Comparative energetic studies on liquid organic hydrogen carrier: A net energy analysis

Energy storage have attracted attention to compensate for the mismatches of electricity supply and demand caused by renewable energies. A regenerative hydrogen fuel cell (RHFC) system composed of an electrolyzer, hydrogen storage, and fuel cell is a promising large capacity energy storage technology. A liquid organic hydrogen carrier (LOHC) is considered for hydrogen storage technology because of its advantages of good safety, easy handling, and high storage density. In this original research, a comparative energetic study on LOHC and other hydrogen storage technologies was conducted using net energy analysis to quantitatively compare various hydrogen storage technologies. First, the basic RHFC system was modeled by a 0-dimensional simulation, and the system efficiency was analyzed. Then, a net energy analysis was conducted by evaluating energy stored on investment (ESOI_e) values. The RHFC system with LOHC showed a higher ESOI_e of 53 for weekly (<100 h) and 18 for monthly (<1000 h) energy storage than other energy storage technologies due to the low embodied energy cost of LOHC materials. Based on the analysis, the RHFC system with LOHC was concluded to be an attractive option for weekly and monthly energy storage of the both wind and solar power.