A review on flexible peak shaving development of coal-fired boilers in China under the carbon peak and carbon neutrality goals

The flexible peak shaving capacity of coal-fired power units has a direct impact on the trajectory of renewable energy in China's evolving energy landscape, and therefore, the achievement of carbon peak and carbon neutrality goals. In this paper, the concept of flexible peak shaving is delineated. The developmental status of flexible peak shaving in China is introduced, and the challenges of flexible boiler peak shaving are summarised. The genesis, principles, efficacy, advantages, and limitations of three technologies, namely, thermohydrodynamic system optimisation, external energy storage system configuration, and control system optimisation, are elaborated. Ongoing research is summarised, and the leading teams in China are highlighted. This review describes five demonstration projects undertaken in China and explains policy support and compensation mechanisms. It is found that flexible peak shaving can be achieved by combining deep and fast peak shaving. The fast peak shaving capacity of China's coal-fired boilers is insufficient, and the primary challenge is the lack of energy supply capacity. For fast peak shaving, external energy storage system configuration techniques such as Ruths steam storage and molten salt thermal energy storage are more appropriate. To improve the enthusiasm for fast peak shaving of coal-fired power units, a national compensation mechanism should be implemented in China.