"What is the Disadvantage of Hydrogen Fuel Cells?
Hydrogen Extraction
Despite being the most abundant element in the Universe, hydrogen does not exist on its own so needs to be extracted from water via electrolysis or separated from carbon fossil fuels. Both of these processes require a significant amount of energy to achieve. This energy can be more than that gained from the hydrogen itself as well as being expensive. In addition, this extraction typically requires the use of fossil fuels, which undermines the green credentials of hydrogen."
Source:
https://www.twi-global.com/technical...gen-fuel-cells
Those who claim that hydrogen is the future of fuels for: "trains, planes and automobiles" do not know physics and chemistry.