Sustainable Hydrogen Production from Offshore Marine Renewable Farms: Techno-Energetic Insight on Seawater Electrolysis Technologies

TLDR

Hydrogen production with offshore marine renewable energies may play an important role as an energy vector and fuel in the future. This study reviews all sea‑based electrolysis technologies and compares their energetic and environmental performance. The review details damage mechanisms from seawater impurities and models three hypothetical plants to produce 350‑bar hydrogen using the examined electrolysis technologies. The results indicate that low‑temperature electrolysis technologies are the most sustainable and durable options, achieving a specific energy of 175 MJ/kg for 350‑bar hydrogen under steady‑state operation.

Abstract

Hydrogen production with offshore marine renewable energies may have an important role in the future as an energy vector and as a fuel. In this regard, this work reviews all the technologies capable of performing electrolysis at sea. The review includes a thorough description and explanation of all known possible damages to the different electrolysis technologies caused by the impurities that may be present in water sourcing from the sea. In addition, this work studies three different hypothetic plants based on the reviewed technologies, to produce hydrogen at 350 bar for its transportation in compressed state. The study is aimed to make an energetic and environmental comparison. The results show that low-temperature electrolysis technologies are currently the best possible candidates regarding both sustainability and durability, with an estimated specific energy to produce hydrogen at 350 bar of 175 MJ/kg under a steady state operation.