Design Of Energy Storage System Research Articles

Pack-level performance of electric vehicle batteries in second-life electricity grid energy services

Repurposed electric vehicle (EV) batteries can provide an affordable and sustainable alternative to conventional utility-scale battery energy storage systems. While EV battery packs are often disassembled into modules or cells and repackaged for second life, the required time and labour costs can be mitigated by directly repurposing full EV battery packs when their health allows. However, the diversity among EV battery pack designs introduces uncertainty regarding their relative performance in second-life applications. This study presents experimental data demonstrating the second-life performance of EV batteries from five different EV manufacturers, featuring four unique positive electrodes, three cell formats, and three thermal management designs. All five EV batteries are tested at the pack level in their original housings, providing thermal conditions distinct from module or cell testing. The batteries are tested under 4 h, 2 h, and 1 h deep-discharge constant-power duty cycles to emulate electricity grid energy services such as energy arbitrage or peak shaving. Novel methods are employed to measure, assess, and compare battery performance in this test regime. The results show significant performance differences among the five EV battery packs, particularly between older (2012–2015) and newer (2018–2019) designs due to evolutions in energy density and thermal management. The test results are analyzed and ranked, showing that among the five tested batteries, the 2019 Tesla Model 3 battery (tested with active-liquid cooling) will provide the best overall performance in most second-life energy storage applications, while the 2015 BMW i3 battery (tested with passive-air cooling) will provide the best profit margins in applications where energy losses must be minimized. The novel experimental dataset is used to derive a number of generalized conclusions and recommendations which can be used by researchers and industrial developers to inform the modelling and design of second-life energy storage systems.

Numerical and experimental studies of packed bed thermal energy storage system based on a novel transient energy model

AbstractPacked bed thermal energy storage (PBTES) is an essential means to solve the temporal difference and continuity between energy supply and utilization in the fields of concentrating solar power, compressed‐air energy storage, and waste heat recovery. In this paper, to solve the imperfection and inaccuracy of the current energy model, a precise transient two‐dimensional multiequation model is developed. The model comprehensively considers thermal dispersion, wall effects, thermophysical property changes, and other factors. Experiments are performed to compare and validate the simulation results, and the simulation error is −4.5% to 1.9%, achieving excellent simulation accuracy. Also, the wall effect on the PBTES is observed, and the gas‐solid temperature fields exhibit an evident nonuniform oscillation distribution in the radial direction. The effects of storage tank length, thermophysical properties, particle diameter, and gas‐solid initial temperature on the heat release rate are discussed in detail. Results indicated that decreasing the tank length, increasing the gas‐solid temperature difference, and particle materials with high thermal diffusivities can increase the heat release rate, and a clear linear change was found. Particularly because a larger range of particle diameter variation is considered, the heat release rate is shown to vary nonlinearly with particle diameter, and the selection of the optimal diameter must comprehensively consider the effects of the heat capacity and the heat transfer rate. This study provides a theoretical basis for the design of thermal energy storage systems.

Investigation of Impulse and Continuous Discharge Characteristics of Large-Capacity Lithium-Ion Batteries

Lithium-ion batteries are one of the most popular and efficient energy storage devices. In this paper, the characteristics of high-capacity lithium-iron-phosphate batteries during the impulse and long-term operation modes of batteries with different levels of the discharge current are considered. A modified DP-model is proposed. The novelty of the model is the possibility to calculate the activation polarization parameters for different discharge currents. The state of charge is estimated using a high-order polynomial. Based on the developed model, transient processes with rapid load changes and the dependence of the battery voltage on the state of charge were obtained. Here, the model is intended to be used for the design of energy storage systems. The results showed that the DP-model is reliable under the tested conditions and can be used for the considered application.

Safety investigation of hydrogen energy storage systems using quantitative risk assessment

Hydrogen energy storage systems are expected to play a key role in supporting the net zero energy transition. Although the storage and utilization of hydrogen poses critical risks, current hydrogen energy storage system designs are primarily driven by cost considerations to achieve economic benefits without safety considerations. This paper aims to study the safety of hydrogen storage systems by conducting a quantitative risk assessment to investigate the effect of hydrogen storage systems design parameters such as storage size, mass flow rate, storage pressure and storage temperature. To this end, the quantitative risk assessment procedure, which includes data collection and hazard identification, frequency analysis, consequence analysis and risk analysis, was carried out for the hydrogen storage system presented in a previous study [1]. In the consequence analysis, the Millers model and TNO multi-energy were used to model the jet fire and explosion hazards, respectively. The results show that the storage capacity and pressure have the greatest influence on the hydrogen storage system risk assessment. More significantly, the design parameters may affect the acceptance criteria based on the gaseous hydrogen standard. In certain cases of large storage volume or high storage pressure, risk mitigation measures must be implemented since the risk of the hydrogen storage system is unacceptable in accordance with ISO 19880-1. The study highlights the significance of risk analysis conduction and the importance of considering costs associated with risk mitigation in the design of hydrogen storage system.

Technical Energy Assessment and Sizing of a Second Life Battery Energy Storage System for a Residential Building Equipped with EV Charging Station

This study investigates the design and sizing of the second life battery energy storage system applied to a residential building with an EV charging station. Lithium-ion batteries have an approximate remaining capacity of 75–80% when disposed from Electric Vehicles (EV). Given the increasing demand of EVs, aligned with global net zero targets, and their associated environmental impacts, the service life of these batteries, could be prolonged with their adoption in less demanding second life applications. In this study, a technical assessment of an electric storage system based on second life batteries from electric vehicles (EVs) is conducted for a residential building in the UK, including an EV charging station. The technical and energy performance of the system is evaluated, considering different scenarios and assuming that the EV charging load demand is added to the off-grid photovoltaic (PV) system equipped with energy storage. Furthermore, the Nissan Leaf second life batteries are used as the energy storage system in this study. The proposed off-grid solar driven energy system is modelled and simulated using MATLAB Simulink. The system is simulated on a mid-winter day with minimum solar irradiance and maximum energy demand, as the worst case scenario. A switch for the PV system has been introduced to control the overcharging of the second life battery pack. The results demonstrate that adding the EV charging load to the off-grid system increased the instability of the system. This, however, could be rectified by connecting additional battery packs (with a capacity of 5.850 kWh for each pack) to the system, assuming that increasing the PV installation area is not possible due to physical limitations on site.

Neural Network Approaches for Computation of Soil Thermal Conductivity

The effective thermal conductivity (ETC) of soil is an essential parameter for the design and unhindered operation of underground energy transportation and storage systems. Various experimental, empirical, semi-empirical, mathematical, and numerical methods have been tried in the past, but lack either accuracy or are computationally cumbersome. The recent developments in computer science provided a new computational approach, the neural networks, which are easy to implement, faster, versatile, and reasonably accurate. In this study, we present three classes of neural networks based on different network constructions, learning and computational strategies to predict the ETC of the soil. A total of 384 data points are collected from literature, and the three networks, Artificial neural network (ANN), group method of data handling (GMDH) and gene expression programming (GEP), are constructed and trained. The best accuracy of each network is measured with the coefficient of determination (R2) and found to be 91.6, 83.2 and 80.5 for ANN, GMDH and GEP, respectively. Furthermore, two sands with 80% and 99% quartz content are measured, and the best performing network from each class of ANN, GMDH and GEP is independently validated. The GEP model provided the best estimate for 99% quartz sand and GMDH with 80%.

Hybrid energy storage system design: Outlier performance improvement of x-EV battery pack

With the technological advancement in electrical mobility the perception of the customer is also inclining towards the electric vehicles. But still come customer are doubtful about the EV performance as compared to conventional ICE vehicles. This anxiety is fair as battery which is the primary component of xEVs still needs to grow further and needs to catch up with the performance standards of an internal combustion engine. Batteries can perform well as compared to IC engines in a fixed SoC range only but beyond this range the performance of the battery decreases. The work presented in this article is the effort to make battery performance inch further towards the ICE vehicle. This article demonstrates energy management strategy of a multi-chemistry battery pack to improve the vehicle performance in outlier conditions of the operational energy band and match the performance with IC engine vehicles. To demonstrate this a multi chemistry hybrid energy storage system is proposed which combines two distinct battery chemistries LFP end NMC in a single battery pack. These two different battery packs will be utilized to meet the power target and the energy target. To utilize the advancement of HESS as compared to SESS the energy management strategies are proposed. The results shows that the proposed solution can overcome the current performance limitation of the battery pack in terms of consistent power delivery over the entire operating range of vehicle during discharging and regeneration. With the proposed performance enhancement, the user may not feel the drop in acceleration towards the end of discharge the proposed strategy will also enhance the range and cycle life of the vehicle and the battery respectively.

Study on Integration of Retired Lithium-Ion Battery With Photovoltaic for Net-Zero Electricity Residential Homes

Abstract The behavior of a retired lithium-ion battery (LIB) from its first-life in an electric aircraft (EA) to its second-life in a solar photovoltaic (PV) system for a net-zero electricity residential home is studied. The first part of this study presents the design and sizing of a battery energy storage system (BESS), made from retired LIBs, to store a portion of the PV generation for a typical home in Ohio. The home is connected to the grid, but the net electricity usage from the grid in one year is zero. The purpose of the BESS is to peak shaving, power arbitrage, reduce the home dependency on the grid, and increase the economic benefits. The sizing is determined based on the hourly data of the PV system generation, ambient temperature, irradiation, and home demand electricity. In the second part of this study, the retired LIB degradation rate and its remaining useful life in the BESS are estimated using an adopted empirical LIB model. The model includes the capacity-fade for both first-life and second-life of the LIB under various duty cycles. It is shown that the retired LIB from its first-life is still suitable to be used in the PV grid-tied battery (PVGB) system for another 10 years. The results of this study can potentially reduce the LIB cost for electric vehicles (EVs) and EAs because the retired LIBs from these applications still have value to serve for other applications such as PVGB systems for residential homes.

Design optimization of a district heating and cooling system with a borehole seasonal thermal energy storage

The optimal design of borehole thermal energy storage systems can ensure their techno-economical goals are met. Current design optimization methods either employ detailed modelling unsuitable for numerical optimization or use simplified models that do not consider operational conditions. This paper proposes an optimization-oriented model and a non-convex optimization formulation that, differently from other studies in the literature, can consider the influence of the seasonal storage size and temperature on its capacity, losses, heat transfer rate, and efficiency of connected heat pumps or chillers. This methodology was applied to a case study, considering two scenarios: storing only the rejected heat from cooling and integrating solar thermal generation. Results show that, with varying boundary conditions such as the electricity CO2 intensity profile, cooling demand, and price of carbon emissions, not only the optimal seasonal storage size changes but also its optimal operating conditions. The potential reduction of CO2 emissions was found, under standard boundary conditions, to be limited (up to 6.7%), but an increase in cooling demand and an enhancement of the CO2 intensity seasonal variation led to a reduction of 27.1%. Integration of solar generation further improved it to 43.7%, with a comparably small increase in annual cost, up to 6.1%.

Efficiency analysis and heating structure design of high power electromagnetic thermal energy storage system

Based on the principle of electromagnetic induction, this paper proposes a new sleeve structure of electromagnetic induction heating energy storage system, which converts the electrical energy that cannot be consumed by wind power, solar power and other power grids into heat energy. The electromagnetic induction heating model of the eddy current field is established by Ansoft/Maxwell, and the magnetic induction intensity, current penetration depth and current frequency are analyzed. The three-dimensional fluid temperature field and its corresponding temperature characteristics of the system are analyzed by Ansys/Fluent. The temperature field cloud diagram of the sleeve is analyzed. It is concluded that with the increase of air thickness, the loss of the internal iron pipe increases, and the loss of the middle iron pipe decreases. The characteristic curve of the resonant circuit of the electromagnetic induction heating power supply is simulated and analyzed to determine the optimal parameters of the resonant circuit of the induction heating. A 100 kW electromagnetic energy storage system is developed, and the effectiveness and practicability of the method are verified, which can be applied to high power thermal energy storage.

Data Analytics and Information Technologies for Smart Energy Storage Systems: A State-of-the-Art Review

• A review of the applications of smart tools/technologies in ESS is conducted. • The advantages/limitations of data analytics, IoT, BMS and BIM are investigated. • Estimation of load, prices, renewable inputs, state of the charge, and fault diagnosis are emphasized. • The emerging issues and directions for future research in smart ESS are investigated. This article provides a state-of-the-art review on emerging applications of smart tools such as data analytics and smart technologies such as internet-of-things in case of design, management and control of energy storage systems. In particular, we have established a classification of the types and targets of various predictive analytics for estimation of load, energy prices, renewable energy inputs, state of the charge, fault diagnosis, etc. In addition, the applications of information technologies, and in particular, use of cloud, internet-of-things, building management systems and building information modeling and their contributions to management of energy storage systems will be reviewed in details. The paper concludes by highlighting the emerging issues in smart energy storage systems and providing directions for future research.

Dynamic performance and control scheme of variable-speed compressed air energy storage

To satisfy the requirements of large-scale utilization of renewable energy, the compressed air energy storage systems should exhibit a wide operating range. However, the flexibility of compressed air energy storage systems is limited by the turbomachinery character. Given that variable-speed operation can significantly broaden the flexibility of turbomachinery, a double-fed-induction-machine-based variable-speed compressed air energy storage (VS-CAES) system was proposed and studied for the first time. A numerical model integrating thermal-mechanical-electrical subsystems of VS-CAES was built. The control scheme of the VS-CAES system for max efficiency point tracking was well built and studied. The steady thermodynamic performance and dynamic performance of the VS-CAES system were analyzed and compared with those of the fixed-speed compressed air energy storage (FS-CAES) system. The results show that the variable-speed operation broadens the operation range of the charging process by 49 % under different pressure, while the influence on the operation range of discharging process is negligible. The off-design exergy efficiency increases by 0–6 % with an average of 1.8 % in the charging process and 0–1 % with an average of 0.5 % in discharging process. Under a 10 % step change of power setpoint command, the dynamic power response of VS-CAES is 0.3 s for both charging mode and discharging mode. In a contrast, the dynamic power response of FS-CAES is 26.5 s and 20.5 s. The research results of this study provide important guidance for the design and operation of compressed air energy storage system.

Design and Evaluation of Hydrogen Energy Storage Systems Using Metal Oxides

Design and Evaluation of Hydrogen Energy Storage Systems Using Metal Oxides

Synergetic Effect of Polyaniline and Graphene in Their Composite Supercapacitor Electrodes: Impact of Components and Parameters of Chemical Oxidative Polymerization.

The current development of clean and high efficiency energy sources such as solar or wind energy sources has to be supported by the design and fabrication of energy storage systems. Electrochemical capacitors (or supercapacitors (SCs)) are promising devices for energy storage thanks to their highly efficient power management and possible small size. However, in comparison to commercial batteries, SCs do not have very high energy densities that significantly limit their applications. The value of energy density directly depends on the capacitance of full SCs and their cell voltage. Thus, an increase of SCs electrode specific capacitance together with the use of the wide potential window electrolyte can result in high performance SCs. Conductive polymer polyaniline (PANI) as well as carbonaceous materials graphene (G) or reduced graphene oxide (RGO) have been widely studied for usage in electrodes of SCs. Although pristine PANI electrodes have shown low cycling stability and graphene sheets can have low specific capacitance due to agglomeration during their preparation without a spacer, their synergetic effect can lead to high electrochemical properties of G/PANI composites. This review points out the best results for G/PANI composite in comparison to that of pristine PANI or graphene (or RGO). Various factors, such as the ratio between graphene and PANI, oxidants, time, and the temperature of chemical oxidative polymerization, which have been determined to influence the morphology, capacitance, cycling stability, etc. of the composite electrode materials measured in three-electrode system are discussed. Consequently, we provide an in-depth summary on diverse promising approaches of significant breakthroughs in recent years and provide strategies to choose suitable electrodes based on PANI and graphene.

Modular battery energy storage system design factors analysis to improve battery-pack reliability

Traditional battery energy storage systems (BESS) are based on the series/parallel connections of big amounts of cells. However, as the cell to cell imbalances tend to rise over time, the cycle life of the battery-pack is shorter than the life of individual cells. New design proposals focused on modular systems could help to overcome this problem, increasing the access to each cell measurements and management. During the design of a modular battery system many factors influence the lifespan calculation. This work is centred on carrying out a factor importance analysis to identify the most relevant variables and their interactions. The analysis models used to calculate the reliability of the batteries are the state of health (SoH) and the Multi-State System (MSS) analysis with the Universal Generating Function (UGF), while electronic devices reliability is approximated using constant failure rate achieved with FIDES guide. Thus, it is determined numerically that module redundancy, cell capacity, module voltage and their interactions are the most determinant design characteristics.

A study on Li‐ion battery and supercapacitor design for hybrid energy storage systems

AbstractThis paper discusses a generic design of lithium‐ion (Li‐ion) batteries and supercapacitors, which are important sources for energy storage systems (ESS). The main contribution of this study is to compare the available and experimental models for batteries and supercapacitors operating under continuous charge or discharge conditions. Even though the available models show similar behavior to the experimental ones in short‐term or pulsed discharge conditions, this situation may be different in continuous discharge conditions. For this purpose, the optimal electrical equivalent circuits of energy storage devices were constituted and modeled in the MATLAB/Simulink environment. Then, the electrical equivalent circuit parameters were approximately calculated with the help of dynamic equations. Finally, the model parameters were estimated using Nonlinear Least Squares Method (NLSM) and Trust Region Reflective Algorithm (TRRA). When the obtained results were evaluated together, it has been observed that the electrical equivalent circuit models (EECM) more accurately reveal the transient and steady states of energy storage devices compared to the available models, especially under continuous discharge conditions.

Experimental studies on thermophysical properties of protic ionic liquids for thermal energy storage systems

Energy storage chemicals play an important role in the design of thermal energy storage systems due to their thermal and chemical properties. In this regard, ionic liquids can be used as a potential for thermal energy storage owing to their remarkable thermophysical properties. At present, little research has been done in this field. In this project, protic ionic liquids 2-hydroxyethylammonium lactate [HEA]La, bis(2-hydroxyethylammonium) lactate [BHEA]La and tris(2-hydroxyethylammonium) lactate [THEA]La were synthesized. The synthesized ionic liquids have low toxicity, high thermal stability, easy and economical synthesis with suitable physical and chemical properties for thermal energy storage systems. In the following, thermophysical measurements such as thermal conductivity, heat capacity, surface tension, density, speed of sound, and electrochemical potential windows for the pure ionic liquids at different temperatures were performed to evaluate the efficiency of these systems as thermal energy storage. The differential scanning calorimetry analysis shows that the ionic liquid 2-hydroxyethylammonium lactate has a higher heat capacity at 1.800 J·g−1·K−1 at T = 298.15 K than the other two ionic liquids due to its small cation and structure. Heat capacity also increases with increasing temperature. The electrochemical potential window values for the ILs [HEA]La, [BHEA]La and [THEA]La were obtained at 2.5 V and 2.2 V, and 1.7 V, respectively. Efficient thermal energy storage systems have a sufficiently high heat capacity and thermal energy density with beneficial thermal conductivity. The ionic liquid 2-hydroxyethylammonium lactate with a maximum thermal conductivity of 0.255 W·m−1·K−1 compared to the other two ionic liquids is recommended as an appropriate candidate for thermal energy storage.

Optimal coordinated design of under-frequency load shedding and energy storage systems

Under-frequency load shedding (UFLS) is considered a fundamental protection tool against power imbalances in electrical grids, particularly in small island systems. However, load shedding entails a delicate compromise between guaranteeing the stability of the system and disconnecting the lowest amount of load to achieve it. Fast-responding converter-interfaced energy storage systems (ESSs) can help improve such a compromise. In this regard, this paper proposes a methodology for the coordinated design of under-frequency load shedding (UFLS) and fast-responding converter-interfaced energy storage systems (ESSs). UFLS parameters include thresholds for frequency and its rate-of-change, and time settings of each step. ESS control parameters comprise, among others, the emulated inertia and the droop. The proposed coordinated methodology is applied to a real Spanish island power system with a 4 MW/5.6 kWh ultracapacitor (UC). Results show that the proposed methodology is able to significantly reduce the total amount of load shed with respect to the currently implemented UFLS settings and UC control parameters.

Optimization and Control of Renewable Energy Integrated Cogeneration Plant Operation by Design of Suitable Energy Storage System

Cogeneration is preferred mostly in process industries where both thermal and electrical energies are required. Cogeneration plants are more efficient than utilizing the thermal and electrical energies independently. Present government policies in India made renewable energy generation mandatory in order to minimize fossil fuels consumption and to protect the environment. Hence, many cogeneration plants have been integrated with renewable energy generation. However, post-integration effects increase and introduce inefficiencies in the operation of cogeneration systems. In this paper, a case study of an identified typical cogeneration plant where renewable energy is integrated is considered. Post operational effects on the plant due to integration of renewable energy (solar) are studied and by practical experimentation through cost-benefit analysis the break-even point beyond which renewable energy generation introduces inefficiencies is estimated. Next, a systematic methodology is developed based on the heuristic forward-chaining approach technique to establish the breakeven point. An algorithm/flow chart is developed using an iterative method and executed through MATLAB using practical data from the industry. Suggestions for suitable energy storage devices to store renewable energy beyond the breakeven point, based on a techno-economic analysis of energy storage technologies, are made. Further, the battery energy storage system is designed and the capacity is estimated based on the practical solar irradiance data. A rule-based algorithm is developed to control the charge and discharge cycles of battery storage based on predefined conditions. The payback period is estimated based on the expected monetary benefits of proposed energy storage and the economy of the proposed system is ensured. The post-operational issues are resolved by introducing energy storage. The methodology presented in this paper can be a guiding tool for optimization of various renewable-energy-integrated cogeneration systems.

A Novel Stochastic Model for Hourly Electricity Load Profile Analysis of Rural Districts in Fujian, China

Renewable energy is important for achieving carbon neutralization. However, power generation from renewable energy sources can be uncertain and uncontrollable. Therefore, understanding the features of energy demand is pivotal for integrating renewable energy sources and storage systems within the entire energy network. Traditional load profiles are depicted by fixed typical load curves, which cannot support detailed dynamic simulations of annual hourly electricity consumption. Here, a novel stochastic model for hourly electricity load profile analysis is proposed. A clustering-based model of hourly load was constructed to depict load profiles of typical days, while a non-linear regression method determined the temperature-related factors within annual daily load consumptions, based on which a stochastic simulation model was established for hourly electricity load profiles. The model’s performance was tested with electricity data of rural districts in Fujian Province, China. The proposed model achieved a coefficient of variation of the mean absolute error of 15.7%, which was significantly lower than that of the traditional model. Further, a simplified case was employed to analyze the application of the proposed stochastic model in the design of energy storage systems. The proposed method enables the optimal design of integrated energy networks with renewable energy sources and energy storage systems.