Energy Storage最新文献

The aim of this research was to prepare a microencapsulated thermochromic system capable of thermal energy storage for thermal comfort and sensory applications in textiles and to demonstrate its efficacy when applied to polyester fabrics. Therefore, fluoran dye-based thermochromic systems (TSs) were prepared and microencapsulated in a poly(methyl methacrylate-co-methacrylamide) (PMMA-co-MAA) shell using the emulsion polymerization process. The systems contain a fluoran dye, phenolphthalein (PP), and 1-tetradecanol (TD). Scanning electron microscopy (SEM) images showed that the microcapsules were spherical and homogeneous in size. The microcapsules have a typical particle size of 12–15 μm, making them suitable for textile applications. The latent heat energy storage capacity of the microcapsules was satisfactory, with melting enthalpy values ranging from 144.2 to 176.1 J/g. Thermal gravimetric analysis (TGA) showed that the microcapsules disintegrated in two unique steps. The thermochromicity of the microcapsules was confirmed using a UV–Vis spectrophotometer, and photographic images were taken using a camera. The microcapsules were impregnated into 100% polyester fabric after causticizing and anionizing pretreatments. SEM images of the fabric showed the presence of packed, dense microcapsules within its structures. The fabric sample showed a darker color and improved color homogeneity. The hot-cold color measurements showed a total color difference (ΔE) of 19.08 to 23.97. The fabric sample containing microcapsules has a thermal energy storage capacity of 31.9 J/g when heated to 34.2°C.

Thermal energy storage offers a viable solution to address the global energy problem of balancing the gap between the energy demand and the energy supply. One of the most advanced and mature thermal energy storage technologies in solar power technologies is a Concentrating Solar Power plant with a tower configuration and molten salts as thermal energy storage. Despite their advantages, molten salts also have limitations that include their corrosive nature, solidification at temperatures below 240°C, and high cost. Therefore, alternative thermal energy storage materials, such as solid-state thermal storage using concrete blocks or ceramic particles, are under research. Solid particles have a high thermal energy storage density, comparable to molten salts, and can withstand higher temperatures, making them well-suited for use in Concentrating Solar Power systems. The use of alternative materials for thermal energy storage is an important aspect of the circular economy concept, which aims to extract the maximum value from resources and reduce greenhouse gas emissions. This work aims to test the compatibility of Solar Salt with several alternative materials for use as thermal energy storage media, including silica sand, commercially sintered bauxite, and two different waste materials from the mining and steel industries. The study compares the thermal and chemical properties of these solid-molten salt mixtures with those of Solar Salt and quantifies the formation of nitrites in Solar Salt as a direct measurement of Solar Salt degradation. Additionally, a rheology study was conducted on the Solar Salt samples, revealing slight changes in viscosity attributed to the nitrite content. Although the thermal properties of the materials remained almost identical and natural and inert ceramic materials exhibited good compatibility, Solar Salt in contact with the waste materials exhibited the formation of nitrites, indicating an expected further degradation of the Solar Salt within these compounds.

This study analyzes the impact of using single and multiple circular phase change materials (PCMs) to enhance the performance of an air-conditioning (AC) unit. The technique involves attaching a heat exchanger containing cold energy storage PCM to the air conditioner's condenser. During the daytime, warm surrounding air is cooled and transmitted to the condenser of the air-conditioning system. The computational study is conducted using the SST k –ω turbulence model. The air inlet temperature to the PCM is kept at 308.15 K, and the air flow rate is kept constant at 49 L/s. The findings indicate that, during the discharging process, the complete melting time for the multi-circular PCM increases by almost 72% compared to the single-circular PCM. Temperature contours reveal that turbulence happens in the solid zone, primarily at higher temperatures, within the PCM melting region. This suggests enhanced convection in this region. The fall in the outlet air temperature is greater for the multi-circular PCM relative to the single-circular PCM. The coefficient of performance (COP) increases by approximately 87.57% for the multi-circular PCM system and 7.60% for the single-circular PCM unit during summer. The power saved by the single-circular PCM is about 0.3792 W for 6 h of operation, while the multi-circular PCM saves approximately 4.3821 W.

In Duhok, Iraq, the national electricity grid struggles to meet household electricity demands due to inadequate infrastructure, resulting in frequent power outages. During these outages, households rely on diesel generators to supply electricity, leading to high investment and operating costs. Additionally, diesel generators contribute to noise and air pollution, causing further environmental harm. This study aims to provide reliable, environmentally friendly electricity at lower costs to meet household energy needs. In this context, an analysis was conducted on a hybrid power system consisting of energy storage and an on-grid photovoltaic system, with solar energy as the primary source. The HOMER program was used for these analyses. The results indicate that using an on-grid PV system with energy storage can reduce the cost of electricity from 0.022 to 0.010 $/kWh. The payback period for this hybrid power system is calculated to be 4.56 years. These findings suggest that investing in a hybrid power system represents an excellent economic opportunity for Iraq, particularly considering the local conditions in Duhok.

The increasing need for reliable and efficient energy storage solutions has brought a strong focus on enhancing the performance of lithium-ion batteries (LIBs), especially for high-voltage applications like electric vehicles and renewable energy systems. Active cell balancing is essential for maintaining uniform charge distribution across cells, improving the lifespan, capacity, and safety of LIBs. The paper presents a comprehensive performance assessment of an optimized active cell balancing circuit based on a buck-boost converter. The research work proposes a novel approach for active balancing circuits, integrating advanced control algorithms and high-efficiency power electronic components for efficient and fast results. Simulation studies are undertaken in MATLAB-Simscape to estimate the effectiveness of the cell balancing model. Circuit performance across different load types shows slight variations. For resistive load, balancing occurs in 33 s at 71% state of charge (SOC), reaching 100% SOC in 242 s. For resistive and inductive load, balancing occurs in 32 s at 70% SOC, reaching full charge in 240 s, and for resistive, inductive, and capacitive load, balancing occurs in 33 s at 70% SOC, stretching to 100% SOC in 239 s. The study provides valuable insights into the design and implementation of high-performance active balancing circuits, paving the way for more reliable and efficient LIB packs.

This study estimated the willingness-to-pay (WTP) for the development and promotion of reactive capture and conversion (RCC) technology in South Korea using the contingent valuation method. RCC is an emerging technology that integrates CO₂ capture and conversion processes, potentially offering economic and environmental benefits over traditional carbon capture, utilization, and storage methods. A survey of 1032 respondents was conducted using the one-and-one-half bounded dichotomous choice format with a spike model. The results indicate an average annual WTP of KRW 4697 (USD 3.58) per household per month for 5 years, translating to a total national WTP of KRW 561.65 billion (USD 427.82 million). Demographic analysis reveals that women and residents of metropolitan areas have a higher WTP. Interestingly, the level of prior knowledge about RCC did not significantly affect WTP, possibly due to the prevalent belief that climate change mitigation is primarily a government responsibility. This study provides the first socioeconomic valuation of RCC technology, offering valuable insights for policymakers and researchers. The findings suggest substantial public support for RCC development, highlighting its potential as a key strategy in South Korea's climate change mitigation efforts. However, to increase public acceptance and investment in RCC, there is a need for broader discussions on individual roles in addressing climate change, alongside government initiatives.

This study aims to analyze and enhance the performance of a solar/voltage chimney by incorporating porous media, specifically using a gravel layer beneath the solar panels to facilitate cooling and improve efficiency. The gravel acts as a heat transfer medium, dissipating heat from the panels to the surrounding air, thereby reducing their temperature. A comparative analysis was conducted between systems with and without porous media. The results demonstrated that integrating porous media enhances the performance of the hybrid photovoltaic/solar chimney. Specifically, the electrical energy output increased from 395.56 W without porous media to 447.98 W with porous media at noon. The peak electrical efficiency was observed at the beginning of the test, reaching 14.51% without porous media and 15.22% with porous media at 9 a.m. At midday, electrical efficiency was 11.5% without porous media and 12.2% with porous media. However, as solar radiation intensity increased, efficiency gradually declined. On the other hand, the thermal efficiency of the chimney with porous media was lower compared to the system without it, with values of 53.45% and 59.611%, respectively. The total efficiency of the system without porous media was 65%, while with porous media, it reached 59.611%.

In this work, the structural, electronic, mechanical, and hydrogen storage properties of B₁₂H₂₀N₂ were investigated using first-principles calculations. First, we evaluate the structural stability of B₁₂H₂₀N₂ hydrides using enthalpy of formation calculations. Then, the mechanical stability is specified by the elastic stiffness constants, which reveal that the B₁₂H₂₀N₂ hydrides are mechanically stable because they meet the Born stability requirements. The computed lattice constant of B₁₂H₂₀N₂ agrees very well with the available experimental parameter. The study of the electronic structure and density of states of this material reveals that B₁₂H₂₀N₂ is an insulator. In this regard, B₁₂H₂₀N₂ demonstrated its applicability surpassing that of the U.S. Department of Energy's for 2025. Our investigation predicts the applicability of B₁₂H₂₀N₂ hydride as a promising solid-state compound.