Electric Battery Storage Research Articles

Algorithmic trading of real-time electricity with machine learning

Algorithmic trading is becoming the dominant approach in many electricity spot and futures markets. This paper focuses on the emerging interest in the less documented real-time imbalance markets, by developing reinforcement learning agents to find profit-making opportunities algorithmically. We develop a repeatable experimental setting to compare different market participants and explore the applications of Q-learning with neural networks for three types of market participants: a non-physical trader, a gas generator, and a battery electricity storage system. We backtest all three agents using British data across summer and winter months to compare their profits, risks and various experimental design considerations.

The Complex and Spatially Heterogeneous Nature of Degradation in Heavily Cycled Li-ion Cells

As service lifetimes of electric vehicle (EV) and grid storage batteries continually improve, it has become increasingly important to understand how cells perform after extensive cycling. The multifaceted nature of degradation in Li-ion cells can lead to complex behavior that may be difficult for battery management systems or operators to model. Accurate characterization of heavily cycled cells is critical for developing accurate models, especially for cycle-intensive applications like second-life grid storage or vehicle-to-grid charging. In this study, we use operando synchrotron x-ray diffraction (SR-XRD) to characterize a commercially manufactured polycrystalline NMC622 pouch cell that was cycled for more than 2.5 years. Using spatially resolved synchrotron XRD, the complex kinetics and spatially heterogeneous behavior of such cells are mapped and characterized under both near-equilibrium and non-equilibrium conditions. The resulting data is complex and multifaceted, requiring a different approach to analysis and modelling than what has been used in the literature. To show how material selection can impact the extent of degradation, we compare the results from polycrystalline NMC622 cells to an extensively cycled single-crystal NMC532 cell with over 20,000 cycles—equivalent to a total EV traveled distance of approximately 8 million km (5 million miles) over six years.

Battery electricity storage as both a complement and substitute for cross-border interconnection

Cross-border interconnectors play a critical role in fulfilling the growing demand for cleaner and more affordable electricity. They are integral to completing the single energy market in Europe, so the European Union has set ambitious targets for the coming decade. Many challenges affect and delay the development of transmission infrastructure, and the deployment of non-wires alternatives such as battery energy storage systems may threaten the financial viability of these investments. We evaluate the potential impact of storage deployment on the profitability of cross-border interconnectors using the European electricity market model “EuroMod”. We find that higher battery penetration than projected in ENTSOE's TYNDP in 2030 significantly reduces transmission surplus (by €267 m to €506 m) under different battery uptake scenarios. To maintain the expected total surplus as projected by TYNDP in 2030, the continent-wide transmission capacity must decrease by 4.1–7.0%, potentially superseding 19–33% of planned transmission capacity expansions to 2030. Although cross-border interconnectors are of strategic importance for energy security and flexibility, the results highlight the pressing need for regulators, policymakers, and private investors to account for the rapid uptake of storage and integrate both storage and interconnectors in system planning.

A Qualitative Study of Defects with Enhanced Transport Properties of Graphene Exfoliated from Gum Arabic by Rapid Sonication Method

Graphene‐like materials are utilized to make electrical devices, thermal sensors, biosensors, and energy storage batteries. Herein, an efficient and cost‐effective approach is demonstrated by modulating the sonication time duration for producing a few layers of graphene using the emulsification qualities of low‐cost and environmentally friendly gum Arabic. By implementing the modified approach, the production time for graphene synthesis is significantly reduced to a short duration as compared to preliminarily reported methodologies. XRD, field‐emission scanning electron microscopy, and Raman spectroscopic results of graphene samples are presented in order to study the nature of defects. The flakes are thin enough (20 nm) to seem semitransparent under the FESEM. From the combination of both I2D/IG and FWHM (2D), a predominant formation of 3–7 graphene layers is observed. It is identified that mainly foreign adatom defects are present, with a density of ≈1010 cm−2, which results in an increasing Hall carrier concentration (≈2 × 1023 m−3) and mobility (≈27 800 cm2 Vs−1). Furthermore, graphene has a higher electrical conductivity of ≈550 S cm−1, which is far better than previously reported. This research opens the way for the mass manufacturing of simple, green, and cost‐effective graphene with better quality and physical attributes.

Design of passive voltage balancer system for lead acid battery

The use of rechargeable batteries for electrical energy storage requires a voltage balancing system. The voltage balancing system requires monitoring in the use of rechargeable batteries so that they can be utilized properly and can improve the electrical energy storage system. In this research, a monitored lead acid battery voltage balancing system was designed so that the management of the battery voltage balance level and the storage of electrical energy in rechargeable batteries can be stored and used optimally. In this research a series of lead acid battery voltage detection and power dissipation circuits were designed. The power dissipation circuit uses the controlled shunt resistor method which is used when the voltage of the lead acid battery being charged exceeds the maximum voltage. This method is easy to implement and can display the value of the lead acid battery voltage and other parameters, so that it can be monitored by the user. The results obtained show that the average voltage error for batteries 1 and 2 is 0.09% and 0.3% respectively. The power dissipation circuit can dissipate lead acid battery power above the reference voltage VREF=±7 V, with a balanced voltage of 6.8 V at 140 minutes and 160 minutes.

Harvesting sustainability: vertical agricultural greenhouses powered by renewable energy technologies

ABSTRACT This study investigates the practicality of integrating renewable energy systems to meet the electricity needs of a self-contained hydroponic greenhouse that functions as an environmentally friendly facility with reliable air conditioning and electrical infrastructure. The first step is to assess the greenhouse’s annual electricity consumption and design a renewable energy system that can sustain this year-round. The results show that daily electricity consumption is between 0.75 and 2 kWh, with thermal air conditioning accounting for over 50% of the total consumption. To address this issue, a simulation model is developed to evaluate the performance of a hybrid photovoltaic/wind system connected to an electric storage battery and to optimize its integration into the greenhouse. This causes the battery’s voltage to generally increase during charging (to 350.5 V) and its state of charge to change non-linearly depending on the battery’s chemical makeup. An Energy Management System (EMS) is then developed for the Hybrid Renewable Energy System (HRES), which works in two modes to ensure the energy balance for uninterrupted power supply. An economic and environmental analysis of three scenarios is developed and concludes that the systems are effective and sustainable, with an estimated payback period of approximately 6 to 8 years.

Battery Electric Storage Systems: Advances, Challenges, and Market Trends

The increasing integration of renewable energy sources (RESs) and the growing demand for sustainable power solutions have necessitated the widespread deployment of energy storage systems. Among these systems, battery energy storage systems (BESSs) have emerged as a promising technology due to their flexibility, scalability, and cost-effectiveness. This paper aims to provide a comprehensive review of the diffusion and deployment of BESSs across various applications, analyzing their impact on grid stability, renewable energy integration, and the overall energy transition. The paper examines the key drivers and challenges associated with BESS adoption, as well as market trends influencing their proliferation. Through an analysis of empirical data, this study aims to shed light on the current state of BESS diffusion. Finally, this research contributes to the knowledge base surrounding battery storage technology and provides insights into its role in achieving a sustainable and reliable energy future.

Karakterisasi Spektroskopi Raman pada Purifikasi Mixed Hydroxide Precipitate dari Baterai Lithium Bekas

Electrical energy storage batteries are a form of this supporting technology. Lithium batteries are considered the most suitable battery technology for many types of electronic devices today. Waste of used batteries will also increase as LIB production increases. The recycling process is one way to dispose of used batteries because they contain high levels of heavy metals, which pose a significant risk. The most common treatment method for battery recycling is hydrometallurgy. The most important of the various hydrometallurgical steps is the leaching process. The mixed hydroxide precipitate (MHP) will be the product of the precipitation on the NMC metal. Na2SO4 is always an impurity present in MHP products. Therefore, the MHP still needs to be purified to achieve the highest possible purity so that it can be used as a cathode in battery manufacturing. Raman’s spectroscopic was used to analyze the characteristic of MHP purification with variation 30, 50, 70 and 90 oC.

Ultrasonic inspection of lithium-ion pouch cells subjected to localized thermal abuse

Safety concerns associated with thermal runaway (TR) in lithium-ion cells have limited their adoption in high-power applications such as battery electric vehicles or energy storage systems. In practice, cells are more likely to encounter localized heating than total volume heating, so detecting and preventing TR in this thermal loading environment remains critically important. In this work, we employ ultrasonic inspection (US) to probe NMC lithium-ion cells subjected to localized, thermal loading to illustrate the utility of ultrasonic methods for TR detection. The method employs US Gaussian pulses with two different center frequencies propagating along two different paths to gain additional knowledge of the internal state of a mechanically-confined, thermally-loaded pouch cell during localized heating between 200∘C and 450∘C in different iterations of the test. The time of flight shift (TOFS) and signal amplitude (SA) are used to indicate thermal loading. For a given frequency-path pair the TOFS and SA trends under different levels of thermal loading are consistent. Damage indicators are developed using the US characteristics to give a time-before-TR warning. We demonstrate that through the use of multiple frequency-path pairs and ultrasonic metrics, US measurements can detect an impending battery failure up to twenty-five minutes in advance of TR.

Potential of thermal, electricity and hydrogen storage systems for achieving sustainable buildings

The current global energy scarcity challenges and the urgent need to enhance building sustainability have emphasized the utilization of energy storage systems as a highly promising approach. This study assesses the energy, economic, and environmental (3E) potential of thermal, electricity and hydrogen storage systems in promoting the sustainability of buildings. To that end, several simulations have been performed for five energy storage systems: photovoltaic (PV) with batteries, PV with hydrogen storage, solar collectors with hot water storage, phase change materials (PCMs) and Trombe wall. The 3E performance of these systems is evaluated in three distinct climates, namely hot desert, Mediterranean and cold climates. The results show that employing batteries for electricity storage is more energy-efficient than using hydrogen in all considered climates. Moreover, combining solar thermal collectors and hot water storage yields excellent energy outcomes, especially in the hot desert climate, while integrating PCMs in exterior walls and roof exhibits higher energy savings (43.06–64.29%) than the Trombe wall technique (4.18–18.09%). Environmentally, all storage systems, except for the Trombe wall, are eco-friendly with carbon payback periods of around 2.21–2.51, 0.40–0.67, 0.55–0.64, and 2.80–4.04 years for PV with batteries, PV with hydrogen storage, solar collectors with hot water storage, and PCM, respectively. In economic terms, the best cost-effectiveness is achieved using PV with batteries, followed by solar collectors with hot water storage and PCMs, with discounted payback period/levelized cost of energy of about 4.98–5.48/0.035–0.039, 6.35–7.52/0.039–0.046 and 9.32–14.43 years/0.046–0.067 $/kWh, sequentially. In contrast, incorporating Trombe wall and PV with hydrogen storage reveals a low economic viability. Overall, these outcomes could help engineers and building owners get informed about the 3E benefits and disadvantages of each storage system, enabling them to select the most suitable ones.

An analysis of li-ion induced potential incidents in battery electrical energy storage system by use of computational fluid dynamics modeling and simulations: The Beijing April 2021 case study

To further grasp the failure process and explosion hazard of battery thermal runaway gas, numerical modeling and investigation were carried out based on a severe battery fire and explosion accident in a lithium-ion battery energy storage system (LIBESS) in China. The composition and transport law of gas caused by large-scale LIB failure were theoretically analyzed, and the explosion risk of thermal runaway gas mixture in complex space after accidental ignition were systematically discussed by the computational fluid dynamics (CFD) technology. After the investigation, the underground cable trench is the key channel that causes the thermal runaway gas of lithium iron phosphate batteries to be transported to the building 20 m away and induces the explosion. After about 8500 s of battery burning, the average concentration of the thermal runaway mixed gas diffused from the cable trench is 16.4%. The arrangement of obstacles in the accident building is the main factor determining the explosion overpressure of thermal runaway gas, and the overpressure generated at the end of the obstacle path exceeds 70 kPa. Multiple windows in the battery room play an effective explosion-venting effect, but increase the damage range of outdoor high-temperature flame. In addition, the System-Theoretical Accident Model and Processes (STAMP) was used to analyze the causes of the accident, and the safety constraints that should be imposed by the three control levels of the government, functional departments and energy storage power stations were introduced to prevent battery failure and fire accidents in the BESS. The research method and analysis results will provide important ideas and reference for the investigation of fire and explosion accidents in BESS.

An Empirical Approach to Optimize non-linear Problems of Domestic Energy Management Systems

Energy management system for domestic houses comprising photovoltaic energy production and battery electrical storage combined with time-variant electricity prices use to be controlled mean numerical optimization algorithms. The modelling of the system comprises the different involved devices, energy flows and their constrains, and an objective function, which parametrizes the object of the optimization (usually the minimization of the operative costs and/or the CO2 emissions). The solution of the optimization problem provides the optimal operation (charging/discharging) of the battery along the prediction horizon considered. Power inverter efficiencies are usually modelled by assuming that they have constant values, and hence, that charging and discharging energy-flows lie on the most probably operating region of the inverter. A more realistic modelling of the power inverter efficiencies should consider a non-linear parametrization of the efficiency curves. This consideration converts the optimization problem into a non-linear one. It this paper, we propose a method to solve non-linear optimization problems means iterations of linear optimization problems. At the first step, an optimization problem will be solved by using the values of the efficiencies of the battery inverter provided by the manufacturer for the values. The values of the solution of that problem will be the seed of an iterative process: with help of measured (dis)charging power curves and the optimized (dis)charging energy flows, new values of (dis)charging efficiencies will be determined, and a new optimization problem will be defined and solved. The process stops after a certain number of iterations, or once a convergence is achieved. The results of the experimentation show that the modified method improves the performance of the system by reducing the operative costs with respect to the original method. The results summarized in the table correspond to a whole year with a 15-minutes time resolution and a 24-hour prediction horizon. The second method has the same time-steps, and for each time step triggers an iterative process. Simulations were implemented in Matlab and run on a COREi7 processor (8th generation) platform with 16 GB RAM. A wide experimentation by selecting representative cases with shorter periods (one week) will be done. The main objective of these selected cases is to analyze the dependencies between both methods under different circumstances (seven consecutive days of the year with maximal and minimal solar radiation, seven consecutive days of the year with maximal and minimal standard deviation of the buy and sell prices).

Adaptive Control Strategy for Stationary Electric Battery Storage Systems with Reliable Peak Load Limitation at Maximum Self-Consumption of Locally Generated Energy

Nowadays, stationary battery storage systems are generally used to optimize the self-consumption of electricity generated locally or to limit the peak load of the local grid connection. Self-consumption optimization aims to achieve economic benefits by using more of the self-generated electricity within the local grid. Batteries used for the optimization of self-consumption tend to present low states of charge and, therefore, normally do not contribute to peak load limitation. Peak load limitation is used to minimize the grid connection power to enable more cost-efficient grid connections. However, this function can only be achieved year-round if there is sufficient surplus electricity production or if the battery can be charged from the grid. In the latter case, the batteries are often fully charged and do not significantly optimize the self-consumption. This study presents a new operating strategy that combines all the advantages of the previous operating modes with none of the disadvantages. This can be accomplished by combining the operation modes depending on the particular situation, together with a variable battery charging process. Furthermore, a simulation-based optimization procedure is introduced for the optimal configuration of the parameters. The potential of this operating strategy is demonstrated based on application examples. As a result, the operating strategy enables reliable peak load limitation all year round while simultaneously optimizing self-consumption. The operating strategy can easily be adapted to meet changing requirements such as the increasing charging power demands of electric vehicles. Thanks to a simple process based on common measured variables, the operating strategy can be integrated smoothly into practical applications.

Modeling of solar-assisted ground-coupled heat pumps with or without batteries in remote high north communities

Many subarctic communities rely entirely on fossil fuels for their energy needs. Solar-assisted ground-coupled heat pumps (SAGCHP) can be a solution to integrate renewable energy sources into their energy portfolios. However, it is currently unknown how such systems could operate in the context of the high North (cold ground, extreme mismatch between insolation and heating need, electricity from diesel). The objective of the paper is to develop a detailed model of a SAGCHP heating a house in Nunavik (Quebec, Canada) in order to gain a better understanding of its potential and limitations. The solar assistance is provided by PVs. Simulations with and without electric storage (batteries) were run. A complex tradeoff between four different modes of operation was obtained depending on the conditions of the system at each time step. For the test case, results show that the ground experiences a weak long-term thermal depletion partly compensated solar energy, but that a significant portion of the PV power production is preferably used by the compressor or stored in batteries rather than stored in the ground as heat. Over ten years, the SAGCHP system reduced fuel consumption respectively by 38.2% (without a battery) and 59.1% (with a battery).

Experimental investigation and comparative analysis of immersion cooling of lithium-ion batteries using mineral and therminol oil

Renewable energy can potentially mitigate the adverse effects of energy and environmental crises. The Lithium-ion battery, a storage system investigated in the present study, has a potential to increase the penetration of renewable energy technologies, due to its high mass and volumetric energy density. However, thermal management strategies are necessary for lithium-ion battery electrical storage to grow technologically and gain widespread acceptability. In the present work, a comparative study of the different cooling methods, namely, forced air cooling (FAC), direct liquid contact cooling (i.e., Mineral oil cooling (MOC), and therminol oil cooling (TOC)) with low-cost coolants have been carried out on 20 cells of 10Ah lithium-ion battery-stack at a discharge rate of 1C, 1.5C, 2C, 2.5C, and 3C. It is found that the maximum temperature of the battery module is reduced by 43.83%, 49.17%, and 51.54% for forced air cooling, therminol oil cooling, and mineral oil cooling respectively, at 3C discharge rate, compared to the natural air-cooling method.Under the experimental conditions studied, the maximum temperature of the battery pack is found to be within the desired value during forced convection cooling only up to 1.5C discharge rate, while the immersion cooling performed satisfactorily up to 2C discharge rate. This study demonstrates direct liquid contact cooling with low-cost dielectric fluids as a safe and efficient thermal management technology for high-energy density and high-current lithium-ion battery applications.

Realizing Renewable Energy Storage Potential in Municipalities: Identifying the Factors that Matter

Abstract The share of renewable energy in heat and power generation is expected to increase significantly and reach record levels in the coming decades. As a result, emerging energy storage technologies will be key elements in balancing the energy system. To compensate the variability and non-controllability of seasonally generated renewable energy (RES) (daily fluctuations in solar radiation intensity, wind speed, etc.) development of sufficient energy storage infrastructure in the regions will play a major role in transforming RES supply potential into reality. However, local public authorities that are responsible for creating an enabling policy environment for RES infrastructure development in regions encounter numerous challenges and uncertainties in deploying sufficient energy accumulation that often remain unanswered due to a lack of knowledge and on-site capacity, which in turn significantly hinders the regional path to climate neutrality. In this study, the PESLTE analytical framework and composite index methodology is applied to examine the multidimensional factors that influence the deployment of renewable energy storage technologies in municipalities: political, economic, social, legal, technological, and environmental. Developed model is approbated in a case study in a Latvian municipality where four different alternative energy storage technologies are compared: batteries for electricity storage, thermal energy storage, energy storage in a form of hydrogen, and energy storage in a form of biomethane.

An Empirical Approach to Optimize Nonlinear Problems of Domestic Energy Management Systems

Abstract Numerical optimization methods are used to reduce the operative costs and emissions of domestic houses comprising photovoltaic energy production and battery electrical storage combined with time-variant electricity prices. The modelling of the system comprises the different involved devices, energy flows and their constraints, and an objective function, which parametrizes the object of the optimization. The solution of the optimization problem defines the most adequate charging and discharging strategy of the battery into the future (prediction horizon). Power inverter efficiencies are usually modelled by assuming that they have constant values, and hence, that charging and discharging energy-flows lie on the most probably operating region of the inverter. A more realistic modelling of the power inverter efficiencies should consider a nonlinear parametrization of the efficiency curves. This consideration converts the optimization problem into a nonlinear one. It this paper, we modify a method to solve nonlinear optimization problems means iterations of linear optimization problems. The first iteration uses as seed values the solution of an optimization problem, which considers constant efficiencies of the battery inverter provided by the manufacturer of the battery. With the values of the solution of the optimization problem and with help of measured (dis)charging power curves and the optimized (dis)charging, new values of the efficiencies of the inverter of the battery will be determined, and the optimization problem will be with these values again computed. If a certain number of iterations is achieved or the values of the efficiencies converge, then the process stops.

CAMBIOS EN LA TRANSMITENCIA DEL ELECTROLITO A 254nm SEGÚN EL ESTADO DE SALUD DE LAS BATERÍAS DE PLOMO

The estimation of the state of health (SOH) of lead-acid batteries for electrical energy storage is an important factor when planning their replacement and energy management. There are many methods to calculate this parameter. The novelty of this work is that it employs an optical method that produces compelling results showing the variation of the UVC transmittance of the electrolyte when the battery has different SOH levels, which is a novel alternative to the existing one of ampere counting, which is also experimented within this work.

Aggregation model of various demand-side energy resources in the day-ahead electricity market and imbalance pricing system

We propose a tool for aggregating a large number of buildings’ electricity demand and photovoltaic (PV) generation, controllable heat pump water heaters (HPWH) and electric vehicles (EV) to minimize the procurement cost in a market transaction consisting of a day-ahead market and an imbalance pricing system. The novelty of this research is that the aggregator's strategy can be modeled including various uncertainties, and the value of multiple demand-side resources (DSRs) can be quantified within realistic market rules. The model shows that the ability to control the imbalance through real-time control of DSRs has significant economic benefits. In the control of HPWH hot water storage operation, the procurement cost can be reduced by 13% compared to nighttime operation when the same number of units are installed as the aggregate target rooftop PV and residential demand. The electric vehicle storage battery charge/discharge control can reduce the total cost by 38% compared to nighttime charging under the same conditions. The impact of the PV-prediction error on the procurement cost was found to be generally larger than those of other parameters, and the market-price-prediction error was found to be considerably large during EV charging and discharging optimization. Furthermore, the simulation confirms that the value of control saturates as the proportion of controllable DSRs increases compared to uncontrollable demand and generation.

Key Challenges for Grid‐Scale Lithium‐Ion Battery Energy Storage

AbstractA rapid transition in the energy infrastructure is crucial when irreversible damages are happening quickly in the next decade due to global climate change. It is believed that a practical strategy for decarbonization would be 8 h of lithium‐ion battery (LIB) electrical energy storage paired with wind/solar energy generation, and using existing fossil fuels facilities as backup. To reach the hundred terawatt‐hour scale LIB storage, it is argued that the key challenges are fire safety and recycling, instead of capital cost, battery cycle life, or mining/manufacturing challenges. A short overview of the ongoing innovations in these two directions is provided.