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With the significant increase in social electricity consumption, the volatility and uncertainty of the electricity load have a significant influence on the operation of the coal-fired power plant. To address this issue, a novel compressed air energy storage system integrated into a coal-fired power plant is proposed to realize that excess electricity is stored at off-peak time and discharged to the customers at peak time to increase the profit. The double parameters regulation method is adopted to broaden the operating ranges of the compressor and expander. Additionally, the relationship between charging and discharging cycles and the system performance is obtained by analyzing the dynamic characteristics of the packed bed. The simulation results indicate that the operating ranges of the compressor and expander are increased to 63.1–121.6 MW and 12.3–53.7 MW, respectively. Furthermore, the round-trip efficiency and total heat storage capacity of the packed bed gradually stabilized at 54.3% and 650 MWh as the number of cycles increased. The economic analysis shows that the levelized cost of electricity and dynamic payback period of the system are 92.35 USD/MWh and 8.4 years. Finally, compared with previous literature by fuzzy evaluation, the proposed system obtains the optimal membership degree of 0.99. [Display omitted] • Compressed air energy storage coupled with coal-fired power plant is proposed. • Flexible purchasing-selling electricity strategy is used to maximize economy. • Operating range of compressor and expander is widen by novel regulation method. • Some of energy storage systems are evaluated by fuzzy evaluation. [ABSTRACT FROM AUTHOR]

Coal-fired power plants (CFPPs) not only bear the burden of peak shaving, but the mission of energy saving. However, the increasing peak-valley difference leads to the difficulties of peak shaving and the energy waste caused by the ineffective utilization of waste heat, which undoubtedly becomes a new problem for CFPPs. So, a new integrated system combining flexible energy storage and waste heat recovery in the CFPP is presented. The scheme consists of a double-effect absorption heat pump (D-AHP) with an integrated thermal electricity storage system (IT-ESS). Waste heat from flue gas is recovered by D-AHP, while IT-ESS is responsible for peak shaving. Firstly, comprehensive satisfaction is used for demand-side management. Subsequently, D-AHP is utilized to recover waste heat to meet the users' heating demand. Finally, steam is extracted during off-peak time to store energy for IT-ESS, while energy is released for peak shaving during peak time. Throughout the process, the proportional-integral-differential is applied to control the airflow into the IT-ESS. Numerical results indicate that the maximum peak-valley difference is decreased by 55.3 MW after the optimization of comprehensive satisfaction, and the response time for the airflow to reach the target value is only about 10% of one period with the PID control strategy. Besides, the scheme successfully satisfies the electricity demand and heating demand in isolated microgrids, and the round-trip efficiency of IT-ESS is 23.11%. Lastly, the daily revenue of the system is 1.40 million dollars and the payback period is 3.16 years. [Display omitted] • A new design of flexible energy storage combined with waste heat recovery is proposed. • Peak-valley difference of load is reduced after applying comprehensive satisfaction. • The integrated thermal electricity storage system is applied for peak shaving. [ABSTRACT FROM AUTHOR]

Energy storage system is an important component of the microgrid for peak shaving, and vanadium redox flow battery is suitable for small-scale microgrid owing to its high flexibility, fast response and long service time. Therefore, a microgrid based on vanadium redox flow battery is studied for rural applications in this paper, in which biomass gasification and solid oxide fuel cell are integrated as power generation units to provide stable electricity. A predictive control method is presented to improve the efficiency of flow battery and the economic feasibility of this system is evaluated. The mathematical model is validated with the experimental data of published literature. The results indicate that controlling the electrolyte flow rate according to the current and the state of battery can reduce the energy loss of flow battery. The optimal electrolyte flow rate is determined by predictive control method, which can significantly improve the performance of flow battery compared with previous method. The overall efficiency of battery for peak shaving is achieved by 84% and the pay back period of this microgrid system is 7.33 year. [Display omitted] • A stable and high-efficiency power generation system is proposed for microgrid. • Predictive control method is presented to improve the efficiency of flow battery. • The efficiency of flow battery in a complete charge-discharge cycle is 84%. • The payback time of this microgrid is 7.33 year based on time sharing tariffs. [ABSTRACT FROM AUTHOR]

To advance sustainable development and emission reduction efforts within the maritime industry, a novel combined cooling, heating, power, and storage (CCHPS) system is proposed. This system comprises a cogeneration system (ORC + ARC) and a thermal energy storage (TES) system. Initially, optimal working fluids are selected for the ORC and TES discharge systems. Subsequently, an analysis is conducted regarding the correlation between sensitivity parameters and system performance. Then, the cogeneration system's optimum design parameters are determined utilizing the multi-objective grey wolf optimization (MOGWO) algorithm. Finally, the TES system is analyzed and matched with the diesel generators to meet the ship's electricity demand. The CCHPS system achieves optimal thermal efficiency, payback period, annual CO 2 emission reduction, and annual fuel savings of 30.07%, 6.22 years, 8910.49 tons, and 2791.74 kL, respectively. In contrast to the TES-absent system, the CCHPS system exhibits a 12.88% increase in thermal efficiency, along with a 25.48% improvement in annual fuel savings and annual CO 2 emission reduction. [Display omitted] [ABSTRACT FROM AUTHOR]