hello everyone and welcome in this video we are going to be talking about why hydrogen combustion engines are a dumb idea they’re very cool engines uh unfortunately they’re not the smartest way of using hydrogen for transportation so in this video we’re going to be looking at two key differences between a hydrogen combustion engine and a hydrogen fuel cell and why using a hydrogen combustion engine maybe isn’t
the smartest thing to do now if you
haven’t yet you certainly don’t have to
but it could be worth checking out if
not now after watching this video my
videos on how a com hydrogen combustion
engine works as well as my video on how
a hydrogen fuel cell works to help give
you some background on what’s going on
between these two different things but
in this video we’re going to get into
two major differences and why using a
hydrogen fuel cell is so much better of
an idea so first we need to talk about
the reactions and so we’re going to be
looking at the process the chemical
process that’s occurring with each uh to
determine you know what’s the advantage
here for fuel cells so ultimately out on
the surface you know the very basic
reaction we have two h2s hydrogen plus
o2 oxygen and then we end up with two
h2o so from our hydrogen combustion
engine our only emission is water that
sounds awesome with a fuel cell uh your
reaction same thing two h2 plus o2 gives
you two h2o your only byproduct is water
awesome if both of these were true
that’d be wonderful no difference
between the two unfortunately with this
hydrogen combustion engine because you
have the heat of combustion that’s what
you’re using
to create that mechanical energy you’re
using heat and then you’re pressing down
that piston the heat in that combustion
chamber excites these
oxygens and nitrogens and they combine
together and they form these nitrogen
oxides so that’s the bad news you don’t
want to form nitrogen oxides they’re
terrible for your health they’re not
great for the world you don’t want them
the good news is there’s no carbon
introduced in this equation so you don’t
have any carbon emissions but
unfortunately you are producing nitrogen
oxides with fuel cells the equation also
is not as simple as it looks up here so
really what’s happening is you’re taking
your two h2s you are then using a
catalyst to rip away the electrons from
these hydrogen atoms so you’re now left
with four positively charged hydrogen
atoms those electrons go off to do great
things like power your vehicle or you
know whatever else they’re going to
power and then they come back eventually
because they’re very kind so they come
back they reform with that
those h pluses that you have created
earlier and then you introduce outside
air to that equation in that outside air
is oxygen so you take that 4h plus you
add to that the four electrons you add
to that the oxygen and you end up with
two h2o so your chemical process here
you don’t have any nitrogen oxide
emissions you don’t have any carbon
emissions from an environmental
standpoint fantastic because your entire
process all your by-product is just
water great all right so reason number
one fuel cells are better is for
emissions reason number two is for
efficiency and so if we look at a
combustion engine you of course have
your fuel tank that sends fuel to your
engine the engine sends that power
through a transmission that goes to a
differential and then eventually powers
your wheels so gasoline engines hydrogen
engines they’re generally going to be
somewhere in the 25 to 35 percent
efficiency range let’s just assume a
pretty decent estimate that we get 25
efficiency uh once we get to the wheels
so of that fuel energy we have 25 of it
actually helping to move that vehicle
forward
fuel cells on the other hand you start
with a hydrogen tank you send that
hydrogen to the fuel cell that’s where
this reaction right here is occurring
then you create you send those electrons
off to do wonderful things they go to
the converter this is operating
somewhere around about 60 efficiency
some could be better some could be a
little bit worse sending from that
converter to your power control unit
which then goes to your uh motor
your electric motor and then from your
electric motor to your gear reduction
and then you of course do have a battery
and you can help use that battery also
to regenerate uh energy so when you’re
slowing down you can recover some of
that energy
another efficiency benefit of using it
in this style here with that hybrid
style with the battery there so you’re
basically you have an electric car
that’s powered by using hydrogen because
you’ve got that electric motor up front
so to the wheels you could be getting
somewhere around 50
efficiency from what you started with
the amount of energy that you started
with and also taking the consideration
that you’re going to get some of it back
as you’re slowing down so
it could be a little bit higher it could
be a little bit lower but let’s say it’s
efficiency so here one of the bad things
about hydrogen is that it doesn’t have a
low energy density by volume so it
requires a large amount of space in
order to have a lot of energy well the
downside to that is it means you have to
have a massive fuel tank if you want to
have a long range so if you have
something like these two vehicles and
one of them is twice as efficient that
means if you want them to both go the
same distance this one’s going to have
to have a fuel tank that’s twice as
large that’s going to take up a ton of
space cargo space passenger space not
good you don’t want that so the
advantage goes here to having a much
smaller hydrogen tank
also you’re instantly doubling your fuel
costs if you’re half as efficient so
you’re going to pay a lot more in fuel
cost hydrogen is quite expensive per
gallon so not a great thing if you know
it’s it’s not very efficient and it has
poor emissions versus something that has
basically no carbon emissions no
nitrogen oxide emissions and it doesn’t
have uh as we were discussing it’s much
more efficient at getting that power to
the ground now of course you know where
that energy comes from is important and
that’s another thing here if this is
more efficient
and hydrogen is very expensive and let’s
say you know in the ideal world you need
renewable energy to be creating that
hydrogen for this entire scenario uh to
be environmentally friendly so you need
half the energy uh and so that means you
have need to have those renewable energy
producing resources if the vehicle is
twice as efficient so you know kind of a
cascading advantage to having a more
efficient drive train you know you’ve
got more passenger space you don’t need
as much energy produced for it you pay
less in transporting it now the one
advantage
that this combustion engine certainly
does have is this type of style right
here generally will cost less but
unfortunately you know compared to a
gasoline engine is it all that much of
an advantage
not necessarily so if you’re going to
use hydrogen it makes a lot of sense to
use it in a fuel cell rather than as a
combustion engine which is disappointing
news for all the car enthusiasts around
the world unfortunate sad quite a bummer
i would love to hear you guys feedback
in the comments below of course if you
have any questions or comments you know
what to do thank you all so much for
watching
