Hydrogen

My main issue with hydrogen is that even if you manage to get it stored in liquid form (which is very energy intensive) and can start making it with renewables (perfectly possible, but requires a lot of energy and is often a very energy lossy process), you basically have to make it on site because there are a lot of issues with storing and or transporting it. Hydrogen atoms are so small, that if you are simply transporting it via pipe, there is going to be some leaking. Then you have to deal with embrittlement of any storage tanks which means that you need to replace storage pretty often on pretty much any vehicle that uses it. Personally, I do agree that a net zero fuel is probably more useful for the short/medium term in a lot of transport industries over batteries, but something like methanol would probably be far easier to phase in.