The roundtrip energy efficiency of such a system is less than 50%, and hydrogen is a very inconvenient liquid fuel (it requires cryogenic storage, very strong p

The roundtrip energy efficiency of such a system is less than 50%, and hydrogen is a very inconvenient liquid fuel (it requires cryogenic storage, very strong pressure vessels, and it leaks away rapidly). There are likely better ways to convert energy into a tractable liquid fuel.