Optimization Method for Economical Operation of SOEC Considering Thermal Balance Efficiency Characteristics

The global consensus holds that water electrolysis from renewable energy sources is the primary source of lowcarbon hydrogen supply in the future. Solid oxide electrolyzer cell (SOEC) with high efficiency, simple structure, flexible operation, and environmental friendliness has become a hot topic in green hydrogen research. This paper focuses on the thermal balance characteristics of the SOEC. An efficiency-power model that considers the thermal balance of the SOEC system with renewable energy sources is established. Then, the optimization method of SOEC operation by controlling the electrolysis current and water flow is proposed to maximize operating profit. The proposed model and method are verified by an example of wind plant data in the Gonghe basin of Qinghai Province. Moreover, the optimal electrolysis current and water mass flow values under the SOEC economic operation strategy are analyzed. The results show that the operation optimization method obtained by considering the thermal balance characteristic of the SOEC efficiency-power model can ensure the economical of SOEC while flexibly controlling the efficiency, which provides a helpful reference for the economic operation strategy of SOEC in practical engineering.