1.State Key Laboratory of Power System Operation and Control (Tsinghua University), Beijing 100084, China;2.Tsinghua Sichuan Energy Internet Research Institute, Chengdu 610042, China;3.Hydrogen Energy Research Center of Electric Power Research Institute of Guangzhou Power Supply Bureau, Guangdong Power Grid Co., Ltd., Guangzhou 510335, China;4.Beijing Tsintergy Technology Co., Ltd., Beijing 100084, China;5.State Key Laboratory of Internet of Things for Smart City (University of Macau), Macau 999078, China;6.National Engineering Research Center of Chemical Fertilizer Catalyst (School of Chemical Engineering, Fuzhou University), Fuzhou 350116, China

Utilizing renewable energy sources such as wind and photovoltaic to identify cost-effective decarbonization pathways for coastal receiving-end power systems is one of the core challenges in achieving the goals of “carbon emission peak and carbon neutrality” of China. By analyzing the techno-economic differences between hydrogen-ammonia storage and existing energy storage technologies (such as electrochemical and compressed air energy storage), a multi-year expansion planning model for power systems incorporating cofiring coupled hydrogen-ammonia energy storage under temporal decarbonization constraints is established, and the techno-economic feasibility of achieving low-cost decarbonization within the power system is explored. The actual data are selected from Guangdong power grid of China for case study. The results demonstrate that, under increasingly stringent carbon reduction constraints, it is necessary to progressively achieve decarbonization targets through technical pathways, such as the newly added wind and photovoltaic storage, the transition from coal to gas in thermal power planning modes, and the newly added hydrogen-ammonia energy storage (including hydrogen cofiring in gas turbines, ammonia cofiring in coal-fired plants, and ammonia decomposition). Compared with a decarbonization mode relying solely on lithium-ion battery peak shaving, the introduction of cofiring coupled hydrogen-ammonia energy storage technology can avoid overloading excessive wind and photovoltaic storage capacity, thus significantly reducing the wind and photovoltaic curtailment rates. This approach not only achieves intensive resource utilization, but also further reduces the decarbonization cost of hydrogen-ammonia energy storage through the reuse of existing thermal power generation infrastructure. Therefore, the use of hydrogen-ammonia energy storage technology for power system decarbonization presents a scalable and economically feasible decarbonization pathway.