Tuning Energy Storage Characteristics of BaTiO3-based Ceramics Through Zr-substitution

Simultaneous enhancement of polarization and breakdown strength in lead-free BaTiO3-based ceramics

As a major regulating power source for power systems, pumped storage plays an important role in peak regulation, energy storage and promotion of new energy consumption, etc. It is important to comprehensively evaluate the service grid capacity of pumped storage power plant to better play its role. Based on this, this paper established an evaluation index system for pumped storage power plant with respect to the characteristics of peak regulation and energy storage and their contribution to achieve carbon peak and neutrality goals. A comprehensive evaluation method for pumped storage power plant serving the grid that considers the characteristics of energy storage is proposed, and finally validated by examples.

The characteristics of energy storage and dissipation in TiNi shape memory alloys were investigated experimentally based on the superelastic properties under various thermomechanical loading conditions. The influence of strain rate, cyclic loading and temperature-controlled condition on the characteristics of energy storage and dissipation of the material was investigated. Temperature on the surface of the material was observed and the influence of variation in temperature on the characteristics was clarified. The results obtained can be summarized as follows. (1) In the case of low strain rate, the stress plateaus appear on the stress-strain curves due to the martensitic transformation and the reverse transformation during loading and unloading. In the case of high strain rate, the slopes of the stress–strain curves are steep in the phase-transformation regions during loading and unloading. The recoverable strain energy per unit volume increases in proportion to temperature, but the dissipated work per unit volume depends slightly on temperature. In the case of low strain rate, the recoverable strain energy and dissipated work do not depend on both strain rate and the temperature-controlledcondition. (2) In the case of high strain rate, while the recoverable strain energy density decreases and dissipated work density increases in proportion to strain rate under the temperature-controlled condition, the recoverable strain energy density increases and dissipated work density decreases under the temperature-uncontrolled condition. In the case of the temperature-uncontrolled condition, temperature varies significantly due to the martensitic transformation and therefore thecharacteristics of energy storage and dissipation differ from these under the temperature-controlled condition. (3) In thecase of cyclic loading, both the recoverable strain energy and dissipated work decrease in the early 20 cycles, but change slightly thereafter. (4) The influence of strain rate, cyclic loading and the environment on the characteristics of energy storage and dissipation is important to be considered in the design of shape memory alloy elements.

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

In the context of power systems with a high proportion of renewable energy, energy storage plays a significant role in facilitating the consumption of renewable energy and ensuring the operational safety of power systems. However, the current power spot market's predominant power bidding model does not fully consider the physical and cost-operational characteristics of energy storage, which is not conducive to further incentivizing investment and construction of energy storage, and may indirectly affect the flexibility of energy storage in peak shaving and valley filling. This paper summarizes the key issues that need to be addressed for energy storage to participate in the spot market from two aspects: the power bidding model does not meet the requirements of the physical and cost-operational characteristics of energy storage, and the real-time market under this model cannot achieve optimal allocation of energy storage. Considering the energy constraints and cost characteristics of energy storage, a charge and discharge bidding model is proposed, which is based on the stored energy value of energy storage and is in line with the physical and cost-operational characteristics and real-time optimization needs of energy storage. Subsequently, a market clearing model for energy storage participation in the spot market under the state of energy bidding method is constructed, and based on the IEEE 39-bus test case, a comparative analysis of the nodal electricity prices, energy storage revenue, and total system costs under the proposed market participation model and the traditional power bidding model is conducted. Simulation results show that the proposed energy storage participation model in the spot market can better utilize the value of energy storage in peak shaving and valley filling compared to the conventional power bidding model, reducing the extreme electricity prices by up to 10%, increasing single cycle revenue of energy storage by 46%, and reducing the total operating costs of the system in scenarios with significant deviations in system load in the day-ahead and real-time markets.

Energy is the driving force for industrial development and social progress. This paper intends to measure the impact of the comprehensive demand response model with electric energy substitution proposed here on user satisfaction. From the perspective of load-side energy consumption curve changes, this paper adopts the energy consumption satisfaction index of three energy forms of electric and thermal to measure the performance of comprehensive demand response considering electric energy substitution. The characteristics of energy storage are analyzed. Transferable loads, interruptible loads and electric vehicles are incorporated into the integrated energy storage system as controllable load virtual energy storage, and three different integrated energy microgrid energy storage scenarios are established. The simulation results show that: (1) Compared with scenario 1, the energy storage of electricity, thermal and gas in the integrated energy microgrid system of scenario 2 is optimized. Compared with scenario 1, the energy storage of each time period in 0–24 h has a certain growth, and the increase between 02:00-08:00 is larger. Compared with scenario 2, in scenario 3, during the valley period, the user consumption is greatly reduced, the effect of energy storage is significantly improved, and the optimization effect of integrated energy storage characteristics is obvious. (2) The participation of controllable load and electric vehicle in energy storage will bring about 4% increase in energy storage capacity, but after considering the uncertainty of controllable load, it will bring a 6%-8% increase to the system, and the energy storage fluctuation of integrated energy microgrid energy storage is gentler. This paper provides a reference for the research on energy storage characteristics of uncertain integrated energy systems.

Charging and discharging characteristics of absorption energy storage integrated with a solar driven double-effect absorption chiller for air conditioning applications

To study the energy storage and dissipation characteristics of deep rock under two-dimensional compression with constant confining pressure, the single cyclic loading-unloading two-dimensional compression tests were performed on granite specimens with two height-to-width (H/W) ratios under five confining pressures. Three energy density parameters (input energy density, elastic energy density and dissipated energy density) in the axial and lateral directions of granite specimens under different confining pressures were calculated using the area integral method. The experimental results show that, for the specimens with a specific H/W ratio, these three energy density parameters in the axial and lateral directions increase nonlinearly with the confining pressure as quadratic polynomial functions. Under constant confining pressure compression, the linear energy storage law of granite specimens in the axial and lateral directions was founded. Using the linear energy storage law in different directions, the elastic energy density in various directions (axial elastic energy density, lateral elastic energy density and total elastic energy density) of granite under any specific confining pressures can be calculated. When the H/W ratio varies from 1:1 to 2:1, the lateral compression energy storage coefficient increases and the corresponding axial compression energy storage coefficient decreases, while the total compression energy storage coefficient is almost independent of the H/W ratio.

To promote the efficient use of energy storage and renewable energy consumption in the integrated energy system (IES), an economic dispatch strategy for the concentrating solar power (CSP)-IES with generalized energy storage and a conditional value-at-risk (CVaR) model is proposed. First, considering the characteristics of energy storage and distributed power supply timing, a CSP-IES configuration is established by using a CSP plant to achieve thermal decoupling of the combined heat and power unit and by defining the thermal storage system of the CSP plant and the battery as the actual energy storage. Second, the fuzzy response of the logistic function is used to optimize the time-of-use tariff to guide load shifting, and the load shifting is defined as virtual energy storage. Third, the CSP-IES economic dispatch model is established to consider the carbon emission allowance model. Finally, considering the system uncertainty, a fuzzy chance constraint is used to relax the system power balance constraint, and then the trapezoidal fuzzy number is transformed into a deterministic equivalence class, and the CVaR model is used as a risk assessment index to quantify the risk cost of the system due to uncertainty. The CSP-IES economic dispatch model with CVaR is constructed. The feasibility and effectiveness of the proposed optimization model are verified by comparing various scenarios.

Transient characteristics of thermal energy storage in an enclosure packed with MEPCM particles

Effects of pre-existing single crack angle on mechanical behaviors and energy storage characteristics of red sandstone under uniaxial compression

Mechanical properties of prosthetic feet can significantly influence amputee gait, but how they vary with respect to limb loading and orientation is infrequently reported. The objective of this study is to measure stiffness and energy storage characteristics of prosthetic feet across limb loading and a range of orientations experienced in typical gait. This study included mechanical testing. Force-displacement data were collected at combinations of 15 sagittal and 5 coronal orientations and used to calculate stiffness and energy storage across prosthetic feet, stiffness categories, and heel wedge conditions. Stiffness and energy storage were highly non-linear in both the sagittal and coronal planes. Across all prosthetic feet, stiffness decreased with greater heel, forefoot, medial, and lateral orientations, while energy storage increased with forefoot, medial, and lateral loading orientations. Stiffness category was proportional to stiffness and inversely proportional to energy storage. Heel wedge effects were prosthetic foot dependent. Orientation, manufacturer, stiffness category, and heel wedge inclusion greatly influenced stiffness and energy storage characteristics. These results and an available graphical user interface tool may help improve clinical prescriptions by providing prosthetists with quantitative measures to compare prosthetic feet.

Energy storage and hydrophobicity characteristics of cement-based materials containing paraffin-pumice at low air pressure

Investigation on the thermal energy storage characteristics in a spouted bed based on different nozzle numbers

The Design and Implementation of Blockchain Smart Contract in Hybrid Energy Storage Management of Photovoltaic System