Green ammonia is a promising energy and hydrogen carrier and a potential building block in a future, sustainable energy and raw material system. However, the production process requires a high amount of renewable energy. Since potential sites are most often located in remote areas with insufficient grid connection, islanded concepts based on intermittent renewable power generation are receiving a lot of attention. For such concepts, the part‐load behavior of the applied electrolysis technology is of major importance for cost‐effective operation. Within this study, a techno‐economic evaluation of an islanded electrolysis‐based ammonia production for a Western Australian location is performed. A special focus is laid on different part‐load scenarios accompanied by a comparison of different electrolysis technologies. For this purpose, an extensive process simulation integrating electrochemical cell models as well as considerations of different turn‐down capabilities is presented. The results indicate a superior efficiency of solid oxide electrolysis (SOEL) with up to η process = 64. 3% in full load operation compared to ammonia production based on proton exchange membrane electrolysis (PEMEL) only achieving η process = 56. 0%. Even in scenarios with high shares of part‐load operation, SOEL allows for an efficiency of η process = 63. 3%. From the subsequent economic modeling considering development of electrolyzer equipment costs and stack lifetime for future scenarios, net production costs (NPC) for islanded ammonia production were derived. With NPC = 1084 US/ for application of PEMEL and NPC = 1191 US/ for solid oxide electrolysis, islanded green ammonia production was found to be economical feasible in the mid‐term, highlighting the resilience regarding production cost and high planning reliability compared to conventional ammonia production.
Gallwitz et al. (Wed,) studied this question.