Energy Storage Mode Research Articles

Demand-side shared energy storage pricing strategy based on stackelberg-Nash game

With the large-scale access of user-side energy storage devices, shared energy storage has emerged as a key mode of energy storage in distribution networks. This mode requires efficient management of energy storage devices that balances the interests of different entities such as power supply enterprises, shared energy storage operators, and prosumers. In this mode, the formulation of charging and discharging prices is crucial. This paper proposed a dual-layer pricing model for shared energy storage systems based on mixed-game theory and its solution method. First, this study developed an upper-level stackelberg game model between the power supply enterprise and the cooperative alliance. The power supply enterprise, acting as the leader, sought to minimize operational costs while negotiating transaction electricity prices with the cooperative alliance. Second, a cooperative game model was developed within the lower-level alliance. As followers, the cooperative alliance seeks to maximize the alliance’s overall benefits. Based on the upper-level transaction electricity price and Nash bargaining theory, the internal transaction electricity price within the alliance was determined through negotiation. Subsequently, charging and discharging strategies were formulated along with a profit distribution mechanism. Finally, case studies simulations were used to validate the feasibility and effectiveness of the proposed model.

Optimal configuration of shared energy storage system in microgrid cluster: Economic analysis and planning for hybrid self-built and leased modes

Applying shared energy storage within a microgrid cluster offers innovative insights for enhancing energy management efficiency. This investigation tackles the financial constraint investors face with a limited budget for shared energy storage configuration, conducting a thorough economic analysis of a hybrid model that integrates self-built and leased energy storage modes. It also underscores the significance of energy sharing among microgrids. Departing from conventional single-mode planning approaches, this study explores the synergistic benefits of the self-built and leased modes, focusing on their distinct advantages regarding upfront investment costs and lifecycle returns. Specifically, a step-cost decrement model is established, accurately depicting the economies of scale characteristics of the self-built energy storage mode. Based on this, a shared energy storage system model that integrates self-built and leased modes is proposed. Subsequently, a robust optimization model is formulated for configuring shared energy storage within a microgrid cluster, incorporating considerations of inter-microgrid energy sharing, seasonal variations in net load curves, and associated volatility. The column-and-constraint generation algorithm and strong duality theory are employed to solve the constructed model in two stages. Six distinct scenarios are designed to validate the effectiveness of the method and model proposed in this paper while also assessing the impact of investment budget and uncertain parameters on shared energy storage planning for a microgrid cluster. The results show that the proposed shared energy storage planning model significantly improves the economics of energy storage investment and system operation, even under budgetary constraints. It also reduces the dependency of a microgrid cluster on both shared energy storage and distribution grid when compared to models relying solely on self-built or leased mode. This study can guide investors and microgrid cluster operators in planning and implementing shared energy storage.

Research on the collaborative operation strategy of shared energy storage and virtual power plant based on double layer optimization

Large-scale access to distributed energy resources leads to new energy consumption problems and safe operation risks in the power system. Virtual power plants and shared energy storage are effective ways to promote the flexible consumption of distributed energy resources and improve the reliability and economy of power system operation. Based on the concept of sharing economy and considering the complementary characteristics of source and load resources between different virtual power plants, this paper focuses on the optimisation of shared energy storage and multi-virtual power plant operation. Firstly, distributed wind power, distributed photovoltaic and flexible load resources are aggregated into virtual power plants to analyze the cooperative operation mode of shared energy storage and multi-virtual power plant systems. Secondly, a two-layer decision model for shared energy storage configuration and multi-VPP system operation optimisation is constructed, with the upper model solving the optimal energy storage configuration scheme by maximising the revenue of the shared energy storage operator, and the lower model optimising the multi-VPP system operation strategy by minimising the total operation cost, the maximum amount of new energy consumed, and the minimum amount of carbon emission as the multi-objective optimisation strategy. Finally, a simulation analysis is carried out, and the results show that compared with the independent operation mode of each virtual power plant, the model proposed in this paper increases the annual profit of the shared energy storage operator by 7180¥, reduces the operating cost of the VPP system by 7.08 %, improves the rate of renewable energy consumption by 0.82 %, and reduces the annual carbon emission by 54.91 t, which realizes the mutual benefits of the virtual power plant and the shared energy storage.

Deconvoluting Effects of Lithium Morphology and SEI Stability through Interface Engineering

The widespread use of renewable energy resources and electrification is mandatory for transitioning into a fossil-fuel-free world. Currently, Li-ion battery (LIB) is the universal mode of electrochemical energy storage, but it is reaching the theoretical limit, creating the urgency of more efficient batteries for next-generation applications. Li-metal batteries (LMBs) are considered a key technology to overcome the current energy density limitations of LIBs. In the most energy-dense LMB configuration, the anode-free LMB, Li is directly plated on and stripped from the Cu current collector (CC), subjecting it to the most stringent cycling conditions and making performance regulation crucial. Therefore, engineering the Cu-electrolyte interface is both fundamentally and practically significant.The two most crucial performance modulators in LMBs are electrodeposited Li morphology and solid electrolyte interphase (SEI). The literature has shown that low surface area morphology and anion-derived SEIs are usually beneficial for improved performance. However, it is difficult to deconvolute the individual impact of low surface area morphology and anionic SEI species on performance as they coexist and are correlated. One reported approach to understand the decoupled effects of morphology and SEI is ultrafast electrodeposition of lithium outpacing SEI formation (>100 mA cm-2). Our work establishes a new approach applicable at regular plating and stripping conditions (1 mA cm-2) that uses interface engineering with atomic layer deposited (ALD) thin films to deconvolve Li morphology and SEI stability effects. First, we modify the Cu CC surface using two different thin films with distinct characteristics: resistive, acidic HfO2; and conductive, acidic ZnO.Leveraging ALD, we precisely control the thickness of the nanofilms and establish that increasing the film resistance results in improved performance due to resistance-derived Li morphology. Our approach of decoupling the impact of SEI species from morphology is to preform the SEI before cycling using a simple potential hold step for both these acidic films with opposite electrical properties at different thicknesses. We find that with increasing film thickness, generally, the preformed SEI has more anionic species due to the surface acidity of the thin films. Despite being anion-rich, the preformed SEI does not improve performance, which we attribute to its evolution into an organic-rich SEI during plating. Moreover, the impact of the preformed SEI is statistically insignificant during long-term cycling, whereas the role of resistance becomes more apparent. The effects are demonstrated through interface characterization and performance measurements in three different electrolytes, with at least a twofold increase in cycle life and improved capacity retention achieved in practical anode-free pouch cells. Our results thus indicate that morphological control is more effective for improved battery cyclability due to the inherent challenges with preformed SEI preservation, and as a result the resistance of the thin films is more important than surface acidity for CC modification.

Green Hydrogen Production Using Manganese – Vanadium Redox Flow Batteries

The redox flow batteries (RFBs) can be tuned to allow mining of surplus energy capacity and supplement green hydrogen economy as a one-stop station [1, 2].With this concept, an RFB can undergo two sequential discharging modes: i) electrochemical discharge of redox active species, and ii) chemical discharge to produce hydrogen gas, when surplus electricity is available, on the surface of electrocatalysts contained in additional external tanks (i.e., dual circuit RFB) [3, 4]. Herein, electrolytes with Mn3+/Mn2+ (RFB catholyte ~ 1.5 V vs. SHE) and V3+/V2+ (RFB anolyte ~ −0.26 V vs. SHE) redox species are flown to spatially separated external catalytic reactors to drive redox mediated water electrolysis. The fully charged V2+ redox mediator in the anolyte provides electrons to achieve hydrogen evolution reaction (HER) and thereby itself gets discharged to V3+ redox state before circulating back to flow battery tanks.Considering the additional layer of redox-mediated water electrolysis, it is imperative to identify benchmark cycling performance for a robust dual circuit RFB operation. In the first phase of our study, electrochemical behavior of Mn3+/Mn2+ redox couple in the favorable presence of V5+ as an additive was elucidated using ultramicroelectrode voltammograms. Despite significant performance enhancement, capacity fade during galvanostatic cycling could not be fully eliminated owing to Mn3+ disproportionation reaction and manganese crossover. Also, charge/discharge cycling profiles suggest that the inevitable Mn3+ disproportionation affects the true state-of-charge in electrolytes which in turn hinders their potential to generate hydrogen gas. Working towards hydrogen generation, our recent efforts have been to evaluate kinetics for hydrogen evolution reaction (HER) on different carbon substrate – electrocatalyst combinations in acidic V3+/V2+ environment. Overall, this study aims to provide a profound understanding of reliable operating conditions to establish a synergy between Mn3+ disproportionation during the conventional energy storage mode and the total volume of hydrogen gas produced during the secondary mode. References Reynard, D. and H. Girault, Combined hydrogen production and electricity storage using a vanadium-manganese redox dual-flow battery. Cell Reports Physical Science, 2021. 2(9): p. 100556. Amstutz, V., et al., Renewable hydrogen generation from a dual-circuit redox flow battery. Energy & Environmental Science, 2014. 7(7): p. 2350-2358. Peljo, P., et al., All-vanadium dual circuit redox flow battery for renewable hydrogen generation and desulfurisation. Green Chemistry, 2016. 18(6): p. 1785-1797. Piwek, J., et al., Vanadium-oxygen cell for positive electrolyte discharge in dual-circuit vanadium redox flow battery. Journal of Power Sources, 2019. 439: p. 227075.

Aluminum vacancy‐rich MOF‐derived carbon nanosheets for high‐capacity and long‐life aqueous aluminum‐ion battery

AbstractEco‐friendly and safe aqueous aluminum‐ion batteries as energy storage devices with low economic burden, high stability and fast ion transport have been lucubrated deeply in response to the call for sustainable development. However, the poor cycle performance caused by difficult (de‐)intercalation hinders the development prospect. In this work, the aluminum vacancy‐rich MOF‐derived carbon is constructed to achieve reversible aluminum storage during the charge‐discharge cycles. The MOF‐derived carbon with anti‐stacking waxberry‐like structure exhibits high capacity (282.1 mAh g−1 at 50 mA g−1) and long cycle performance (84.4% capacity retention rate at 1 A g−1 after 5000 cycles). Further investigations demonstrate that (de‐)intercalation occurs among the vacancies of carbon nanosheets in the form of hydrated aluminum ions. Meanwhile, the introduced nitrogen as energy storage sites contributes part of the capacity. The proposed aluminum vacancy engineering improves the current situation of the capacitive energy storage mode for 2D carbon materials, which may exploit an advanced theoretical model for the design of aqueous batteries.

Research on optimization of integrated energy system operation under shared energy storage mode

Research on optimization of integrated energy system operation under shared energy storage mode

Insights From the Radiation and Energy Storage Modes of Canonical Dipole Antennas

Insights From the Radiation and Energy Storage Modes of Canonical Dipole Antennas

Development pathway and influencing factors of hydrogen energy storage accommodating renewable energy growth

Hydrogen energy is considered an important energy storage mode with medium- and long-term cross-seasonal storage capabilities in scenarios with high penetration of renewable energy (RE). However, there is a lack of research regarding the appropriate scale of hydrogen energy storage (HES) considering different RE power generation scenarios. In response to this gap, the present study aims to establish a power system simulation model to analyze the development pathway of HES while accommodating RE growth with a minimum cost constraint for a power system operation. The impacts of carbon trading prices, advances in HES technology, and RE resource endowment on HES development are also investigated. The findings indicate that the total available solar energy resources in China are 46.94TW, and the total available wind energy resources are 9.52TW. When the share of RE generation reaches 44.33–54.78 % of total power generation, the utilization of HES for balancing power system is advantageous in reducing the overall system costs. Looking ahead to 2060, the year when China is projected to achieve its carbon-neutrality goal, RE is estimated to reach 63.12–91.1 % of total power generation. Consequently, the HES in each province is estimated to contribute to 3.58–18.02 % of total electricity consumption. Provinces with more abundant wind resources relative to solar resources are expected to have a 36.43 % higher demand for HES.

Toward local Madelung mechanics in spacetime

It has recently been shown that relativistic quantum theory leads to a local interpretation of quantum mechanics wherein the universal wavefunction in configuration space is entirely replaced with an ensemble of local fluid equations in spacetime. For want of a fully relativistic quantum fluid treatment, we develop a model using the nonrelativistic Madelung equations, and obtain conditions for them to be local in spacetime. Every particle in the Madelung fluid is equally real, and has a definite position, momentum, kinetic energy, and potential energy. These are obtained by defining quantum momentum and kinetic energy densities for the fluid and separating the momentum into average and symmetric parts, and kinetic energy into classical kinetic and quantum potential parts. The two types of momentum naturally give rise to a single classical kinetic energy density, which contains the expected kinetic energy, even for stationary states, and we define the reduced quantum potential as the remaining part of the quantum kinetic energy density. We treat the quantum potential as a novel mode of internal energy storage within the fluid particles, which explains most of the nonclassical behavior of the Madelung fluid. For example, we show that in tunneling phenomena, the quantum potential negates the barrier so that nothing prevents the fluid from flowing through. We show how energy flows and transforms in this model, and that enabling local conservation of energy requires defining a quantum potential energy current that flows through the fluid rather than only flowing with it. The nonrelativistic treatment generally contains singularities in the velocity field, which undermines the goal of local dynamics, but we expect a proper relativistic treatment will bound the fluid particle velocities at c.

Two-stage robust transaction optimization model and benefit allocation strategy for new energy power stations with shared energy storage considering green certificate and virtual energy storage mode

In the context of the large-scale participation of renewable energy in market trading, this paper designs a cooperation mode of new energy power stations (NEPSs) and shared energy storage (SES) to participate in the power-green certificate market, which divides SES into physical energy storage and virtual energy storage. Secondly, combining the advantages of scenario generation and robust optimization (RO), a two-stage RO model with improved uncertainty interval is proposed to determine the optimal trading strategy. Then, to better align the distribution results of cooperative benefits with the actual contributions of NEPSs and SES, an entropy weight modified Shapley value benefit allocation strategy is constructed. Finally, the new energy base in Qinghai Province, China is chosen for simulation. The results show: (1) Adding energy storage and using two-stage RO are able to effectively improve the ability of NEPSs to resist uncertainty, which increases the revenue of the alliance by 22.8%. (2) The application of SES has better economic benefits than each member equipped with energy storage separately. Compared with the latter, the deviation penalty cost of the former is reduced by 66.4%, and the revenue is increased by 3.4%. (3) The proposed entropy weight modified Shapley value method embodies the important auxiliary role of SES more obviously. Based on this method, the overall satisfaction of the alliance increases by 12.6%. Generally speaking, the optimization model and benefit allocation strategy proposed in this paper can provide guidance for NEPSs and SES participating in power trading, and promote the low-carbon transformation of the power sector.

Phase change storage solar heat pump hydronics based on cloud computing

In order to understand the solar heat pump heating system, a phase-change storage solar heat pump heating system based on cloud computing is proposed. This paper first introduces the solar heat pump as a phase change energy storage that can change four types of heat depending on the weather conditions and significantly reduce the energy consumption of the system. Second, through the special design of the energy storage capacitor, in addition adjusting the energy distribution of the solar heat pump system, it can also improve the reliability of supply and demand between the solar heat pump system and the building heating system, improve the level of solar energy consumption, but also improve the low temperature of the pump milk temperature, and improve the solar heat up quickly to achieve the goal of improving the overall performance of the heat pump. Finally, this paper takes an urban ?electric coal? house as a research object to investigate the hot air efficiency of solar heat pumps. This paper analyzes the daytime solar heat pump mode, the nighttime energy storage mode under extreme conditions, and the air source heat pump mode. And shows the research results that the solar heat pump has good heating efficiency and the highest solar COP. Will be heat pump is 5.28 solar energy average heat pump COP is 2.13. In very bad weather, solar heat pumps work better.

Ultrahigh Capacity from Complexation-Enabled Aluminum-Ion Batteries with C70 as the Cathode.

Restricted by the available energy storage modes, currently rechargeable aluminum-ion batteries (RABs) can only provide a very limited experimental capacity, regardless of the very high gravimetric capacity of Al (2980mAhg-1 ). Here, a novel complexation mechanism is reported for energy storage in RABs by utilizing 0D fullerene C70 as the cathode. This mechanism enables remarkable discharge voltage (≈1.65V) and especially a record-high reversible specific capacity (750mAhg-1 at 200mAg-1 ) of RABs. By means of in situ Raman monitoring, mass spectrometry, and density functional theory (DFT) calculations, it is found that this elevated capacity is attributed to the direct complexation of one C70 molecule with 23.5 (super)halogen moieties (superhalogen AlCl4 and/or halogen Cl) in average, forming (super)halogenated C70 ·(AlCl4 )m Cln-m complexes. Upon discharging, decomplexation of C70 ·(AlCl4 )m Cln-m releases AlCl4 - /Cl- ions while preserving the intact fullerene cage. This work provides a new route to realize high-capacity and long-life batteries following the complexation mechanism.

Control Strategy of Seamless Switching Between Grid-connected and Islanding Operation for Weak-connected Microgrid

A control strategy of seamless switching is proposed for the high-capacity microgrid, which is at the end of long-distance transmission. Firstly, the control modes of energy storage and diesel generator set under grid-connected conditions and islanding conditions are analyzed. Meanwhile, the seamless switching strategy for the microgrid, in which energy storage or diesel generator sets can be taken as the main power source adaptively, is proposed. During the switching from the grid-connected condition to the islanding condition, the connection line power is optimized according to the respective operational characteristics of the energy storage and diesel generator sets. And the interaction of the power step control with voltage blocking and the regulation characteristics of the line voltage regulator is utilized to effectively suppress the fluctuation of system voltage and frequency. Finally, the combination of auto-synchronization control and multiple synchronization control improves the success rate of switching from the islanding condition to the grid-connected condition. The on-site test results of an actual microgrid project verify the effectiveness of the proposed control strategy.

Optimized scheduling study of user side energy storage in cloud energy storage model.

With the new round of power system reform, energy storage, as a part of power system frequency regulation and peaking, is an indispensable part of the reform. Among them, user-side small energy storage devices have the advantages of small size, flexible use and convenient application, but present decentralized characteristics in space. Therefore, the optimal allocation of small energy storage resources and the reduction of operating costs are urgent problems to be solved. In this study, the author introduced the concept of cloud energy storage and proposed a system architecture and operational model based on the deployment characteristics of user-side energy storage devices. Additionally, a cluster scheduling matching strategy was designed for small energy storage devices in cloud energy storage mode, utilizing dynamic information of power demand, real-time quotations, and supply at the load side. Subsequently, numerical analysis was conducted to verify that the proposed operational mode and optimal scheduling scheme ensured the maximum absorption of renewable energy, improved the utilization rate of energy storage resources at the user side, and contributed to peak shaving and load leveling in the power grid. The model put forward in this study represents a valuable exploration for new scenarios in energy storage application.

Research Progress of Power Generation Technology Using Gravity Energy Storage in a Context of Carbon Neutrality

As the global economy improves by leaps and bounds, the skyrocketing energy consumption caused by the increase in population and rapidly developing in urbanization and industrialization has brought many serious challenges, such as global warming, environmental pollution, ecological damage, and resource scarcity. To solve these problems, countries are actively developing and utilizing energy resources to generate electricity, such as solar photovoltaics, wind, geothermal energy, ocean energy, and biomass. However, they cannot meet the growing electricity demand because of their intermittency and instability, and geographical constraints. Thus, the quest to discover innovative, sustainable, and effective modes of energy conversion and storage has emerged as one of the foremost critical concerns on the global stage. Compared to traditional electrochemical energy storage technologies, gravity storage offers higher safety, larger storage capacity, and lower environmental damage and significantly reduces the dependence on geographical conditions and water resources, with great potential for application.

Integration model and performance analysis of coupled thermal energy storage and ejector flexibility retrofit for 600 MW thermal power units

A flexible retrofitting method for thermal-energy-storage-coupled thermal power units is proposed. The exergy flow Sankey diagram and efficiency of the three charging methods was analyzed in detail, and comparative data were provided. The new thermal energy storage mode coupled with steam ejectors was the optimal solution, with a significantly higher round-trip efficiency than the published results. Further study of the mode revealed slight temperature variations in the molten salt did not affect system efficiency. As the extraction of reheated steam decreases and the extraction of main steam increases, the minimum generation capacity of the unit decreases continuously, reaching a minimum of 40 MW (6.67%). In contrast, the maximum output of the unit at 100% THA release can reach 682 MW, which caused the unit load to change from 26-100% to 6.67–113.67% before and after the retrofit. As the ejection coefficient increased, the round-trip efficiency increased significantly, corresponding to 73%, 77%, and 80% at the study points. The mathematical model based on principal component analysis can effectively characterize the relationship between the ejection coefficients, extraction of main steam, extraction of reheat steam, low valley peaking rate, peak modulation rate, and round-trip efficiency, providing a signal conversion basis for automatically controlling peaking commands during unit operation. Finally, the benefits before and after retrofitting were analyzed in terms of thermal plant operation, proving that the payback period of the system was 4.09 years. Peak tariff and auxiliary service revenue are the most critical parameters affecting the payback period, and a 10% reduction in the peak tariff corresponds to an increase in the payback period of one ∼ two years. The results of this study provide substantial theoretical and practical guidance for the flexible retrofitting of thermal power units.

Modelling and capacity allocation optimization of a combined pumped storage/wind/photovoltaic/hydrogen production system based on the consumption of surplus wind and photovoltaics and reduction of hydrogen production cost

To achieve “carbon neutrality”, clean energy such as wind and solar energy is being developed, but due to the random and intermittent characteristics of wind energy and photovoltaics, the instability of grid connections and the abandoning wind and photovoltaics need to be addressed urgently. This paper proposes a method to solve the problems of grid connection and abandonment in wind and photovoltaic generation systems, that is, to establish a combined pumped storage/wind/photovoltaic/hydrogen production system through the pumped storage and hydrogen production system. The system consists of a pumped storage/wind/photovoltaic complementary subsystem and a hydrogen production subsystem. First, different models in the system are modelled using Simulink and the characteristics of the models are analysed. Subsequently, the wind turbine model and the PV model are simulated to derive the wind-PV complementary characteristic curves, and it is found that the load demand cannot be met by relying on wind-PV complementary power generation alone. To achieve system stability and economy, pumped storage is configured to smooth the output of wind power and PV. After comprehensive consideration, the optimal pumped storage capacity is determined to be 1000 MW. Then, through the simulation of the pumped storage/wind/photovoltaic system, it is found that even though pumped storage can absorb the wind and photovoltaic outputs, there is still a surplus when the wind and photovoltaic outputs are in excess. Therefore, this surplus energy is used for hydrogen production and the configuration of the hydrogen production system is optimized using a particle swarm algorithm to minimize the cost per unit of hydrogen production. After particle swarm optimization, it was determined that the unit cost of hydrogen production was minimized to 3.54 CNY/Nm3 for the configuration of 55 electrolysis tanks of 4 MW and 219 lead-acid tanks of 1 MW/2 MWh. Meanwhile, the electrolysis tank simulation model and the lead-acid battery simulation model were used to obtain maps of their operating conditions, hydrogen production and hydrogen storage tank pressure. In view of the addition of an energy storage system to the wind and photovoltaic generation system, this paper comprehensively considers the two energy storage modes of pumped storage and hydrogen production, and proposes a corresponding capacity optimization configuration scheme, which has reference value for improving the consumption and stability of wind and photovoltaics and realizing the sustainable utilization of clean energy.

Experimental and numerical investigations on operation characteristics of seasonal borehole underground thermal energy storage

To investigate operation characteristics of seasonal borehole underground thermal energy storage (SBUTES) with different operational strategies, a model test platform with reduced size was established based on similarity principle. The test results show that the larger the start-stop time ratio, the smaller the average heat exchange rate per unit depth (HERPUD) of borehole, and the lower the energy storage efficiency, but the thermal energy storage and extraction capacity increase. For the time ratio of thermal energy storage to extraction (TROSE), the larger the TROSE, the larger the thermal imbalance rate of energy storage body, which will lead to the gradual increase or decrease of temperature of energy storage body and is not conducive to the operation of energy storage. Compared with the asynchronous mode of storage and extraction, the synchronous mode of storage and extraction can effectively reduce the average temperature of energy storage body and increase the heat exchange efficiency of boreholes during the thermal energy storage. The focused energy storage mode can improve the energy storage efficiency and soil temperature recovery rate, balance the thermal energy storage and extraction capacity, and thus the performance of SBUTES can be optimized. A 3-D CFD model of borehole energy storage was established to further find the influences of borehole layout forms, layout spacing and depths on characteristics of the SBUTES. It can be found that for the energy storage efficiency, the hexagonal layout is the highest, the rectangular layout is the lowest, and the circular layout is slightly higher than the square one. Under the same volume of boreholes group, increasing the spacing of inner boreholes can effectively alleviate thermal interference of inner boreholes during the thermal energy storage, and the heat exchange capacity undertaken by inner boreholes can be improved. But it is not conducive to thermal energy extraction. Although increasing borehole depth can increase thermal energy storage and extraction capacity and system operation efficiency, the increase degree is decreasing with the increase of borehole depth, and the greater the borehole depth, the smaller the influence of borehole depth on characteristics of SBUTES.

Research on nash game model for user side shared energy storage pricing

With the continuous promotion of the energy revolution, the market-oriented reform of electricity has become the first priority in the energy field, and small-scale energy storage devices on the user side have received more and more attention. However, the disorderly management mode of user-side energy storage not only causes a waste of resources, but also brings hidden dangers to the safe operation of the power grid, such as stability, scheduling and operation, power quality and other problems. To address this issue, this paper proposes a user-side shared energy storage pricing strategy based on Nash game. Firstly, an optimal operation model is established for each participant of energy storage operators, users and grid. Secondly, a cooperative game model is established based on Nash equilibrium theory for the participants under the constraints. Finally, the optimal pricing scheme is solved by simulation analysis of the model, and the feasibility of the proposed pricing mechanism is verified. The results show that the optimal pricing scheme can achieve the purpose of peak shaving and resource saving. At the same time, it can also realize the win–win situation for all parties.