"Tim Streater" wrote in message
.. .
In article , Steve Walker
wrote:
Electric cars are unlikely ever to have sufficiently quick charging and
when they make affordable Hydrogen powered cars, that is when petrol and
diesel will have a viable replacement - assuming enough power can be
generated to release the Hydrogen in the first place.

What is the hydrogen going to be stored in? (when in the car, I mean,
not at the petrol station).

A tank that is *very* well protected against being ruptured in a collision
(hydrogen is highly explosive - R101, Hindenberg etc) and with *very* good
seals to prevent it leaking out of the joints in the pipes between the tank
and the engine (hydrogen is the smallest of all molecules and can escape
through gaps that bigger molecules can't get through).

I'm not sure how much hydrogen a tank can hold, in terms of mass of hydrogen
or range of car, if it is roughly the same size as a petrol/diesel tank to
fit in the same space under the rear seats.

Hydrogen has very high energy density -
https://www.energy.gov/eere/fuelcells/hydrogen-storage says about 120 MJ/kg,
compared with about 45 MJ/kg for petrol or diesel (I was surprised that
there was very little difference between the figures for petrol and diesel).