Energy density of hydrogen per litre is few orders of magnitude lower than that of petrol. Really the only saving grace of hydrogen
vs batteries is the speed of refueling.
I think molten salt (latent heat) batteries could push the boundaries further as researchers continue to design salt mixtures with lower melting points and higher and higher delta_k's (economic considerations of compounds included).
Though for usage in cars would imply some kind of small/portable vacuum storage tanks and a way to put the heat to work (most likely initially through a steam engine and eventually directly to electricity via advanced thermocouples[0])
> Really the only saving grace of hydrogen vs batteries is the speed of refueling.
And range, weight, and (eventually) price. Batteries need to improve in all these areas.
Fuel cell cars are expensive at the moment because they're produced in such low volumes. But Toyota thinks that if they produced FCEVs at scale they could build them cheap:
Toyota is the only company pushing hydrogen as a fuel for cars, and it's puzzling why, because they really don't have many advantages, and a ton of disadvantages compared to BEVs.
Everyone else is working on BEVs, including the Chinese.
Am I misreading the gp's cited chart? According to that, it seems like hydrogen is only a factor of around 4x worse in terms of volumetric energy density, and is better than petrol in weight density.
Weight density doesn't help you in a car; these aren't rockets where most of the weight of the vehicle is fuel. In a car, the weight of the fuel is barely noticeable. What's much more important is the size of the tank, and a hydrogen tank takes up a lot of room (to get decent range), and is also quite heavy to contain a pressurized gas that literally leaks out constantly because its molecules are so small.
Still better than current batteries. You could pump that up if you store it in a liquid state to a level above common fossil fuels. Not saying you don't open a can of worms for implementing it...
Hydrogen in liquid state leaks out of any container that you put it in. 70kg lead bottle stores only 1L of hydrogen and all of it evaporates naturally in 1-2 months through the metal. So no, storage of liquid hydrogen is a terrible idea.
It does diffuse through everything, but there are several research projects in that direction. It is the smallest element and it helps if that bottle is solid, but I still see potential.
Besides in-vehicle storage being completely infeasible for many reasons, how exactly do you propose to safely allow consumers to refill a tank with liquid hydrogen? They use it for rockets sometimes, but it's handled very carefully by highly trained technicians under very controlled conditions and the fueling procedure is nothing like a stop at your local gas station.
Dont you forget something- hydrogen if hydrolizes takes place in situa - aka directly below a windpower or solar-plant, has the lowest conversion loss right there.. Also storage can be improved by now chemically - meaning you bind it to a
https://en.wikipedia.org/wiki/Hydrogen_storage#Liquid_organi...
and reduce that to a nearly solid material with extremly high energy density. Its okay to be a tesla fanboi, its not okay to propagate ancient technological "insights".
