate for applications in practical and large-scale energy storage systems.
Renewable energy systems are proving to be promising and environment friendly sources of electricity generation, particularly, in countries with inadequate fossil fuel resources. In recent years, wind, solar photovoltaic (PV) and biomass based systems have been drawing more attention to provide electricity to isolated or energy deficient regions. This paper presents a hybrid PV-wind generation system along with biomass and storage to fulfill the electrical load demand of a small area. For optimal sizing of components, a recently introduced swarm based artificial bee colony (ABC) algorithm is applied. To verify the strength of the proposed technique, the results are compared with the results obtained from the standard software tool, hybrid optimization model for electric renewable (HOMER) and particle swarm optimization (PSO) algorithm. It has been verified from the results that the ABC algorithm has good convergence property and ability to provide good quality results. Further, for critical case such as the failure of any source, the behavior of the proposed system has been observed. It is evident from the results that the proposed scheme is able to manage a smooth power flow with the same optimal configuration.
In this article presents two techniques of commands DTC (direct torque control) and DPC (direct power control) applied in the system of converting wind energy with storage. The wind generator used is based on a double fed induction generator (DFIG) where the stator is linked directly with the network and the rotor is connected to the network through the power converter. The flywheel energy storage system (FESS) based on a flywheel, an induction machine (IM) and an electronic power converter is associated with the wind generator via the DC bus. The two converters side DFIG and the (FESS) are controlled by the DTC. The three-level converter side electricity grid which ensures constant DC bus voltage is controlled by the DPC, in order to mitigate the wave quality problems. In the literature, this control strategy has been frequently used for the two levels converter. The direct control of these systems has a purpose of eliminating the block of pulse width modulation and loops of regulations internal controlled variables, which gives a faster response. The use of switching table makes the system more efficient from the technical and economic view. A maximum power tracking technique «Maximum Power Point Tracking» (MPPT) and a pitch angle control strategy are presented. The model of the complete system is developed in Matlab/Simulink/to analyze from the simulation results the integration of wind chain to electric networks.
The present work is focused on the demonstration of an innovative approach to a superconducting magnetic energy storage system by means of next generation superconducting wires. The device is thought to be integrated in a more complex biomass plant for green energy production which includes an anaerobic digester and a cogenerator for biogas and electrical energy production. Presented technology allows the storage of the green energy produced with a very high efficiency and with a better power quality respect to traditional counterparts.
In this article, we present two techniques of commands DTC (direct torque control) and DPC (direct power control), applied to in the system for converting wind energy with storage. The use of the wind generator is based on a double fed induction Generator (DFIG) where the stator is connected directly to the network and the rotor is connected to the network through the power converter. The Flywheel Energy Storage System (FESS) based on a flywheel, an induction machine (IM) and an electronic power converter is associated with the wind generator via the DC bus. The two converters side DFIG and the (FESS) are controlled by the DTC. The three-level converter side electricity grid which ensures constant DC bus voltage is controlled by the DPC. In the literature, this control strategy has been frequently used for the two levels converter. The direct control of these systems has purpose to eliminate the block of pulse width modulation and loops of regulations internal controlled variables. The use of switching table makes the system more efficient from the technical and economic view.
Energy storage systems are important for dealing with the fluctuation of renewable energies in course of their increasing penetration into the energy market. Small-scale compressed air energy storage (CAES) with artificial air vessels can improve the supply capacity of power system and the utilization of renewable energy by storing excess power during off-peak time and releasing it for on-peak power supply and becomes more promising for distributed energy systems. For diabatic CAES, heat usually cannot be efficiently utilized and the low inlet temperature of turbine in an adiabatic-CAES (A-CAES) usually leads to low discharge efficiency. To address these problems, in this paper, we propose a novel combined cooling, heating and power system (CCHP) based on small-scale CAES. The sensitivity analysis performed shows the effectiveness of heat exchanger, and the air temperature and pressure at the turbine inlet have great influence on the system’s thermodynamic performance. Then, the trade-off between the thermodynamic and economic performances is investigated by an evolutionary multi-objective algorithm. The total investment cost per output power of the Pareto solutions does not increase significantly when increasing exergy efficiency below 51%, indicating the solutions with an exergy efficiency of around 51% are promising for practical designs.
Li3K3Ce2(BH4)12 and Li3K3La2(BH4)12 are prepared by ball milling appropriate amounts of LiBH4, KBH4, and CeCl3 or LaCl3.
A novel supercritical compressed air energy storage (SC-CAES) system is proposed by our team to solve the problems of conventional CAES. The system eliminates the dependence on fossil fuel and large gas-storage cavern, as well as possesses the advantages of high efficiency by employing the special properties of supercritical air, which is significant for the development of electrical energy storage. The thermodynamic model of the SC-CAES system is built, and the thermodynamic characters are revealed. Through the exergy analysis of the system, the processes of the larger exergy destruction include compression, expansion, cold storage/heat exchange and throttle. Furthermore, sensitivity analysis shows that there is an optimal energy releasing pressure to make the system achieve the highest efficiency when energy storage pressure is constant. The efficiency of SC-CAES is expected to reach about 67.41% when energy storage pressure and energy releasing pressure are 120 bar and 95.01 bar, respectively. At the same time, the energy density is 18 times larger than that of conventional CAES. Sensitivity analysis also shows the change laws of system efficiency varying with other basic system parameters. The study provides support for the design and engineering of SC-CAES.
Anaerobic digestion of renewable feedstocks has been known as a prospective technology for the production of clean energy in the form of biogas. Biogas is a sustainable energy carrier which is mainly composed of methane (60%) and carbon dioxide (35–40%). Among the raw substances, organic matters obtained from farm animal waste are pivotal sources for biogas production. In recent years, the number of animal husbandry has drastically grown in Malaysia. Accordingly, a large amount of animal waste including manure, blood and rumen content are produced which provide a tremendous source of biogas generation. This paper presents biogas potential from the organic waste obtained from the farm animals and slaughterhouses in Malaysia. The findings of this study indicated that biogas potential of 4589.49 million m3 year−1 could be produced from animal waste in Malaysia in 2012 which could provide an electricity generation of 8.27×109 kWh year−1.
In the emerging front of research, much attention is focused on the usage of hydrogen as a promising alternative energy carrier that can potentially replace fossil fuels. Conversely, the realization of hydrogen as an energy carrier becomes impounded since the light weight and compact hydrogen storage materials are still prerequisites for hydrogen fuel cell technology. In the present study, the performance of nanoclay composites composed of acid treated halloysite clay nanotubes (A-HNTs) and hexagonal boron nitride nanoparticles (h-BN) are investigated towards hydrogen storage. where facile ultrasonic approach was adopted. The prepared A-HNT–h-BN nanoclay composites subjected to various characterization techniques such as X-ray Diffraction (XRD), micro–Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), UV–Visible Diffuse Reflectance Spectroscopy (DRS), Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Spectroscopy (EDX) and High Resolution Transmission Electron Microscopy (HRTEM) with Selected Area Transmission Electron Diffraction (SAED). The presence of h-BN nanoparticles at the surface of A-HNTs can be seen from HRTEM images and these findings are supported by XRD, FTIR and Raman results. Hydrogen adsorption studies are performed using Sieverts-like hydrogenation setup. A 2.88 wt% of hydrogen storage capacity and 100% desorption were achieved for the A-HNT–5wt% h-BN nanoclay composite at 50 °C. The adsorbed hydrogen possess the average binding energy of 0.33 eV, which lies in the recommended range (0.2–0.4 eV) for fuel cell applications. So it is expected that A-HNT–h-BN nanoclay composites will serve as a better hydrogen storage material for fuel cell applications in the near future.
Safety issues pertaining to Li-ion batteries justify intensive testing all along their value chain. However, progress in scientific knowledge regarding lithium based battery failure modes, as well as remarkable technologic breakthroughs in computing science, now allow for development and use of prediction tools to assist designers in developing safer batteries. Subsequently, this paper offers a review of significant modeling works performed in the area with a focus on the characterization of the thermal runaway hazard and their relating triggering events. Progress made in models aiming at integrating battery ageing effect and related physics is also discussed, as well as the strong interaction with modeling-focused use of testing, and the main achievements obtained towards marketing safer systems. Current limitations and new challenges or opportunities that are expected to shape future modeling activity are also put in perspective. According to market trends, it is anticipated that safety may still act as a restraint in the search for acceptable compromise with overall performance and cost of lithium-ion based and post lithium-ion rechargeable batteries of the future. In that context, high-throughput prediction tools capable of screening adequate new components properties allowing access to both functional and safety related aspects are highly desirable.
Stable charge-discharge cycling behavior for a lithium metal anode in a dimethylsulfoxide (DMSO)-based electrolyte is strongly desired of lithium-oxygen batteries, because the Li anode is rapidly exhausted as a result of side reactions during cycling in the DMSO solution. Herein, we report a novel electrolyte design for enhancing the cycling performance of Li anodes by using a highly concentrated DMSO-based electrolyte with a specific Li salt. Lithium nitrate (LiNO3), which forms an inorganic compound (Li2O) instead of a soluble product (Li2S) on a lithium surface, exhibits a >20% higher coulombic efficiency than lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, and lithium perchlorate, regardless of the loading current density. Moreover, the stable cycling of Li anodes in DMSO-based electrolytes depends critically on the salt concentration. The highly concentrated electrolyte 4.0 M LiNO3/DMSO displays enhanced and stable cycling performance comparable to that of carbonate-based electrolytes, which had not previously been achieved. We suppose this enhancement is due to the absence of free DMSO solvent in the electrolyte and the promotion of the desolvation of Li ions on the solid electrolyte interphase surface, both being consequences of the unique structure of the electrolyte.
The hydrogen storage performance of ball-milled MgH2 with 5 wt% ZrO2 + 5 wt% single-walled carbon nanotubes as additives was investigated. We found that the hydrogen sorption kinetics of magnesium is markedly improved by these co-additives. At a temperature of 423 K, the sample absorbs around 6.73 wt% H2 in the first 100 s. However, at a temperature of 298 K, the sample absorbs 1.06 wt% H2 in 100 s. Notably, the sample still absorbs 4.00 wt% H2 within 700 s under ambient temperature conditions (298 K).
The theoretical analysis of MgH2, ZrO2 and SWCNT alloy powers at different temperatures also have been studied. By theoretical analysis of the experimental data of the pyrolytic hydriding reaction and fitting them with the Johnson–Mehl–Avrami (JMA) equation, the kinetic equation and the corresponding kinetic parameters including the reaction order, the reaction rate constant, and the reaction activation energy have been obtained. Furthermore, the reason why the MgH2 and ZrO2 alloy powders can absorption at room temperature has been interpreted referring to the thermodynamic and kinetic factors.
A brief review of the different methods of hydrogen storage process for application in automobile manufacturing was presented and discussed. The hydrogen storage by adsorption on super activated carbon AX21 at various thermodynamic conditions was investigated. In order to describe the reality of the system, we planned a brief review, a discussion and modeling of the different EOS equations adapted to a hydrogen gas. Different characterization tools for obtaining the physical property of AX21 were used, among them SEM, BET and Helium displacement method at high temperature. The hydrogen storage capacity of AX21 at different temperature and pressure up to 70 MPa was investigated experimentally. In order to describe the experimental hydrogen gas excess adsorption results, the model of Chilev and a modified potential theory were selected. The comparison of the two models describing adsorption isotherms and a critical discussion of their accuracy was given. Based on the models results the absolute amount adsorbed was obtained. The difference between an absolute and an excess amount adsorbed at 77 K and 293 K was discussed. A comparison between the volumetric tank capacity obtained by pure compression and the adsorption process at both temperatures were studied. The method of hydrogen storage and optimal operating conditions were investigated.
Partial dehydrogenation (PDh) of fuels is a novel method to generate high purity hydrogen on-board, in order to directly feed a fuel-cell based power unit. In this work, the PDh of diesel and gasoline has been studied in order to investigate the possibility of applying such a system to vehicles. The studies have been performed with a Pt-Sn/γ-Al2O3 catalyst using a series of diesel and gasoline surrogates. The reactivity of the fuels has been studied, identifying different reaction mechanisms, in relation to the chemical composition and the process conditions. The PDh of a gasoline surrogate provides an average hydrogen production of 1800NLh-1kgcat-1 with a purity of over 99% vol. and an extrapolated catalyst lifetime of over 300h. With diesel, PDh gave an average hydrogen production of 3500NLh-1kgcat-1, a purity of over 99% vol. and a lifetime of only 29h. These preliminary results open up interesting perspectives for future applications of the partial dehydrogenation technology to feed on-board fuel-cells.
The density of states and the H absorption energy of AgxRh1-x alloys were theoretically investigated by the first-principles method. The electronic structure of the alloys near the Fermi edge was similar to that of Pd, which is known as hydrogen-storage metal, and this indicated the electronic state at the part plays important role to determine the H absorption property. The results showed that the H absorption into the AgxRh1-x alloys was thermodynamically stable and the trend of composition dependence agreed well with the experimental observation. Considering the atomic configuration of alloys, homogeneous structure is found to be a key in the emergence of H absorption nature in this alloy system.
Lithium-ion battery packs in hybrid and electric vehicles, as well as in other traction applications, are always equipped with a Battery Management System (BMS). The BMS consists of hardware and software for battery management including, among others, algorithms determining battery states. The accurate and reliable State of Health (SOH) estimation is a challenging issue and it is a core factor of a battery energy storage system.
In this paper, battery SOH monitoring methods are reviewed. To this end, different scientific and technical literature is studied and the respective approaches are classified in specific groups. The groups are organized in terms of the way the method is carried out: Experimental Techniques or Adaptive Models. Not only strengths and weaknesses for the use in online BMS applications are reviewed but also their accuracy and precision is studied. At the end of the document a potential, new and promising via in order to develop a methodology to estimate the SOH in real applications is detailed.