Hydrogen has been used to get rockets to orbit. The thermodynamics make lots of sense. It's the pressures and temperatures at which you need to store the hydrog

Hydrogen has been used to get rockets to orbit. The thermodynamics make lots of sense. It's the pressures and temperatures at which you need to store the hydrogen that make it hard. Synthetic methane might be a much more practical fuel. That too is used for rockets and storing it is much easier. The reason it is a preferred fuel for lots of new rocket companies is that it is easy to handle and still has excellent energy density. Which is important if you are trying to get a few tonnes of useful payload to orbit. The reason the aviation industry is dragging its feet with hydrogen is that they are currently making money with selling kerosene burning jets. The transition away from that is going to be very disruptive for them as they'd be killing the thing that makes them money now. So, like some ICE car manufacturers, they study hydrogen endlessly without ever really committing to doing anything with it. They are not in a hurry. Methane, which I mentioned before, works fine in jets. There have been flying prototypes using that as a fuel. It might be much more practical than hydrogen even. And it can be synthesized just like hydrogen. The latter is often actually synthesized from methane. That's currently the cheapest way to produce it. Energy is not going to be scarce but abundant and dirt cheap long term. You are confusing the short term shortage of fossil fuels with the long term growth of renewables. We're not running out of wind and solar basically. And we are long past the point where exploiting either economically is a problem, even when you consider necessary storage mechanisms. The main thing we are short of here is production capacity, which is growing very rapidly.