Energy Storage Methods Research Articles

Multi-stage planning method for independent energy storage based on dynamic updating of key transmission sections

A multi-stage planning method for independent energy storage (IES) based on dynamically updating key transmission sections (KTS) is proposed to address issues such as uneven power flow distribution and transmission congestion resulting from the high penetration of renewable energy sources and load growth. First, an IES planning model considering KTS constraints is established by searching and updating the KTS and associated constraints. This model takes into account IES investment and operation costs, maintenance costs, revenue from spot price differences, and penalties for system congestion. Then, a multi-stage planning method for energy storage is proposed based on the dynamic updating of KTS and the annual planning results. To verify the effectiveness and feasibility of the proposed method, a case study simulation is conducted using the improved IEEE 39-bus New England standard system. The results demonstrate the ability of the method to achieve multi-stage rolling optimization of IES, providing a reference for future efforts toward multi-stage planning of IES.

Optimal configuration method of photovoltaic energy storage in distribution network based on source-load coordination

Abstract To enhance the configurability of photovoltaic energy storage within distribution network systems and foster synchronized development of power sources and loads, a source-load coordinated approach for optimal photovoltaic energy storage configuration in distribution networks is introduced. An alternative multi-objective framework for optimal allocation of photovoltaic energy storage capacity in distribution networks is formulated, which is the optimal goal of maximum economic benefit of photovoltaic energy storage, the optimal goal of minimum network loss and the optimal goal of source-network load coordination. The constraints of the system’s power flow, energy storage charging and discharging capabilities, and an optimized allocation strategy for energy storage are established, and the objective function is solved with full consideration of source-network load coordination factors. The energy storage optimization is updated in the iterative process. Based on the update results, the process for optimal allocation of photovoltaic energy storage in the distribution network has been devised to attain the most efficient allocation. Experimental results indicate a minimal discrepancy between the actual and specified energy storage output, along with a reduced average output power resulting from the optimized photovoltaic energy storage configuration, which shows excellent performance in energy storage optimization configuration.

Energy storage comparison of chemical production decarbonization: Application of photovoltaic and solid oxide electrolysis cells

The fossil fuel driven chemical production leads to significant greenhouse emission, and the low-carbon emission technologies are necessary for carbon neutrality. The integration of solid oxide electrolysis cells (SOEC) and H2-O2 combustion can replace the fossil fuel and supply high-temperature heat for reactions. However, the energy demand keeps consistent but the renewable energy fluctuates with time. Therefore, energy storage is important for such a change. Clean fuel replacement and electrification are applied in a case study of ethylene plant, which requires 147 MW of clean fuel and 91.36 MW of grid power. Photovoltaic (PV) solar energy drives SOEC and liquefied H2, compressed H2, compressed air energy storage (CAES) are compared. A mixed integer nonlinear programming model is proposed to evaluate decarbonization effect and cost, which are balanced by multi-objective optimization. The results show that the liquefied H2 is superior to other choices because of the high efficiency. The hydrogen of 126.27 MW is the optimal point, which requires 415 MW SOEC and PV panels. Also, this study proposes that the power grid should communicate with energy consumers such as chemical plants to ensure the energy storage method, or supply renewable energy directly, which avoids energy loss and unreasonable energy transition.

Investigation methods for enhancing the energy consumption capacity of novel PV access distribution networks

Abstract This paper presents a method for reconstructing distribution networks using soft open point (SOP) and demand response (DR) energy storage, which can effectively solve the problems of voltage overruns, line overcurrent, and bidirectional flow currents caused by the photovoltaic (PV) getting into the distribution network. First, the model for the rebuilding of the distribution network is created by using the energy storage method of DR and SOP. Then, MISOCP, which stands for mixed-integer second-order cone programming, is the model that is used to change the distribution network reconfiguration, and the transformed model is solved by the MOSEK algorithm package in MATLAB. Finally, the strategy suggested in this research may successfully enhance the distribution grid’s consumption capacity after PV access, as shown by the verification in the IEEE33 node distribution grid system.

A high-performance aqueous Eu/Ce redox flow battery for large-scale energy storage application

We report the performance of an all-rare earth redox flow battery with Eu2+/Eu3+ as anolyte and Ce3+/Ce4+ as catholyte for the first time, which can be used for large-scale energy storage application. The cell reaction of Eu/Ce flow battery gives a standard voltage of 1.90 V, which is about 1.5 times that of the all-vanadium flow battery (1.26 V). Large standard voltage is conducive to the improvement of battery energy density and power density. The Eu2+/Eu3+electrode reaction in a NaCl solution on platinum electrode was investigated detailedly using cyclic voltammetry, linear sweep voltammetry, tafel plot and chronoamperometry. Unlike zinc-cerium flow battery, the active species of Eu/Ce flow battery are always present in the electrolyte, and no liquid-solid phase transition occurs. Thus, Eu/Ce flow battery is free of the problems associated with dendrite growth and theoretically have a longer cycle lifetime. The negative electrolyte is very sensitive to oxygen and can directly cause battery failure if exposed to air. The average energy efficiency of Eu/Ce flow battery exposed to air is only 22.0 %. However, the average energy efficiency of Eu/Ce flow battery stripped of oxygen reaches 82.7 % at 25 mA/cm2. Preliminary experimental studies have shown that Eu/Ce flow batteries are a promising method for large-scale energy storage.

Design and analysis of a concentrated solar power-based system with hydrogen production for a resilient community

This paper investigates how to improve the utilization of solar energy in concentrated solar power plants for multi-tasked operation, including hydrogen production. In this regard, an integrated energy system with multiple power generation stages is developed to utilize heat from concentrated solar collector with molten salt thermal energy storage system. The two-stage steam Rankine cycle and organic Rankine cycle are used as power generation cycles in order to utilize heat from the molten salt at different temperature levels, which improves source utilization for power generation. Continuous energy supply is considered a crucial challenge for renewables, which can be achieved by diversifying the source or adding energy storage. The current study uses two different energy storage methods to ensure the continuous energy supply to achieve self-sufficiency as well for the community. Hydrogen energy subsystem is the second energy storage within the integrated system, which is the secondary energy storage that is used if heat is not sufficient to drive the power generation cycles. In order to make decisions for a better source utilization, ensure continuous power supply, and facilitate the operations of the components and energy storage subsystems according to the loads and source availability, an operational decision-making strategy is developed and applied within the spreadsheet model. In order to test the proposed system and the developed algorithm, a time-dependent analysis is carried out where hourly community load and hourly source data are employed. The analyses are carried out using the first and second laws of thermodynamics, primarily through energy and exergy aspects. The power cycle can generate power from heat within the temperature range of 160°C and 500°C, in between 6.12% and 37.2% of heat to power energy conversion efficiency. The overall energy and exergy efficiencies of the integrated system are found to be 31.29% and19.71% by considering the average meteorological data.

Multi-Stage Coordinated Planning for Transmission and Energy Storage Considering Large-Scale Renewable Energy Integration

Due to the large-scale integration of renewable energy and the rapid growth of peak load demand, it is necessary to comprehensively consider the construction of various resources to increase the acceptance capacity of renewable energy and meet power balance conditions. However, traditional grid planning methods can only plan transmission lines, often resulting in low utilization rates of newly constructed lines. Additionally, static planning methods can only address single-target scenarios and cannot cope with dynamic growth in load and renewable energy. To address these issues, this paper proposes a multi-stage collaborative planning method for transmission networks and energy storage. This method considers the non-line substitution effect of energy storage resources and their characterization methods. It establishes the coupling relationship between resources across different planning stages to achieve coordinated multi-stage planning for transmission networks and energy storage. Based on the IEEE-24 node system and a case study in a northern province of China, the results show that the proposed method reduces investment costs by approximately 30% compared to static planning methods and by about 7.79% compared to conventional grid planning methods. Furthermore, this method can accommodate more renewable energy.

Thermodynamic and economic analysis of a new CCHP system with active solar energy storage and decoupling of power and cooling outputs

The combined cooling, heating and power system effectively improves the energy conversion efficiency and reduces the fossil fuel consumption, can also satisfy multiple energy needs. A new multi-generation system including solar energy storage, thermochemical hydrogen production, solid oxide fuel cell, organic Rankine cycle, and double effect absorption refrigeration/heat pump is proposed, which achieves the decoupling of the cooling/heating output and power output by active energy storage method and effectively enhances the system flexibility to match the user loads. Two improved operation strategies of the new system are proposed to meet the user loads, with fuel saving rate of 19.31 %. The levelized cost of product, static payback period, dynamic payback period of the system under grid-assisted strategy are 0.0443$/kWh, 5.13years, 5.72years, respectively. While under the strategy of extra methanol to electricity for cooling, they are 0.0617$/kWh, 8.17years, 10.09years, respectively. On a typical day in summer, the CO2 emission rates are 144.07 g/kWh under grid-assisted strategy and 81.74 g/kWh under the strategy of extra methanol to electricity for cooling. On the typical day during the transition season and winter, the CO2 emission rates are 15.76 g/kWh and 53.52 g/kWh, respectively. The results of both operation strategies indicate the new system is economically viable and environmentally friendly.

Sonochemical synthesized Gd4Al2O9 nanostructures modified with carbonous compounds for electrochemical hydrogen storage application

In recent times, there has been a significant focus on research into the creation of an environmentally sustainable and pollution-free hydrogen storage cell power system. Over the last ten years, a number of significant advancements in energy storage methods have been developed, impacting research, innovation, and the likely course for furthering our understanding of energy storage. We suggest a hydrogen energy storage device built using cutting-edge electrochemical techniques and electrode materials. As active materials, a range of nanocomposites based on gadolinium aluminate (Gd4Al2O9) and carbonous compounds were created. For the fabrication of Gd4Al2O9 nanostructures, ultrasonic radiation was used in the presence of Schiff-base ligands of N,N′-bis(salicylidene)ethylenediamine (H2Salen), N,N0-disalicylidene-1,4-di-aminobutane (H2Salbn) and N,N′-bis(salicylidene)-1,2-phenylenediamine (H2Salophen). Diverse carbon-based materials of g-C3N4, GO and CNT were utilized for designing nanocomposites. After 15 cycles, the hydrogen storage capacities of pure Gd4Al2O9 were found to be 121 mAhg−1. Then, in the fifteenth cycle, the nanocomposites' capacity rose to 278 mAhg−1 at a current of 1 mA for designed nanocomposite with GO. The CNT can increase the capacity to 302 mAhg−1 (11th cycle) but the fading capacity was occurred after 11th cycle to 112 (15th cycle). The g-C3N4 led to decrease in capacity due to blocking the pore and active sites of Gd4Al2O9 nanostructures.

Flexible Aqueous Cr-Ion Hybrid Supercapacitors with Remarkable Electrochemical Properties in all Climates.

The integration of hostless battery-like metal anodes for hybrid supercapacitors is a realistic design method for energy storage devices with promising future applications. With significant Cr element deposits on Earth, exceptionally high theoretical capacity (1546 mAh g-1), and accessible redox potential (-0.74 V vs. reversible hydrogen electrode) of Cr metals, the design of Cr anodes has rightly come into our focus. This work presents a breakthrough design of a flexible Cr-ion hybrid supercapacitor (CHSC) based on a porous graphitized carbon fabric (PGCF) substrate prepared by K2FeO4 activation. In the CHSC device, PGCF acts as both a current collector and cathode material due to its high specific surface area and superior conductivity. The use of a highly concentrated LiCl-CrCl3 electrolyte with high Cr plating/stripping efficiency and excellent antifreeze properties enables the entire PGCF-based CHSC to achieve well-balanced performance in terms of energy density (up to 1.47 mWh cm-2), power characteristics (reaching 9.95 mW cm-2) and durability (95.4 % capacity retention after 30,000 cycles), while realizing it to work well under harsh conditions of -40 °C. This work introduces a new concept for low-temperature energy storage technology and confirms the potential application of Cr anodes in hybrid supercapacitors.

Flexible Aqueous Cr‐Ion Hybrid Supercapacitors with Remarkable Electrochemical Properties in all Climates

AbstractThe integration of hostless battery‐like metal anodes for hybrid supercapacitors is a realistic design method for energy storage devices with promising future applications. With significant Cr element deposits on Earth, exceptionally high theoretical capacity (1546 mAh g−1), and accessible redox potential (−0.74 V vs. reversible hydrogen electrode) of Cr metals, the design of Cr anodes has rightly come into our focus. This work presents a breakthrough design of a flexible Cr‐ion hybrid supercapacitor (CHSC) based on a porous graphitized carbon fabric (PGCF) substrate prepared by K2FeO4 activation. In the CHSC device, PGCF acts as both a current collector and cathode material due to its high specific surface area and superior conductivity. The use of a highly concentrated LiCl−CrCl3 electrolyte with high Cr plating/stripping efficiency and excellent antifreeze properties enables the entire PGCF‐based CHSC to achieve well‐balanced performance in terms of energy density (up to 1.47 mWh cm−2), power characteristics (reaching 9.95 mW cm−2) and durability (95.4 % capacity retention after 30,000 cycles), while realizing it to work well under harsh conditions of −40 °C. This work introduces a new concept for low‐temperature energy storage technology and confirms the potential application of Cr anodes in hybrid supercapacitors.

Design of Underwater Compressed Air Flexible Airbag Energy Storage Device and Experimental Study of Physical Model in Pool

Renewable energy is a prominent area of research within the energy sector, and the storage of renewable energy represents an efficient method for its utilization. There are various energy storage methods available, among which compressed air energy storage stands out due to its large capacity and cost-effective working medium. While land-based compressed air energy storage power stations have been constructed worldwide, their efficiency remains low. Underwater compressed air energy storage has the potential to significantly enhance efficiency, although no such device currently exists. This paper presents the design of an UWCA-FABESD utilizing five flexible air bags for underwater gas storage and discharge. Additionally, it introduces the working principle of the adiabatic underwater compressed air energy storage system and device. Furthermore, a small-scale physical model with similar functionality was designed and manufactured to simulate the charging process of the air bag in onshore charging and discharging tests as well as posture adjustment and lifting arrangement tests, along with underwater charging and discharging tests. These experiments validated the related functions of the designed underwater compressed air flexible bag energy storage device while proposing methods for its improvement. This research provides a new approach to underwater compressed air energy storage.

A Review of Thermochemical Energy Storage Systems for District Heating in the UK

Thermochemical energy storage (TCES) presents a promising method for energy storage due to its high storage density and capacity for long-term storage. A combination of TCES and district heating networks exhibits an appealing alternative to natural gas boilers, particularly through the utilisation of industrial waste heat to achieve the UK government’s target of Net Zero by 2050. The most pivotal aspects of TCES design are the selected materials, reactor configuration, and heat transfer efficiency. Among the array of potential reactors, the fluidised bed emerges as a novel solution due to its ability to bypass traditional design limitations; the fluidised nature of these reactors provides high heat transfer coefficients, improved mixing and uniformity, and greater fluid-particle contact. This research endeavours to assess the enhancement of thermochemical fluidised bed systems through material characterisation and development techniques, alongside the optimisation of heat transfer. The analysis underscores the appeal of calcium and magnesium hydroxides for TCES, particularly when providing a buffer between medium-grade waste heat supply and district heat demand. Enhancement techniques such as doping and nanomaterial/composite coating are also explored, which are found to improve agglomeration, flowability, and operating conditions of the hydroxide systems. Furthermore, the optimisation of heat transfer prompted an evaluation of heat exchanger configurations and heat transfer fluids. Helical coil heat exchangers are predominantly favoured over alternative configurations, while various heat transfer fluids are considered advantageous depending on TCES material selection. In particular, water and synthetic liquids are compared according to their thermal efficiencies and performances at elevated operating temperatures.

How new nanomaterials can improve the performance of lithium batteries

Abstract In recent years, lithium batteries have become energy storage methods in many fields for their advantages of high energy density, and many fields such as civil electric vehicles, electronic products, and aerospace rely on lithium batteries. At present, the performance demand for lithium batteries in electric vehicles is increasing, and finding ways to improve the performance of lithium batteries has become a top priority. Since silicon has the highest theoretical specific capacity, carbon nanotube technology is relatively mature, and the research and development prospects of new negative electrode materials for nano-batteries are broad. This paper analyzes the different influences of nano-silicon-based materials, carbon nanotubes modified by new materials and new negative nano-lithium materials on lithium batteries from nanomaterials. And summarize their respective roles to help readers further understand the application of nanomaterials in lithium batteries. It is designed to help readers further understand the application of nanomaterials in lithium batteries.

Study of Electricity Generation From Solar Energy and Energy Storage Methods

Solar energy is the most abundant source of energy. Among all the non-conventional, renewable energy sources, solar power provides great potential for conversion into electrical power. It is well known that solar technologies convert solar energy into electrical power through photo voltaic (PV) panels or through mirrors that concentrate solar radiation. The present paper is the study of the way electric energy is generated from solar energy by using PV panels and explores, the possibility of storage of energy generated using pumped based and gravity storage system. The operation of this paper is based on storing water in a very large reservoir at some height from ground, by electricity generated from the solar panel. For this purpose, electrical energy generated by the solar energy is used in the pump for storing water in a large reservoir at some height (of about 20 meters) from ground, this reservoir can be used as a charge storage device to produce electricity for future use. Further the gravity battery is also used to store the excess energy produced by solar panel. The whole system can be used for continuous power supply without any interruption.

Unveiling the marine Sargassum horneri material for energy and active sensor devices: Towards multitasking approaches

The quest for a future with greater environmental sustainability has led to a rising focus on investigating innovative methods for energy production and storage. However, marine invasions have steadily increased over the past two centuries, necessitating innovative approaches for the remediation and preservation of oceanic environments. Especially, Sargassum horneri (S. horneri) is a brown algae that causes massive floating macroalgal blooms along the coasts of East Asia. Given these facts, this paper develops high-performance triboelectric nanogenerator (TENG), and electrode material for both supercapacitor and water-splitting devices based on S. horneri. The TENG device, constructed using S. horneri coastal bio-waste collected from Jeju Island, yields impressive results. The output current, voltage and power generated by the S. horneri-based triboelectric nanogenerator (SH-TENG) is around 47 µA, 775 V, and 2880 µW, respectively. The electrochemical analysis of carbon derived from S. horneri reveals an excellent electrode capacitance of 225 F/g at 2.5 mA. Constructing the symmetric supercapacitor device using S. horneri-derived carbon, which shows excellent energy and power densities around 14.85 Wh/kg and 972.22 W/kg, with remarkable cyclic stability of 81.3 % for 5000 GCD cycles at 7 mA. On the other hand, the developed S. horneri electrode demonstrated much-improved activity towards water splitting application, exhibiting overpotentials of 0.101 V and 0.198 V for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at an applied current density of 20 mA/cm2, respectively. The fabricated sample also demonstrated the lowest Tafel values towards HER (119 mv/dec) and for OER (109 mv/dec). Finally, the time series analysis (TSA) technique was employed for modeling and prediction of capacity retention of the SH//SH supercapacitor and electrochemical potential (E) of SH/NF║SH/NF cell. In both cases, the mean squared error between experimental and predicted data was very small, suggesting the TSA is a powerful statistical technique to model and predict the vial features of the electrochemical devices. Overall, these results suggest that S. horneri-derived carbon presents a viable alternative in the realm of energy storage and harvesting, promising sustainable technological advancements.

Experimental study of solid particles in thermal energy storage systems for shell and tube heat exchanger: Effect of particle size and flow direction

The solid particle thermal energy storage method offers cost-effective, simple, and high-temperature suitable solutions. It effectively resolves chemical compatibility and thermal stress issues in shell-and-tube heat exchangers. This work studies the quartz sands' particle sizes and flow direction's impact on heat exchanger performance. The results show that heat conduction and natural convection heat transfer mechanisms exist on the particle side. Flow direction minimally affects charge/discharge time and stored energy but significantly impacts delivered/recovered energy and exergy and energy and exergy efficiencies. Optimal performance is achieved when HTO enters from the top during charging and from the bottom during discharging, creating a transparent thermal gradient of “Top Temperature High, Bottom Temperature Low”. This distribution minimizes natural convection losses, resulting in a 15–17 % increase in energy efficiency and an 11–13 % increase in exergy efficiency compared to reverse flow. Smaller particles show slightly faster temperature rise due to lower energy storage density. Large and medium particles perform well, achieving energy efficiencies of 81.5 % and 81.0 % and exergy efficiencies of 62.1 % and 61.8 %, respectively. Small particles have an energy efficiency of 79.0 % and an exergy efficiency of 60.4 %, possibly due to higher porosity and increased heat losses.

Effect of Metal d Band Position on Anion Redox in Alkali-Rich Sulfides.

New energy storage methods are emerging to increase the energy density of state-of-the-art battery systems beyond conventional intercalation electrode materials. For instance, employing anion redox can yield higher capacities compared with transition metal redox alone. Anion redox in sulfides has been recognized since the early days of rechargeable battery research. Here, we study the effect of d-p overlap in controlling anion redox by shifting the metal d band position relative to the S p band. We aim to determine the effect of shifting the d band position on the electronic structure and, ultimately, on charge compensation. Two isostructural sulfides LiNaFeS2 and LiNaCoS2 are directly compared to the hypothesis that the Co material should yield more covalent metal-anion bonds. LiNaCoS2 exhibits a multielectron capacity of ≥1.7 electrons per formula unit, but despite the lowered Co d band, the voltage of anion redox is close to that of LiNaFeS2. Interestingly, the material suffers from rapid capacity fade. Through a combination of solid-state nuclear magnetic resonance spectroscopy, Co and S X-ray absorption spectroscopy, X-ray diffraction, and partial density of states calculations, we demonstrate that oxidation of S nonbonding p states to S2 2- occurs in early states of charge, which leads to an irreversible phase transition. We conclude that the lower energy of Co d bands increases their overlap with S p bands while maintaining S nonbonding p states at the same higher energy level, thus causing no alteration in the oxidation potential. Further, the higher crystal field stabilization energy for octahedral coordination over tetrahedral coordination is proposed to cause the irreversible phase transition in LiNaCoS2.

Rule-Based Operation Mode Control Strategy for the Energy Management of a Fuel Cell Electric Vehicle

Hydrogen, due to its high energy density, stands out as an energy storage method for the car industry in order to reduce the impact of the automotive sector on air pollution and global warming. The fuel cell electric vehicle (FCEV) emerges as a modification of the electric car by adding a proton exchange membrane fuel cell (PEMFC) to the battery pack and electric motor, that is capable of converting hydrogen into electric energy. In order to control the energy flow of so many elements, an optimal energy management system (EMS) is needed, where rule-based strategies represent the smallest computational burden and are the most widely used in the industry. In this work, a rule-based operation mode control strategy for the EMS of an FCEV validated by different driving cycles and several tests at the strategic points of the battery state of charge (SOC) is proposed. The results obtained in the new European driving cycle (NEDC) show the 12 kW battery variation of 2% and a hydrogen consumption of 1.2 kg/100 km compared to the variation of 1.42% and a consumption of 1.08 kg/100 km obtained in the worldwide harmonized light-duty test cycle (WLTC). Moreover, battery tests have demonstrated the optimal performance of the proposed EMS strategy.

Enhancing visible light absorption of form-stable CH3COONa·3H2O composite phase change material and its application in thermoelectric power generation

The utilization of Phase Change Material (PCM) for solar heat storage represents an effective solar energy storage method. Nevertheless, this promising technology encounters several obstacles, particularly PCM leakage and dissatisfied solar absorptance. This study focuses on the development of a photothermal conversion composite PCM tailored for solar energy storage and its subsequent integration into a thermoelectric power generation system. The composite PCM was synthesized using an evaporation-impregnation method, with melamine foam (MF) serving as the adsorbent material, graphene oxide (GO) as the light-absorbing component, and sodium acetate trihydrate (SAT) as the thermal storage medium. It is shown that the MF demonstrates an exceptional adsorption capacity for SAT, whose mass fraction exceeds 99 % in the final composite. The composite PCM exhibits a remarkable melting enthalpy of 251.5 J/g, comparable to that of pure SAT. The integration of GO into MF/SAT improves the solar absorptance of the composite, elevating it from 23.3 % to 81.5 %, thereby enhancing the photothermal conversion performance. To assess the practical solar energy storage potential of the prepared PCM, a thermoelectric power generation system was designed and underwent a continuous 22-hour performance test in a real outdoor enviornment. The results reveal that the system is able to maintain voltage generation for about 10 hours after the sun disappears. This proves the superior photothermal conversion and heat storage capabilities of the prepared materials. This research offers a viable approach for direct solar energy storage and conversion to electricity, advancing renewable energy technologies.