These problems are grossly exaggerated in popular discussions. Hydrogen has been routinely transported and stored in standard steel cylinders for over a century. Most cities originally used coal gas (50% hydrogen by volume) for heating and illumination before switching to natural gas after World War II. What kills the idea is the abysmal efficiency of electrolysis and hydrogen fuel cells. Standard high-voltage DC power lines would be much better suited for getting solar power from Arizona to Alaska.