For the first time, a comparative economic study between liquid hydrogen and methanol as hydrogen vectors for the bulk transport of hydrogen at sea has been performed. The objective of this study is to gain insight on whether it is costeffective to produce green hydrogen locally or, instead, import it from another location overseas featuring lower costs of renewable energy. In addition, this study aims to determine the break-even point at which the hydrogen transport alternatives, covered in this study, become more inexpensive. The alternatives covered include the seaborne transport of liquid hydrogen or methanol with the reconversion to hydrogen at the destination through methanol electrolysis or a steam-reforming process. Three different production mass flow rates of hydrogen at the origin are explored, 100 kt/y, 1 Mt/y, and 10 Mt/y, in regard to three representative routes: Brazil−Spain, Brazil−The Netherlands, and Australia− Japan. The findings of this study suggest that for the production of hydrogen at 1 Mt/y with an electricity cost of 40 USD/MWh, liquid hydrogen is the cheapest alternative with a levelized cost of hydrogen at the destination of approximately 2 USD/kg for all of the explored routes. If the synthesized e-methanol reaching the import destination is directly used as an energy vector, the levelized cost of energy contained in this e-methanol practically coincides with that of liquid hydrogen at a mass flow rate of 10 Mt/y at the origin.

Green hydrogen plays a key role in decarbonizing the economy. However, the best conditions for producing it are often far from consumption places. This work compares three alternatives for large-scale green hydrogen distribution based on the levelized cost of hydrogen (LCOH): the use of green ammonia as a hydrogen carrier, the use of liquid hydrogen, and on-site production. All of the alternatives include production, packing, transport, and unpacking of hydrogen. Results show that liquid hydrogen outperforms the other alternatives in most cases. Only if the renewable electricity price in the destination site and hydrogen demand are low enough does on-site production become attractive. A demand of 1 MtH2 /y leads to a LCOH equal to 5.14 USD/kgH2 when imported by ship as liquid hydrogen from 7,200 km away and considering electricity prices of 40 USD/MWh in the production site and 100 USD/MWh in the destination. Analogously, LCOH is 9.01 USD/kgH2 when produced in situ and 10.25 USD/kgH2 using ammonia as a hydrogen carrier. The ammonia alternative is attractive if ammonia is the desired good at the destination, or when it does not matter to import any of both fuels from the levelized cost of energy viewpoint. Blue hydrogen LCOH is estimated to be 65% cheaper than green hydrogen under similar scenarios.