Hydrogen liquid is not low energy density, it stores about 140 megajoules per kilo. That’s pretty good storage. I bet you could launch someone to the Moon with that kind of oomph!
I’m not considering political correctness, just using engineering, or I’d bring up the Horrible Number Of Birds that get Shredded By Wind Turbines, let alone the longterm effects of sapping atmospheric kinetic energy directly to wasteful human energy! Might accelerate Global Climate Change donchano.
Yes, H2 is dangerous to work with, but not impossibly so, we’ve built an entire society around the poisonous and explosive gasoline. Hydrogen does not spontaneously ignite, it takes an ignition source. The LEL-UEL is broader than, say, propane but the problems are similar.
I’m not sure about the overall efficiency- I think it may be higher. Wind turbines these days extract a lot of kinetic energy from moving air, and electrical generators are way over 80%. Since the turbine does not “use anything up” other than kinetic energy, the first-step efficiency is not much of an issue. Later stages like kinetic-to-electric are important as you point out. The electrolysis is governed purely by the thermodynamics, and runs between 80-95%, the loss showing up as heat and delta-S. You lose delta-S on recovery, too, so the overall efficiency is probably between 30-55%, better than for petroleum run through an IC engine.
Wind energy is not inefficient, just variable.
Hey, you don’t like wind. I understand that, fine by me.
Its light but its also bulky. 3.4X lower energy density per volume than gasoline.
Volume is a concern when you are worried about hydrogen embrittlement of the container.