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The development and utilization of new energy is one of the biggest issues facing mankind. With the rapid development of new energy, its proportion in the power system is getting higher and higher, which will inevitably lead to the increase of the peak–valley difference of the power grid, resulting in a series of stability problems. The connection of energy storage devices to the power grid can not only effectively utilize the power equipment, reduce the power supply cost, but also promote the application of new energy, improve the stability of the system operation, reduce the peak–valley difference of the power grid, and play an important role in the power system. In this paper, the simulation is carried out in PSS/E, and the excitation model and energy storage model are established based on the user-defined function of PSS/E. The particle swarm optimization algorithm is used to optimize the parameters of the excitation system and the energy storage control system, and the performance difference of peak regulation before and after adding the energy storage model and parameter optimization is simulated and compared. Through simulation, the correctness of the user-defined model of excitation and energy storage and the feasibility and superiority of energy storage participating in peak regulation are verified.

The electricity demand is increasing rapidly with the development of society and technology. Coal-fired thermal power plants have become one of the primary sources of electricity generation for urbanization. However, coal-fired thermal power plants produce a great amount of by-product coal fly ash every year. Coal fly ash disposal in landfills requires a sizable space and has negative environmental impacts. Therefore, it is crucial to develop new technologies and methods to utilize this enormous volume of solid waste in order to protect the environment. In this review, the fundamental physical and chemical characteristics of coal fly ash are introduced, and afterward the disposal policies and utilization ways of coal fly ash are discussed to gain a comprehensive understanding of the various ways this waste. The leaching of valuable metals in coal fly ash and the extraction of metal elements in leachate under different conditions are also summarized. Furthermore, the possibility of coal fly ash to serve as a supplementary source for mineral resources is analyzed, providing a basis for its extensive use as a raw material in the metal industry in China and worldwide.

Extracting valuable metals from waste lithium-ion batteries is beneficial to the long-term growth of social economy and environmental maintenance from lithium-ion batteries, yet it faces serious challenges. The study aims to propose a harmless and efficient electrolysis method for selectively preparing nickel products from lithium-ion batteries leachate by controlling the competitive reductive order for Ni2+and H2O. Compared with current pyrometallurgy, hydrometallurgy, and bio-metallurgy methods, electrolysis method allows selective preparation of different nickel products. No additional chemicals are introduced, or no membrane limitation. Achieving zero pollution emissions while saving costs. The results of serial experiments show that the level of nickel reduction can be controlled to produce different types of nickel products. The current efficiency reached a maximum value of 84.7±4.5%. 125 A/m2, 0.05 M Ni2+, 1.5 h, 60 A/m2, 0.1 M Ni2+, 2 h, 125 A/m2, 0.25 M Ni2+, 2 h are the optimal conditions for forming Ni(OH)2, black powder Ni and silvery flake Ni, respectively. In electrolysis process, selective nickel products, H2and O2can be prepared. H2can be used as clean energy and increases economic benefits. This study provides a clean and high-efficiency method for selectively preparing nickel products from lithium-ion batteries leachate.