It seems like everything is going green these days
but there's one mode of transportation
that seems to be clinging
to the traditional, fuel-loving ways.
And while commercial aviation has made strides
through smarter design and cleaner engines,
many of those gains have been nullified by
more air traffic.
The challenge is enormous.
This is a large industry.
It will take decades to convert.
The good news is that we will have a solution as early
as three years out that people can get into
and start moving zero emission.
And it turns out that the solution
could be all around us.
Hydrogen is the most abundant element in the universe.
And so if you had to use something, it would be great.
The only product of the chemical reaction
between hydrogen and oxygen is water.
We looked at the fundamentals
of what it would require to take an aircraft up in the air
of significant size, over significant distance,
commercially relevant.
You get your hydrogen fuel cell being the best approach
from the cost of fuel, efficiency of
utilization of the fuel
and the mitigation of the climate effects.
Serial cleantech entrepreneur Val Miftakhov
started ZeroAvia following his previous success
in the EV charging industry.
So the beauty about hydrogen in general is
that the energy density of hydrogen as fuel
is actually three times better than jet fuel.
So you can see any size of
aircraft going for any distance
that jet fuel aircraft can go over time.
It will just take significant amount
of time to get the industry over,
but this technology can scale to all sizes
of aircraft that we use in commercial service.
ZeroAvia uses a hydrogen fuel cell
to produce electricity to turn a propeller.
Unlike a traditional engine which uses combustion
to create energy, a fuel cell generates electricity
through an electrochemical reaction.
In this case, hydrogen and oxygen are combined
to generate electricity, heat and water.
ZeroAvia has flown a six-seater aircraft
on a hydrogen fuel cell; a world first.
Now they're aiming bigger, at 20 seats.
That's technically commercial.
One side of the aircraft, the left side, will replace
the engine with our power plants.
We still got a normal engine on the right side.
And part of this is, in aviation you want to ramp up
risk profile in meaningful steps.
So anything happens, we have the second engine.
But even in the first flight test campaign,
what we're planning to do is to demonstrate operation
of this aircraft purely on zero emission power
on the left side engine.
Once we take off, we're able to switch over
to completely zero emission power.
Hydrogen is used throughout all sections of a flight,
that maximizes the efficiency of the entire operation
that reduces the weight, provides for best sort
of mission capabilities, payload and range.
Building power plants and fuel cells is one thing,
creating a whole new infrastructure
for supplying hydrogen is something entirely different.
In automotive a big part of the reason
why hydrogen did not take off is
because the fueling infrastructure needs
to be so distributed.
For let's say, United States,
you have a hundred thousand fueling stations.
Compare that with aviation where 95% or more traffic
in the United States is concentrated in 100 locations.
So that's a three order magnitude difference
which makes build out of the infrastructure much simpler.
It's much larger, much more concentrated stations,
but they're much fewer in quantity.
Calling it simpler might be underselling the challenge
of distributing hydrogen, which unlike other fuels
that can be easily transported in liquid form,
is usually found instead in a gaseous state.
How do you get the hydrogen from point A to point B?
We don't have pipelines from moving hydrogen around.
We don't have all the specialized trucks
to move them around
and so we got thinking, we need a solution
that can be a low capital expenditure solution
and that's the genesis of the company.
John-Paul Clarke is the co-founder
and Chief Innovation Officer of Universal Hydrogen,
a startup that has designed a modular tank system
for the domestic turbo prop market.
Like ZeroAvia, it allows for retrofitting planes
already in use.
Each module has two capsules
and so what we do is load it into the aircraft
as if it was cargo, strap it down,
connect it to the aircraft, close the loading door,
and that would be it.
When you get to your destination, you'd basically unload it,
put it back in a truck, send it back to the production site
to get refills.
We needed to basically come up with something
that could both fit in containers
and also fit in the aircraft, not require increases
in the maximum takeoff weight of the aircraft.
This compromise is one of the biggest hurdles
that may prevent widespread adoption of hydrogen.
Obviously, you're gonna have to take out some seats
because the energy density of hydrogen is less
than jet fuel and you can't store it
in the wings practically, so you're gonna have
to take away some space in the fuselage.
In the ultra-fine margins of aviation,
removing 10 to 20% of your seats is a tough ask,
but that hasn't deterred startups
like ZeroAvia or Universal Hydrogen.
The maintenance cost of a fuel cell motor system goes down
and it goes down significantly, because motors
and fuel cells have much fewer moving parts
than a gas turbine engine.
And so the wear and tear is much lower
and therefore the time between overhaul is longer.
And so when you put all that together, our numbers indicate
that the CASM, Cost per Available Seat Mile,
actually goes down slightly or is at the worst equivalent
to what you have now.
So what you'll have is a smaller cabin
or smaller number of seats.
However, the cost for each of those seats
to operate it is the same or better with the hydrogen.
Like ZeroAvia,
Universal Hydrogen is also working on engines,
successfully testing their two megawatt iron bird
that will allow them to retrofit planes carrying up
to 55 passengers.
ZeroAvia is aiming
for their first commercial hydrogen electric flight
between London and Rotterdam with their 19-seater
by around 2024.
But much like the range anxiety that has plagued
some battery-powered electric vehicles on land,
hydrogen fuel cells are also fairly limited.
At this point, they still don't have the capacity
to power a common 100-passenger jet.
Beyond fuel cells, however, there is another hope
for our lightest, most abundant element:
Burning it.
The first eureka moment, I suppose, is when we saw
steam in the exhaust
because we are thinking to ourselves, "Huh?
We're burning something here when you're producing
absolutely no CO2."
An expert in gas turbine combustion,
professor Bobby Sethi leads research
at Cranfield University in the U.K.
Built on a former RAF base,
the college runs multiple aeronautical programs.
But what Bobby is focused on is burning hydrogen,
as cleanly as possible.
So what we are trying to demonstrate
in this rig is how we can conceive
some hydrogen combustion technologies that can be integrated
in the next generation aircraft engines,
which will deliver not only zero CO2 emissions,
but also ultra-low NOx emissions.
NOx or nitrogen oxides are a significant source
of air pollution globally.
They're the dirty particulates that cause smog in cities,
usually spat out by diesel cars, scooters and buses.
Hydrogen is characterized
by much wider flammability limits,
which means we can go to much leaner combustion.
And as a result, we can burn
at much lower flame temperatures and that's better
for reducing NOx emissions.
Going leaner means burning fuel with an excess
of air in the engine.
Using something like gasoline, lean burn emits
far fewer hydrocarbons.
Doing it with hydrogen also delivers cleaner emissions.
While NOx is a pollutant, hydrogen combustion produces up
to 90% less nitrogen oxide than kerosene.
So while burning hydrogen isn't technically as clean
as using it inside a fuel cell,
it's still a huge improvement over jet fuel.
Unfortunately, like any radically new idea,
there are other potential byproducts of the process
that aren't fully yet understood.
NOx is clearly one of the main emissions we need
to consider, but the aviation community
is also asking themselves and the community in general,
what about all the water vapor emissions?
And some studies have shown,
albeit there's still a large degree of uncertainty about it,
that contrails and cirrus clouds
that may be induced from contrails could contribute
to global warming about four times the amount than CO2 does.
We know that if we are going to be burning hydrogen,
we are going to produce much larger amount
of water vapor emissions.
And if we are going to be producing a much larger amount
of water vapor emissions, then the propensity
for contrail formation is also going to increase.
In spite of all these challenges,
hydrogen is being taken seriously
by the broader industry.
Companies like Universal Hydrogen
and ZeroAvia are gaining the attention of investors looking
for viable and eventually profitable solutions.
Industry giant Airbus wants
to introduce a hydrogen-powered passenger aircraft by 2035.
Recently announcing plans
to retrofit a gas-guzzling Superjumbo
with a hydrogen-burning engine.
The modified aircraft will add a fifth engine,
adapted for hydrogen, and will be mounted
on the rear fuselage.
The A380 is the largest passenger aircraft in existence,
so it offers plenty of room
to store the 400 kilograms of hydrogen.
The company's designs for a blended wing concept
to store extra hydrogen also offer a glimpse
of our flying future.
Apart from the complex engineering challenges faced
by airplane manufacturers, there are also difficulties
in production of hydrogen itself.
Nowadays, most of the hydrogen used in fuel is derived
by splitting it off from molecules of natural gas.
But that requires a good deal of energy
and also produces carbon dioxide.
To make green hydrogen, the electricity used
to run the electrolyzer must come
from a renewable resource,
which is currently a lot more expensive.
As with any new technology however,
initial costs are daunting,
but time may be the best remedy here.
If you look at economics of hydrogen fuel production,
for example, versus fossil fuels, for instance,
the cost of hydrogen is all based
on capital expense and very little operating expense.
So it's sort of similar to solar power.
You put solar panels out there,
and they produce power for 20-25 years.
The operating expense is relatively low.
What that means is that as scale grows,
as we've seen with the solar panels,
the cost of output drops dramatically.
So the first phase is not about
the most efficient aircraft.
It's not about the aircraft
that will deliver the lowest NOx emissions.
It's about demonstrating
that we can carry hydrogen safely on board,
we can burn it safely on board,
and can be used to fly a passenger aircraft.
The key thing is that we don't try to put everything
in the first generation
or we're just gonna delay the entry into service.
So to try and keep it as simple as possible.
If there are some questions on the margin,
they're all in the sort of business model
and market adoption realm.
It is very hard to create a
technological argument
or impossible to create a technological argument
that says, "Well, it's not gonna work."
It is going to work.