Study on Optimal Configuration of Hydrogen Energy Storage IES with Dual-fuel Cells

Hydrogen energy storage integrated energy system (IES) can achieve large-scale conversion of renewable energy through electrolysis hydrogen production, and obtain considerable carbon emission reduction benefits through the application of fuel cell technology. However, the performance of traditional single fuel cell system is limited by the operating characteristics of fuel cells. In this paper, a dual-fuel cells hydrogen energy storage integrated energy system combining SOFC and PEMFC was proposed to leverage the complementary advantages of the two fuel cells. In order to ensure the coordinated operation of all the devices, with economy as the goal, the capacity of devices in the system, especially the hydrogen energy storage unit and two kinds of fuel cells, was optimized by considering the annual investment cost, operation and maintenance cost, energy purchase cost and carbon emission cost. The results of case study showed that there was an optimal capacity configuration for dual-fuel cells, which was more economical than the two fuel cells alone. Finally, through sensitivity analysis, the key factors affecting the optimal configuration of hydrogen energy storage unit and dual-fuel cells were pointed out. In dual-fuel cells system, the capacity of hydrogen storage unit and SOFC increased with the increase of electricity price and decreased with the increase of natural gas price, while the capacity of PEMFC configuration was less affected by the purchase price. At the same time, the installed capacity of renewable energy would significantly increase the configured capacity of hydrogen energy storage units, and the capacity change trend for PEMFC and SOFC was opposite.