Potential and Role of Seasonal Energy Storage in the Transition of Power and Heating Sectors—a Case Study

Energy storage technologies will play a crucial role in power and heating systems with a high proportion of renewable energy generation, such as wind and photovoltaic power generation. However, in existing research on power system transformation, energy storage modelling has mainly focused on short-term storage methods like pumped hydro storage, lithium-ion batteries, and compressed air energy storage, with insufficient attention given to seasonal energy storage technologies such as hydrogen and thermal storage. In this study, a joint optimization model for long-term planning and short-term operation in the power industry has been applied, and a case study has been conducted on the low-carbon transition pathway of power and heating sectors in China under the carbon neutrality goal. In this model, pumped hydro storage, lithium-ion batteries, compressed air energy storage, hydrogen, and thermal storage were modeled as energy storage technology options, and the planning schemes for the power and heating sectors under carbon emission constraints were quantitatively analyzed. Results indicate that the application of hydrogen and seasonal thermal storage will lead to a reduction in the installed capacity, power generation, and heat supply of coal-fired power plants in 2060, and will partially replace their seasonal regulation functions while promoting the development of photovoltaic. In the future, hydrogen will be characterized by "storage in spring for use in summer" and "storage in autumn for use in winter", with the peak hydrogen storage occurring in May at approximately 6.5 million tonnes. Seasonal thermal storage will be characterized by "storage in spring for use in winter", with the peak thermal storage occurring in October, totaling around 320 million GJ.