Powering renewable hydrogen production with alternative water sources: Is it economically feasible?

Abstract

Limited access to freshwater is a barrier to implement water electrolysis processes regardless of the availability of renewable energy sources. The present work aims to evaluate the economic potential of green hydrogen production using high-quality water produced from alternative water sources. Specifically, the study focuses on two scenarios where desalted water for the electrolyser is produced from either treated urban wastewater or seawater using membrane technologies. The results illustrated that the water reclamation scheme featured substantially lower costs (0.81–1.02 €/m³) than the seawater desalination plant (1.09–1.58 €/m³). However, implementing a water production process before the electrolyser only represented a minor impact (< 2.4 %) on the levelized cost of hydrogen (LCOH) and specific energy consumption of the integrated system, even with water production costs as high as 10 €/m³. The contribution of the specific water consumption to the LCOH ranged between 0.10 and 1.80 % when considering water consumptions between 9 and 15 L/kg_H2, respectively. The sensitivity analysis illustrated that the impact of water production on the LCOH was nearly negligible when compared with other operating factors, such as the electrolyser efficiency or the load factor. Overall, this study highlights that water production from alternative water sources has a minimal impact on the economic balance of the electrolyser, making it a viable option to support green hydrogen projects in water-scarce regions.