November 26, 2018 • 36 mins
Hydrogen is the most plentiful substance in the universe. Could it also be the fuel of the future? In this episode, we look at the challenges and opportunities related to a hydrogen economy.
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Speaker 1 (00:04):
Get in touch with technology with tech Stuff from how
stuff works dot com. Hey there, and welcome to tech Stuff.
I'm your host, Jonathan Strickland. I'm an executive producer and
a love of all things tech. And on November I
ran across an article titled quote can we produce enough
(00:26):
green hydrogen to save the world? End? Quote? And I thought,
I haven't done an episode about hydrogen and the proposed
hydrogen economy for quite some time. It might be a
good sign to revisit this topic and remind everyone what
it's all about, because when it comes to conversations about
transitioning away from a dependence on fossil fuels, hydrogen is
(00:49):
frequently part of that conversation. Today, we're gonna explore why
that is, and whether we can in fact produce enough
of it responsibly in a green way to create a
true hydrogen economy. Spoiler alert, that's just one component of
a hydrogen economy. I'll talk a lot about that in
(01:10):
this episode. First, we gotta just lay some groundwork, right.
Hydrogen is the most abundant element in the universe. It's
what stars are made out of. According to the Los
Alamos National Laboratory, if you were to gather all the
atoms in the universe all the matters. So you've got
(01:31):
all the atoms in the universe all in one room, Well,
it would need to be a really big room, but
more than nine percent of all those atoms in that
room would be hydrogen. So at first you might think
that means we're lousy with the stuff here on Earth,
and we kind of are. But there's some other things
(01:52):
about hydrogen that makes that whole plentiful thing a little
more misleading when it comes to our day to day experience.
So first, pure hydrogen has a boiling point of minus
two hundred fifty two point nine degrees celsius. That's minus
four hundred twenty three point two degrees fahrenheit. That means
(02:14):
anything warmer than that extremely cold temperature will cause hydrogen
to boil off into a gas. To make hydrogen a liquid,
you would have to cool it down to thirty three kelvin.
Zero kelvin represents absolute zero. That's when you essentially have
no molecular movement at all. Absolute zero is colder than
(02:39):
empty space, which is somewhere around two point seven kelvin,
So thirty three kelvin is toasty in comparison, but it's
still colder than anything you're gonna find occurring naturally on
our planet. So on Earth, unpressurized pure hydrogen is going
to be in gas form, and this is a problem
(03:00):
because hydrogen is also the lightest element. The heavier elements
in Earth's atmosphere will push down and hydrogen will move
up higher and higher until it actually escapes Earth's gravity,
so pure hydrogen will float off into space. Capturing hydrogen
(03:20):
from the atmosphere isn't really a practical solution because of this.
So hydrogen also has a strong tendency to bond with
other elements, and that's really another very important thing. So
we can get to hydrogen here on Earth, but it's
bonded to other stuff Like two Hydrogen's can bond with
(03:41):
an oxygen atom and form water H two O. So
more on that in a bit as that's key to
the challenge of making a working hydrogen economy is figuring
out how to get hydrogen out of these compounds and
elements and things, not elements, but you know, mixtures. So
there are three common isotopes of hydrogen. The ordinary, boring
(04:06):
pure hydrogen that we tend to talk about is called protium,
and that consists of one proton that is orbited by
one electron. So the nucleus of pure hydrogen protium isotopes
is just a proton. Then you have deuterium that one
adds a neutron to the nucleus, so now you've got
(04:26):
one proton, one neutron in the nucleus orbited by one electron.
Then you have tritium that's a radioactive isotope and it
has a nucleus with one proton and two neutrons orbited
by a single electron. This stuff does occasionally form in
Earth's atmosphere when cosmic rays interact with the air, but
(04:48):
it has a pretty darn short half life. It's just
half life of twelve point three years. So when you
pair that with the fact that it's super light, so
little eventually flowed off into space. It's also very uncommon
for cosmic ray interactions. They aren't super commonplace. There's very
little chance for any significant amount of tritium to accumulate
(05:11):
in the atmosphere before it decays. Back in sixteen seventy one,
a philosopher and intellectual named Robert Boyle was doing some
exploratory research. He was using iron and dipping it into
different types of acid, and he saw that the reaction
in one of these combinations produced some bubbles some gas.
(05:32):
Many folks will call boil the the father of chemistry,
but at this point his observation mostly just consistent of
it's a gas man, you know anything more about it.
Almost a century later, Henry Cavendish, another philosopher and scientists,
identified hydrogen gas as a distinct element. The French chemist
(05:54):
Antoine la Vasier gave hydrogen its name. Now, the earliest
record I could find of a gas balloon that used
hydrogen as the lifting agent dates to seventeen eighty three
in Paris, but hydrogen was used for balloons and airships
for decades until really the Hidden Hindenburg disaster in nineteen
(06:16):
thirty seven that scared people quite a bit and stopped
a lot of people from using hydrogen as a lifting agent.
Hydrogen gas, by the way, is extremely flammable in the
presence of oxygen. So the Hindenburg caught fire as it
was docking with a mooring mast, and it was a
massive fire. It killed thirty six people, including one person
(06:37):
on the ground. There were a lot of people who
were on the Hendenberg who survived with some with severe injuries.
But still that's a pretty awful disaster. And it was
caught on film and there was a radio uh presenter
who was talking through the whole thing. If you've ever
heard the phrase, oh the humanity that comes from the
(06:58):
Hindenburg disaster, and it truly was a spectacular catastrophe that
tragically killed many people. Now, there are several hypotheses as
to what actually started this fire, but it was definitely
the hydrogen that provided the fuel for it to spread
so quickly and to cause such a disaster. So disasters
(07:19):
like the Hindenburg definitely raised huge warning flags with anything
associated with hydrogen and fuel in many people's minds, and
it persists to this day. There are people who say, well,
we don't want to invest in any sort of hydrogen
approach to energy storage because of the possibility of another
Hindenburg like disaster. Now, in the eighteen hundreds, a mixture
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with hydrogen was used as gas for street lamps, so
it was actually being used as a form of fuel,
And in eighteen thirty nine Sir William Robert Grove would
conduct some experiments that led to the development of hydrogen
based fuel cells. So we'll talk more about fuel cells
in a little bit, But first, burning hydrogen gives off
(08:05):
water vapor and some other trace by products depending on
how you're burning. If you're burning it with pure oxygen,
you get water vapor. If you burn it in atmospheric conditions,
you'll get some small byproducts like various hydrogen oxides. It
all depends upon the composition of the air at that point,
but it does not produce carbon dioxide like burning fossil
(08:29):
fuels does. So it seems like hydrogen would be a
super awesome fuel source for us to go with if
we could be reasonably certain that the method we're using
would contain this reaction and not result in a in
a Hindenburg like disaster. But that's something we can totally do.
We can do that. I mean, cars are driving around
(08:50):
using gasoline as fuel, and gasoline is flammable, So why
don't we just switch to hydrogen. I mean, it's it's
the most plentiful stuff in the universe and it burns lean. Now, granted,
water vapor is a greenhouse gas, we have to accept this,
but water vapor also can incorporate into the water cycle
on Earth and out of all the greenhouse gases. We
(09:11):
actually understand water vapors roll in greenhouse gases the least,
But what's the hold up with hydrogen? While the big
one is that most of hydrogen on Earth is bound
together with other stuff like water that hydrogen and oxygen
or hydrocarbons like the hydrocarbon is an organic compound made
(09:32):
up of hydrogen and carbon. So if you have a
carbon atom and four hydrogen atoms, you would have methane.
To use pure hydrogen as fuel, you first have to
find a way to shake those hydrogen atoms loose from
those molecular bonds. So that means to produce hydrogen gas,
we first have to pour some energy into compounds that
(09:55):
have hydrogen in them to break those molecular bonds. You
gotta come up with a good way to do that
so that in the end of the day, the energy
stored in the hydrogen gas that you have harvested is
more than the amount of energy you used to get
the gas in the first place. Otherwise you have a
net loss and energy. If you pour more energy into
(10:16):
making the hydrogen gas, then you would get out of
consuming the hydrogen gas. You're losing energy. We call this
a bad thing. This is true for all fuels, by
the way. So if it cost us more energy to
get petroleum and to refine that petroleum into fuel, then
the petroleum fuel itself could store we would not be
(10:37):
using fossil fuels to begin with, because we would be
losing energy. We would instead say, why don't we use
whatever it is we are relying upon to get the
petroleum in the first place as our energy source. But
that's not the case. Now. We can measure the energy
content of various fuels by using an apparatus that allows
the fuel to burn under what's called standard conditions. Sanery
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conditions means zero degrees celsius and one bar of atmospheric pressure.
One bar is close to one atmosphere at sea level,
it's actually a little less. A container of water with
a known starting temperature and a known mass will absorb
the heat that's released from this reaction, so you burn
whatever the fuel is. The heat gets captured by a
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known quantity of water that's at a known starting temperature.
You measure the change in temperature of the water, and
that can give you the amount of energy that was
released by this process. Dividing that by the mass of
the fuel that you burned will give you the energy
content of the fuel typically expressed in jewels program or
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or more typically mega jewels per kilogram. This is called
the specific energy of the fuel. Natural gas, which is
mostly composed of methane, has a specific energy of fifty
five mega jewels per kilogram. Get selene has a specific
energy of forty six mega jewels per kilogram, so it's
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not as energy dense in this respect as natural gases.
Coal has a specific energy of twenty four mega jewels
per kilogram. Wood is all the way down to sixteen
mega jewels per kilograms. So what about hydrogen. Well, hydrogen
packs a wallop at one hundred forty two mega jewels
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per kilogram. But hydrogen is a gas, so a kilogram
of hydrogen, the lightest element, is going to be an
enormous volume of gas. The mass is the same, a
kilogram is a kilogram, but the volume the amount of
space it takes up, is different. So this is deceptive.
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We can't just talk about hydrogen the least massive element,
in terms of mass. It makes more sense from a
practical perspective to talk about in terms of volume, because
that's how we're going to handle it. How much energy
is stored in hydrogen for a given unit of volume,
I'll tell you in just a second, but first let's
take a quick break to thank our sponsor. Okay, So
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for practical purposes of using energy storage, we should really
look at how much energy hydrogen has per unit of volume,
not unit of mass. This is truly what we mean
by energy density. So gasoline has an energy density of
thirty four point to mega jewels per leader. Natural gas
has an energy density of twenty two point to mega
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jewels per leader. So we see the gasoline comes out
ahead when we look at it by volume, not by mass.
But what of hydrogen. Well, if you compress it so
that you can put it in hydrogen tanks, you're looking
at an energy density of about nine mega jules per leader.
So you need more leaders of hydrogen than of gasoline
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in order to do the same amount of work when
you're burning it as fuel. In other words, because gasoline
has the energy density of thirty four point two mega
jewels per leader, hydrogen at nine, so that's an issue. Still,
hydrogen would burn clean compared to fossil fuels, so we
would just need to have enough hydrogen to compensate for this.
(14:27):
So how hard is it to get pure hydrogen from
various sources and how do we typically produce hydrogen gas? Well,
right now of hydrogen production comes from wood or fossil fuels,
and the most common process is called natural gas reforming
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or steam methane reforming. This involves exposing methane gas, that
carbon with four hydrogen atoms connected to it, two very
high temperature steam this cause. This is a couple of
successive chemical reactions, and the end result is you get
hydrogen gas and carbon dioxide. This, as you might imagine,
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is a problem because carbon dioxide is a greenhouse gas,
and so is methane actually, and this process creates one
and makes use of the other. So while you could
burn the hydrogen gas and not create any carbon dioxide,
the actual process of producing the hydrogen gas using this
(15:30):
method releases CEO two. So this is a good reminder
that when we talk about alternatives to fossil fuels, we
actually have to look at a very big picture, not
just what happens when we burn the alternative, but how
do we produce the alternative does that in turn create
more greenhouse gases? We have to look at the whole
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chain to make sure we're minimizing the emission of greenhouse
gases and the release of potentially hazardous materials. You can
produce hydrogen safely this way, and even in an environmentally
friendly way. If you can capture the carbon dioxide, if
you have a method of carbon capture and you're able
to capture the CEO two that's being given off by
this reaction, then that might be a good way to
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produce hydrogen. However, adding those components, like the carbon capture components,
increases the expense of producing the hydrogen. It's it's more
expensive to do it that way, and as you add
in the cost of producing the hydrogen, it means that
you're going to have to sell the hydrogen for higher
costs to recapture that and economics plays a very important
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part of this proposed hydrogen economy. If it is not
cost efficient, it is a very hard sell. Money is
another part of the puzzle that we have to manage.
We have to be careful about that. So if it
comes out that fossil fuels are significantly cheaper to produce
and use than hydrogen, it's really hard to get momentum
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to switch from fossil fuels to hydrogen. If fossil fuels
become scarce and therefore become more expensive, or the production
of hydrogen becomes cheaper, then that could provide the economic
incentive to make the switch. Or if the environmental impacts
of using fossil fuels, we're creating expenses that were out
of control. If it were a point where we said
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we have to switch from fossil fuels because dealing with
the consequences of fossil fuel use is getting too expensive,
then we might see a switch as well, but it
would probably be a little late for that. There are
methods of producing hydrogen that don't rely on this approach.
So one of them is that you could take charcoal.
Charcoal is when you really break it down, mostly carbon
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and water when you get down to it. So you
can put charcoal in a very high temperature reactor and
burn charcoal at a temperature between twelve hundred and fifteen
hundred degrees celsius. Doing so well, it will release gas
and that gas will separate out and then reform into
hydrogen carbon monoxide. So yeah, hydrogen, but carbon monoxide is
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toxic to many animals, including us, and it also plays
a part in the formation of smog. So that's not great.
I guess the one positive thing I could say is
carbon monoxide itself is not a greenhouse gas on its own.
But the way that the article I first mentioned at
the top of this episode is really focusing on is
a third method to produce hydrogen. It is one that
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only produces oxygen and hydrogen. Those are the only two byproducts.
It is the process of electrolysis of water, and electrolysis
refers to the separation of bonded elements and compounds through
the use of an electric current. So the idea is,
if you pass an electric current of sufficient strength through
certain materials, you can break the molecular bonds holding the
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atoms of that material together. Pure water, as it turns out,
isn't great for this. You would need a very very
strong current because pure water is a poor conductor of electricity.
What you need are electrolytes in the water. And I'm
not talking about the stuff that plants crave. I'm talking
about the substance that when you put it in water,
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creates an electrically conducting solution. It introduces ions. In other words,
but you need to make sure that whatever electrolyte you
include in the mixture doesn't electrolyze more easily than water does,
because otherwise, what will happen is you put the electric
current into the solution and the electrolytes will electrolyze, whereas
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the water will not, and you won't release hydrogen until
you just have pure water again, and you're back to
where you started. So one of the ions that is
frequently used for electrolysis would be sulfate ions, because sulfate
doesn't electrolyze more easily than water does. So you've got
your water and you've got your electrolytes in it, and
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then you put two electrodes, and one of them is
connected to the negative terminal of the battery. One of
them is connected to the positive terminal of a battery.
I'm just using a battery for this particular example. It
doesn't have to be a battery. So you've got your
negatively charged electrode that's called the cathode, and you've got
your positively charged electrode that's called the anode, and you
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insert them in the water. Now, what will happen, assuming
you've done this correctly, is that hydrogen gas will bubble
up around the cathode, and oxygen will bubble up around
the anode. One of the traditional challenges associated with electrolysis
of water on a large scale is that the electro
catalysts catalysts are things that facilitate the reactions and chemical reactions.
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They make chemical reactions happen more easily or with less
energy if you prefer. The electrode. Catalysts that we tend
to use for electrolysis also tend to be pretty rare
and expensive. Like one of the common ones is platinum,
but platinum is not easy to get. It is rare,
and so it's very costly, and that means the cost
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of building out the system to produce hydrogen will get
driven up. And as I already mentioned, cost is one
of those factors we can't just ignore when it comes
to creating an alternative fossil fuels. So in some scientists
at the University of Houston announced the development of a
new electro catalyst made from a conductive nickel foam material
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and a ferris metaphosphate. The relevant point here is that
this stuff costs less to make than if you were
to go out and get platinum. So this is a
push to make hydrogen production economically viable. And like I
said before, you have to take this big picture into account.
So that doesn't just include the materials you need to
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perform electrolysis on water. You also have to ask where
is the electricity coming from? What is providing the electricity
I'm using for electrolysis. If you trace back the source
of your electricity and ultimately you're drawing electricity from a
coal firing power plant, then you haven't really solved any problems.
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The pollution is still in the equation. It's just over
in the electricity production side as opposed to the direct
hydrogen production side. In fact, depending upon your approach, you
may be consuming more fuel and using up more stored
energy than you are producing by creating hydrogen if you
have a very inefficient system, and you'd be using a
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process that releases greenhouse gases to boot, so that would
be a really bad idea. The article talked about green hydrogen,
and by that they meant using some sort of renewable
energy source to create the electricity, such as wind power
or solar power. That can be a step in the
right direction. If you're using wind power, solar power hydro
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power or whatever, and you're generating more electricity then you
need to supply given area at a given time. Then
if you were to pair those facilities with an electric
electrolyzer facility, electrolysis facility, if you if you will, that
would make a of sense because electricity is a use it,
store it, or lose it commodity. At some point, you
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might be producing more electricity than you need at that time,
and rather than lose it, you can put it to work.
You can take that excess electricity and put it to
work to produce hydrogen. So that article I mentioned at
the beginning of this episode goes into this concept in particular,
and it talks about a project in Len's Austria. That
project is called H two future H two, referring to
(23:30):
hydrogen gas. The goal is not just to create hydrogen
gas using electricity from renewable energy sources, but to use
the hydrogen as a fuel source for steel production. It
would be co located with a steel production plant, so
this would create green steel and steel production usually requires
burning a lot of coal and uh. It turns out
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that steel and cement production together are responsible for about
twenty percent of all carbon diet side emissions in the world,
So if you could bring that down by creating a
hydrogen based steel production plant, you could drastically reduce the
amount of carbon dioxide that's being emitted into the atmosphere.
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I'll talk more about these plans in just a second,
but first let's take another quick break to thank our sponsor.
The H two future project is a small scale test.
So this electrolyzer is paired with that steel plant, and
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it's going to run at a capacity of six megawatts,
which is not particularly powerful in the grand scheme of things.
According to the article I was reading, which is over
on fizz dot org p h y s dot org,
this will result in the production of twelve cubic meters
of hydrogen per hour, and if the test proves promising,
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the plant could invest in building a much larger electrolyzer
that could offer rate at a capacity of one hundred megawatts,
significantly more powerful than six megawatts. The article also mentions
a similar project in Cologne, Germany called Refine, but it's
r E f h y n E. It is a
ten megawatt electroalizer that's co located with an existing hydrogen
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refinery that's been using the steam reforming method to produce
hydrogen up to that point. Like the H two Future project,
this is a test, it's a pilot program. It's not
going to produce nearly as much hydrogen as the steam
reforming process at this level of power. It comes down
to about a hundred eighty thousand tons from the steam
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reform process versus hundred tons from electrolysis. But again, this technology,
if it works, could be scaled up and then you
would see more and more hydrogen being produced through electrolysis
and less through the steam reforming process. Now I focused
mainly on hydrogen production, but that's still just one piece
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of making a viable hydrogen economy. It's a super important one, obviously,
because if you don't have hydrogen, then the rest of
it doesn't make any sense at all. But even if
we were able to make plenty of hydrogen, let's say
that we've solved that problem. We've come up with an
electrolysis approach that uses green energy, it's incredibly efficient, and
now we're just churning out hydrogen like crazy. We still
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have some other challenges. For one thing, we've got designed
stuff to store the hydrogen and we have hydrogen tanks,
but we would need to build a lot of them
and to UH to test the various designs out, we
would have to design stuff to run on the hydrogen.
So what are our options here, Well, first, you could
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burn hydrogen fuel like gasoline. There are hydrogen internal combustion engines,
for example, and you would refuel them in a way
very similar that the way you refuel a gasoline powered engine.
So there are vehicles that use this UH in the
exact same way it cars use gas or petrol. Or
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you could use fuel cells, which in a way is
essentially that electrolysis process, but in reverse. So with a
fuel cell, hydrogen based fuel cell. I should add there
are different types of fuel cells, but we're specifically talking
about the hydrogen based ones. You on a very basic level,
you have hydrogen and a fuel cell on one side
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of the cell. You have oxygen on the other side
of the cell, and between these two gases you have
a special membrane with a catalyst on it, and the
hydrogen passes through the membrane, but the membrane requires the
hydrogen to ditch an electron. First. It says, all right,
you can come through, but your friend can't. So the
electrons like ah. But the electron really doesn't want to
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be with a bunch of other electrons. There are a
bunch of negative dancings, and we all know that similar
charges repel each other. So you have more and more
electrons building up. They do not want to be with
each other. You provide a pathway for those electrons to
follow a circuit. In other words, you make them do
work along this circuit, and eventually the electrons are allowed
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to rejoin the hydrogen nuclei, which again are just protons.
Remember that are on the other side, and that also
combines with the oxygen and you end up creating water
as a result. So you get electricity, water and heat.
That's the only thing the fuel cell gives off. Hydrogen.
Internal combustion engines aren't really that much different from standard
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combustion engines. They require some modifications, like you wouldn't want
to have spark plugs that have platinum tips, for example,
because that would react with the hydrogen. You want special
fuel injectors, special valves. You also would need a specialized
hydrogen storage system otherwise known as a hydrogen tank. The
combustion chamber would also need to be optimized to really
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harness the most energy out of combusting the hydrogen because
remember hydrogen, uh, the energy density is lower than that
of gasoline, so you need to really optimize the engine
to take advantage of all that power as much as
it can to make it as efficient as possible. Hydrogen
burns way more readily than other fuels, so it also
burns faster. The big advantage of this approach over fuel
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cells is that a lot of the work has already
been done, which means making vehicles that run on hydrogen
as a combustible fuel is relatively inexpensive. A lot of
the work has already been done in that field. But
burning hydrogen in a combustion chamber is not the same
thing as burning it with pure oxygen. It means combining
it with atmospheric air, and that also means that there's
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nitrogen in the air and you will eventually start producing
nitrogen oxides as a byproduct. Now, it's a much smaller
amount of nitrogen oxides than you would typically typically get
with a gasoline or diesel powered engine, but it still
means that the hydrogen combustion engine cars are not pollution free.
And because we need to look at the volumetric energy
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density of hydrogen. Those engines produce less power than a
comparable gasoline engine. Fuel cell vehicles get a bit more
omph out of a similar amount of hydrogen than the
hydrogen combustion engines do. Actually they get a lot more.
Fuel cells can be pretty efficient, like around the seventy
percentile range. They produce electricity, so you would pair these
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fuel cells with an electric motor, and in many ways,
fuel cell vehicles and electric vehicles are very similar. It's
just that electric vehicles run on batteries that have to
be recharged. Fuel cells rely on fuel. It's in the name,
so you have to refuel the fuel cell rather than
recharge it. Obviously, vehicles would just be one potential use
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for hydrogen. It could be used as a fuel in
tons of different applications. But there's still other problems that
we would have to solve. A big one is infrastructure.
It took decades to build out the infrastructure we've got
for fossil fuels, and that infrastructure has grown over the
course of more than a century. It's an estable, published
and entrenched system. In many ways, it's an investment. In
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other words, so we would have to build out something
similar for hydrogen if we were to depend upon that
more heavily as an energy storage method, so that would
be a really big price tag. Also, revisiting the production
issue for just a moment, there's the question of where
do you get the water. If you're relying on the
electrolysis method, preferably you would be using freshwater. It provides
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fewer problems than salt water. But in some areas, fresh
water is a very precious commodity that's in short supply,
so it would make very little sense to switch to
water and have it become even more scarce by dedicating
a good portion of it towards energy. There are projects
that are experimenting with using sea water as a source
for hydrogen, but seawater has lots of other stuff in
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it that can cause problems from this process, and it
may be small problems, like relatively small problems like corrosion
of the electrodes, which is, you know, it means you'd
have to replace the electrodes a much much more frequently
in the electoralizer. But there are other problems as well,
like the possibility that you would start producing chlorine gas,
which is deadly stuff. We've been talking about switching to
(32:09):
hydrogen as a primary energy storage solution for a really
long time. The term hydrogen economy, which describes a holistic
system of delivering energy through hydrogen, first popped on the
scene way back in nineteen seventy and I talked at
General Motors. A guy named Bernard Patrick John O'Meara Bachris,
or just John Bachris, came up with this phrase. Dr
(32:32):
Bachris was a chemistry professor and a proponent of hydrogen
for quite some time. This concept would see support come
and go over the years. Sometimes it would get a
little more focus, sometimes fade into the background. In addition
to the benefit that hydrogen would produce fewer pollutants than
fossil fuels, hydrogen economy would turn a country with water
(32:53):
access into a self sufficient nation from an energy standpoint,
which in turn would bolster now sational security because it
would mean the country wouldn't have to rely upon fossil
fuel resources that are produced in other countries. So in
the early two thousands, during the administration of George W. Bush,
the hydrogen economy got a lot of support, largely for
(33:14):
that reason it would remove our dependence upon foreign oil.
There are people who oppose the development of the hydrogen economy,
not saying it was a bad idea necessarily, but saying
it's going to end up being too costly and not
efficient enough to meet our needs, so it would at
best be distracting and at worst be completely wasteful and
and waste time and resources that could be spent on
(33:36):
different alternatives. And they may well have a point. It's
really hard to say right now, but hydrogen is likely
to be at least a component of alternate fuel and
energy solutions moving forward. It could end up being a
huge component if we get fusion to work, because fusion
would rely upon isotopes of hydrogen, and then you're talking
(33:58):
enormous energy density ease that more than dwarf the combustible
fuels we're talking about now. How big a part hydrogen
is going to play as a fuel remains to be seen.
It may require breakthroughs in both production and in how
we put it to use, and until we have a
storage and transportation infrastructure built out to support this, will
(34:18):
not be able to really rely upon it as extensively
as we do fossil fuels. So can we produce enough
hydrogen to meet our needs. I think the right answer
now is not yet, or maybe the answer is that's
just one part of the challenge, and we have to
solve a whole lot of problems to make hydrogen practical.
So let's not worry about too much. Let's try and
(34:38):
solve these problems first. Now, I do think it's worth pursuing.
I think fuel cells are super cool. I know some
people who love electric cars and that model, and they're
totally dismissive of fuel cells, But personally, I think both
models can work. And besides, even if we don't get
fuel cell vehicles rolled out on a wide scale, we
may put hydrogen to use in many other places. That
(35:00):
wraps up this episode. If you guys have suggestions for
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(35:22):
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(35:45):
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Wom
Get in touch with technology with tech Stuff from how
stuff works dot com. Hey there, and welcome to tech Stuff.
I'm your host, Jonathan Strickland. I'm an executive producer and
a love of all things tech. And on November I
ran across an article titled quote can we produce enough
(00:26):
green hydrogen to save the world? End? Quote? And I thought,
I haven't done an episode about hydrogen and the proposed
hydrogen economy for quite some time. It might be a
good sign to revisit this topic and remind everyone what
it's all about, because when it comes to conversations about
transitioning away from a dependence on fossil fuels, hydrogen is
(00:49):
frequently part of that conversation. Today, we're gonna explore why
that is, and whether we can in fact produce enough
of it responsibly in a green way to create a
true hydrogen economy. Spoiler alert, that's just one component of
a hydrogen economy. I'll talk a lot about that in
(01:10):
this episode. First, we gotta just lay some groundwork, right.
Hydrogen is the most abundant element in the universe. It's
what stars are made out of. According to the Los
Alamos National Laboratory, if you were to gather all the
atoms in the universe all the matters. So you've got
(01:31):
all the atoms in the universe all in one room, Well,
it would need to be a really big room, but
more than nine percent of all those atoms in that
room would be hydrogen. So at first you might think
that means we're lousy with the stuff here on Earth,
and we kind of are. But there's some other things
(01:52):
about hydrogen that makes that whole plentiful thing a little
more misleading when it comes to our day to day experience.
So first, pure hydrogen has a boiling point of minus
two hundred fifty two point nine degrees celsius. That's minus
four hundred twenty three point two degrees fahrenheit. That means
(02:14):
anything warmer than that extremely cold temperature will cause hydrogen
to boil off into a gas. To make hydrogen a liquid,
you would have to cool it down to thirty three kelvin.
Zero kelvin represents absolute zero. That's when you essentially have
no molecular movement at all. Absolute zero is colder than
(02:39):
empty space, which is somewhere around two point seven kelvin,
So thirty three kelvin is toasty in comparison, but it's
still colder than anything you're gonna find occurring naturally on
our planet. So on Earth, unpressurized pure hydrogen is going
to be in gas form, and this is a problem
(03:00):
because hydrogen is also the lightest element. The heavier elements
in Earth's atmosphere will push down and hydrogen will move
up higher and higher until it actually escapes Earth's gravity,
so pure hydrogen will float off into space. Capturing hydrogen
(03:20):
from the atmosphere isn't really a practical solution because of this.
So hydrogen also has a strong tendency to bond with
other elements, and that's really another very important thing. So
we can get to hydrogen here on Earth, but it's
bonded to other stuff Like two Hydrogen's can bond with
(03:41):
an oxygen atom and form water H two O. So
more on that in a bit as that's key to
the challenge of making a working hydrogen economy is figuring
out how to get hydrogen out of these compounds and
elements and things, not elements, but you know, mixtures. So
there are three common isotopes of hydrogen. The ordinary, boring
(04:06):
pure hydrogen that we tend to talk about is called protium,
and that consists of one proton that is orbited by
one electron. So the nucleus of pure hydrogen protium isotopes
is just a proton. Then you have deuterium that one
adds a neutron to the nucleus, so now you've got
(04:26):
one proton, one neutron in the nucleus orbited by one electron.
Then you have tritium that's a radioactive isotope and it
has a nucleus with one proton and two neutrons orbited
by a single electron. This stuff does occasionally form in
Earth's atmosphere when cosmic rays interact with the air, but
(04:48):
it has a pretty darn short half life. It's just
half life of twelve point three years. So when you
pair that with the fact that it's super light, so
little eventually flowed off into space. It's also very uncommon
for cosmic ray interactions. They aren't super commonplace. There's very
little chance for any significant amount of tritium to accumulate
(05:11):
in the atmosphere before it decays. Back in sixteen seventy one,
a philosopher and intellectual named Robert Boyle was doing some
exploratory research. He was using iron and dipping it into
different types of acid, and he saw that the reaction
in one of these combinations produced some bubbles some gas.
(05:32):
Many folks will call boil the the father of chemistry,
but at this point his observation mostly just consistent of
it's a gas man, you know anything more about it.
Almost a century later, Henry Cavendish, another philosopher and scientists,
identified hydrogen gas as a distinct element. The French chemist
(05:54):
Antoine la Vasier gave hydrogen its name. Now, the earliest
record I could find of a gas balloon that used
hydrogen as the lifting agent dates to seventeen eighty three
in Paris, but hydrogen was used for balloons and airships
for decades until really the Hidden Hindenburg disaster in nineteen
(06:16):
thirty seven that scared people quite a bit and stopped
a lot of people from using hydrogen as a lifting agent.
Hydrogen gas, by the way, is extremely flammable in the
presence of oxygen. So the Hindenburg caught fire as it
was docking with a mooring mast, and it was a
massive fire. It killed thirty six people, including one person
(06:37):
on the ground. There were a lot of people who
were on the Hendenberg who survived with some with severe injuries.
But still that's a pretty awful disaster. And it was
caught on film and there was a radio uh presenter
who was talking through the whole thing. If you've ever
heard the phrase, oh the humanity that comes from the
(06:58):
Hindenburg disaster, and it truly was a spectacular catastrophe that
tragically killed many people. Now, there are several hypotheses as
to what actually started this fire, but it was definitely
the hydrogen that provided the fuel for it to spread
so quickly and to cause such a disaster. So disasters
(07:19):
like the Hindenburg definitely raised huge warning flags with anything
associated with hydrogen and fuel in many people's minds, and
it persists to this day. There are people who say, well,
we don't want to invest in any sort of hydrogen
approach to energy storage because of the possibility of another
Hindenburg like disaster. Now, in the eighteen hundreds, a mixture
(07:44):
with hydrogen was used as gas for street lamps, so
it was actually being used as a form of fuel,
And in eighteen thirty nine Sir William Robert Grove would
conduct some experiments that led to the development of hydrogen
based fuel cells. So we'll talk more about fuel cells
in a little bit, But first, burning hydrogen gives off
(08:05):
water vapor and some other trace by products depending on
how you're burning. If you're burning it with pure oxygen,
you get water vapor. If you burn it in atmospheric conditions,
you'll get some small byproducts like various hydrogen oxides. It
all depends upon the composition of the air at that point,
but it does not produce carbon dioxide like burning fossil
(08:29):
fuels does. So it seems like hydrogen would be a
super awesome fuel source for us to go with if
we could be reasonably certain that the method we're using
would contain this reaction and not result in a in
a Hindenburg like disaster. But that's something we can totally do.
We can do that. I mean, cars are driving around
(08:50):
using gasoline as fuel, and gasoline is flammable, So why
don't we just switch to hydrogen. I mean, it's it's
the most plentiful stuff in the universe and it burns lean. Now, granted,
water vapor is a greenhouse gas, we have to accept this,
but water vapor also can incorporate into the water cycle
on Earth and out of all the greenhouse gases. We
(09:11):
actually understand water vapors roll in greenhouse gases the least,
But what's the hold up with hydrogen? While the big
one is that most of hydrogen on Earth is bound
together with other stuff like water that hydrogen and oxygen
or hydrocarbons like the hydrocarbon is an organic compound made
(09:32):
up of hydrogen and carbon. So if you have a
carbon atom and four hydrogen atoms, you would have methane.
To use pure hydrogen as fuel, you first have to
find a way to shake those hydrogen atoms loose from
those molecular bonds. So that means to produce hydrogen gas,
we first have to pour some energy into compounds that
(09:55):
have hydrogen in them to break those molecular bonds. You
gotta come up with a good way to do that
so that in the end of the day, the energy
stored in the hydrogen gas that you have harvested is
more than the amount of energy you used to get
the gas in the first place. Otherwise you have a
net loss and energy. If you pour more energy into
(10:16):
making the hydrogen gas, then you would get out of
consuming the hydrogen gas. You're losing energy. We call this
a bad thing. This is true for all fuels, by
the way. So if it cost us more energy to
get petroleum and to refine that petroleum into fuel, then
the petroleum fuel itself could store we would not be
(10:37):
using fossil fuels to begin with, because we would be
losing energy. We would instead say, why don't we use
whatever it is we are relying upon to get the
petroleum in the first place as our energy source. But
that's not the case. Now. We can measure the energy
content of various fuels by using an apparatus that allows
the fuel to burn under what's called standard conditions. Sanery
(11:00):
conditions means zero degrees celsius and one bar of atmospheric pressure.
One bar is close to one atmosphere at sea level,
it's actually a little less. A container of water with
a known starting temperature and a known mass will absorb
the heat that's released from this reaction, so you burn
whatever the fuel is. The heat gets captured by a
(11:22):
known quantity of water that's at a known starting temperature.
You measure the change in temperature of the water, and
that can give you the amount of energy that was
released by this process. Dividing that by the mass of
the fuel that you burned will give you the energy
content of the fuel typically expressed in jewels program or
(11:43):
or more typically mega jewels per kilogram. This is called
the specific energy of the fuel. Natural gas, which is
mostly composed of methane, has a specific energy of fifty
five mega jewels per kilogram. Get selene has a specific
energy of forty six mega jewels per kilogram, so it's
(12:05):
not as energy dense in this respect as natural gases.
Coal has a specific energy of twenty four mega jewels
per kilogram. Wood is all the way down to sixteen
mega jewels per kilograms. So what about hydrogen. Well, hydrogen
packs a wallop at one hundred forty two mega jewels
(12:27):
per kilogram. But hydrogen is a gas, so a kilogram
of hydrogen, the lightest element, is going to be an
enormous volume of gas. The mass is the same, a
kilogram is a kilogram, but the volume the amount of
space it takes up, is different. So this is deceptive.
(12:48):
We can't just talk about hydrogen the least massive element,
in terms of mass. It makes more sense from a
practical perspective to talk about in terms of volume, because
that's how we're going to handle it. How much energy
is stored in hydrogen for a given unit of volume,
I'll tell you in just a second, but first let's
take a quick break to thank our sponsor. Okay, So
(13:18):
for practical purposes of using energy storage, we should really
look at how much energy hydrogen has per unit of volume,
not unit of mass. This is truly what we mean
by energy density. So gasoline has an energy density of
thirty four point to mega jewels per leader. Natural gas
has an energy density of twenty two point to mega
(13:41):
jewels per leader. So we see the gasoline comes out
ahead when we look at it by volume, not by mass.
But what of hydrogen. Well, if you compress it so
that you can put it in hydrogen tanks, you're looking
at an energy density of about nine mega jules per leader.
So you need more leaders of hydrogen than of gasoline
(14:04):
in order to do the same amount of work when
you're burning it as fuel. In other words, because gasoline
has the energy density of thirty four point two mega
jewels per leader, hydrogen at nine, so that's an issue. Still,
hydrogen would burn clean compared to fossil fuels, so we
would just need to have enough hydrogen to compensate for this.
(14:27):
So how hard is it to get pure hydrogen from
various sources and how do we typically produce hydrogen gas? Well,
right now of hydrogen production comes from wood or fossil fuels,
and the most common process is called natural gas reforming
(14:48):
or steam methane reforming. This involves exposing methane gas, that
carbon with four hydrogen atoms connected to it, two very
high temperature steam this cause. This is a couple of
successive chemical reactions, and the end result is you get
hydrogen gas and carbon dioxide. This, as you might imagine,
(15:10):
is a problem because carbon dioxide is a greenhouse gas,
and so is methane actually, and this process creates one
and makes use of the other. So while you could
burn the hydrogen gas and not create any carbon dioxide,
the actual process of producing the hydrogen gas using this
(15:30):
method releases CEO two. So this is a good reminder
that when we talk about alternatives to fossil fuels, we
actually have to look at a very big picture, not
just what happens when we burn the alternative, but how
do we produce the alternative does that in turn create
more greenhouse gases? We have to look at the whole
(15:51):
chain to make sure we're minimizing the emission of greenhouse
gases and the release of potentially hazardous materials. You can
produce hydrogen safely this way, and even in an environmentally
friendly way. If you can capture the carbon dioxide, if
you have a method of carbon capture and you're able
to capture the CEO two that's being given off by
this reaction, then that might be a good way to
(16:14):
produce hydrogen. However, adding those components, like the carbon capture components,
increases the expense of producing the hydrogen. It's it's more
expensive to do it that way, and as you add
in the cost of producing the hydrogen, it means that
you're going to have to sell the hydrogen for higher
costs to recapture that and economics plays a very important
(16:36):
part of this proposed hydrogen economy. If it is not
cost efficient, it is a very hard sell. Money is
another part of the puzzle that we have to manage.
We have to be careful about that. So if it
comes out that fossil fuels are significantly cheaper to produce
and use than hydrogen, it's really hard to get momentum
(16:56):
to switch from fossil fuels to hydrogen. If fossil fuels
become scarce and therefore become more expensive, or the production
of hydrogen becomes cheaper, then that could provide the economic
incentive to make the switch. Or if the environmental impacts
of using fossil fuels, we're creating expenses that were out
of control. If it were a point where we said
(17:19):
we have to switch from fossil fuels because dealing with
the consequences of fossil fuel use is getting too expensive,
then we might see a switch as well, but it
would probably be a little late for that. There are
methods of producing hydrogen that don't rely on this approach.
So one of them is that you could take charcoal.
Charcoal is when you really break it down, mostly carbon
(17:42):
and water when you get down to it. So you
can put charcoal in a very high temperature reactor and
burn charcoal at a temperature between twelve hundred and fifteen
hundred degrees celsius. Doing so well, it will release gas
and that gas will separate out and then reform into
hydrogen carbon monoxide. So yeah, hydrogen, but carbon monoxide is
(18:05):
toxic to many animals, including us, and it also plays
a part in the formation of smog. So that's not great.
I guess the one positive thing I could say is
carbon monoxide itself is not a greenhouse gas on its own.
But the way that the article I first mentioned at
the top of this episode is really focusing on is
a third method to produce hydrogen. It is one that
(18:27):
only produces oxygen and hydrogen. Those are the only two byproducts.
It is the process of electrolysis of water, and electrolysis
refers to the separation of bonded elements and compounds through
the use of an electric current. So the idea is,
if you pass an electric current of sufficient strength through
certain materials, you can break the molecular bonds holding the
(18:50):
atoms of that material together. Pure water, as it turns out,
isn't great for this. You would need a very very
strong current because pure water is a poor conductor of electricity.
What you need are electrolytes in the water. And I'm
not talking about the stuff that plants crave. I'm talking
about the substance that when you put it in water,
(19:11):
creates an electrically conducting solution. It introduces ions. In other words,
but you need to make sure that whatever electrolyte you
include in the mixture doesn't electrolyze more easily than water does,
because otherwise, what will happen is you put the electric
current into the solution and the electrolytes will electrolyze, whereas
(19:32):
the water will not, and you won't release hydrogen until
you just have pure water again, and you're back to
where you started. So one of the ions that is
frequently used for electrolysis would be sulfate ions, because sulfate
doesn't electrolyze more easily than water does. So you've got
your water and you've got your electrolytes in it, and
(19:54):
then you put two electrodes, and one of them is
connected to the negative terminal of the battery. One of
them is connected to the positive terminal of a battery.
I'm just using a battery for this particular example. It
doesn't have to be a battery. So you've got your
negatively charged electrode that's called the cathode, and you've got
your positively charged electrode that's called the anode, and you
(20:15):
insert them in the water. Now, what will happen, assuming
you've done this correctly, is that hydrogen gas will bubble
up around the cathode, and oxygen will bubble up around
the anode. One of the traditional challenges associated with electrolysis
of water on a large scale is that the electro
catalysts catalysts are things that facilitate the reactions and chemical reactions.
(20:39):
They make chemical reactions happen more easily or with less
energy if you prefer. The electrode. Catalysts that we tend
to use for electrolysis also tend to be pretty rare
and expensive. Like one of the common ones is platinum,
but platinum is not easy to get. It is rare,
and so it's very costly, and that means the cost
(21:00):
of building out the system to produce hydrogen will get
driven up. And as I already mentioned, cost is one
of those factors we can't just ignore when it comes
to creating an alternative fossil fuels. So in some scientists
at the University of Houston announced the development of a
new electro catalyst made from a conductive nickel foam material
(21:22):
and a ferris metaphosphate. The relevant point here is that
this stuff costs less to make than if you were
to go out and get platinum. So this is a
push to make hydrogen production economically viable. And like I
said before, you have to take this big picture into account.
So that doesn't just include the materials you need to
(21:43):
perform electrolysis on water. You also have to ask where
is the electricity coming from? What is providing the electricity
I'm using for electrolysis. If you trace back the source
of your electricity and ultimately you're drawing electricity from a
coal firing power plant, then you haven't really solved any problems.
(22:03):
The pollution is still in the equation. It's just over
in the electricity production side as opposed to the direct
hydrogen production side. In fact, depending upon your approach, you
may be consuming more fuel and using up more stored
energy than you are producing by creating hydrogen if you
have a very inefficient system, and you'd be using a
(22:23):
process that releases greenhouse gases to boot, so that would
be a really bad idea. The article talked about green hydrogen,
and by that they meant using some sort of renewable
energy source to create the electricity, such as wind power
or solar power. That can be a step in the
right direction. If you're using wind power, solar power hydro
(22:44):
power or whatever, and you're generating more electricity then you
need to supply given area at a given time. Then
if you were to pair those facilities with an electric
electrolyzer facility, electrolysis facility, if you if you will, that
would make a of sense because electricity is a use it,
store it, or lose it commodity. At some point, you
(23:07):
might be producing more electricity than you need at that time,
and rather than lose it, you can put it to work.
You can take that excess electricity and put it to
work to produce hydrogen. So that article I mentioned at
the beginning of this episode goes into this concept in particular,
and it talks about a project in Len's Austria. That
project is called H two future H two, referring to
(23:30):
hydrogen gas. The goal is not just to create hydrogen
gas using electricity from renewable energy sources, but to use
the hydrogen as a fuel source for steel production. It
would be co located with a steel production plant, so
this would create green steel and steel production usually requires
burning a lot of coal and uh. It turns out
(23:53):
that steel and cement production together are responsible for about
twenty percent of all carbon diet side emissions in the world,
So if you could bring that down by creating a
hydrogen based steel production plant, you could drastically reduce the
amount of carbon dioxide that's being emitted into the atmosphere.
(24:14):
I'll talk more about these plans in just a second,
but first let's take another quick break to thank our sponsor.
The H two future project is a small scale test.
So this electrolyzer is paired with that steel plant, and
(24:35):
it's going to run at a capacity of six megawatts,
which is not particularly powerful in the grand scheme of things.
According to the article I was reading, which is over
on fizz dot org p h y s dot org,
this will result in the production of twelve cubic meters
of hydrogen per hour, and if the test proves promising,
(24:56):
the plant could invest in building a much larger electrolyzer
that could offer rate at a capacity of one hundred megawatts,
significantly more powerful than six megawatts. The article also mentions
a similar project in Cologne, Germany called Refine, but it's
r E f h y n E. It is a
ten megawatt electroalizer that's co located with an existing hydrogen
(25:20):
refinery that's been using the steam reforming method to produce
hydrogen up to that point. Like the H two Future project,
this is a test, it's a pilot program. It's not
going to produce nearly as much hydrogen as the steam
reforming process at this level of power. It comes down
to about a hundred eighty thousand tons from the steam
(25:40):
reform process versus hundred tons from electrolysis. But again, this technology,
if it works, could be scaled up and then you
would see more and more hydrogen being produced through electrolysis
and less through the steam reforming process. Now I focused
mainly on hydrogen production, but that's still just one piece
(26:01):
of making a viable hydrogen economy. It's a super important one, obviously,
because if you don't have hydrogen, then the rest of
it doesn't make any sense at all. But even if
we were able to make plenty of hydrogen, let's say
that we've solved that problem. We've come up with an
electrolysis approach that uses green energy, it's incredibly efficient, and
now we're just churning out hydrogen like crazy. We still
(26:22):
have some other challenges. For one thing, we've got designed
stuff to store the hydrogen and we have hydrogen tanks,
but we would need to build a lot of them
and to UH to test the various designs out, we
would have to design stuff to run on the hydrogen.
So what are our options here, Well, first, you could
(26:43):
burn hydrogen fuel like gasoline. There are hydrogen internal combustion engines,
for example, and you would refuel them in a way
very similar that the way you refuel a gasoline powered engine.
So there are vehicles that use this UH in the
exact same way it cars use gas or petrol. Or
(27:03):
you could use fuel cells, which in a way is
essentially that electrolysis process, but in reverse. So with a
fuel cell, hydrogen based fuel cell. I should add there
are different types of fuel cells, but we're specifically talking
about the hydrogen based ones. You on a very basic level,
you have hydrogen and a fuel cell on one side
(27:23):
of the cell. You have oxygen on the other side
of the cell, and between these two gases you have
a special membrane with a catalyst on it, and the
hydrogen passes through the membrane, but the membrane requires the
hydrogen to ditch an electron. First. It says, all right,
you can come through, but your friend can't. So the
electrons like ah. But the electron really doesn't want to
(27:46):
be with a bunch of other electrons. There are a
bunch of negative dancings, and we all know that similar
charges repel each other. So you have more and more
electrons building up. They do not want to be with
each other. You provide a pathway for those electrons to
follow a circuit. In other words, you make them do
work along this circuit, and eventually the electrons are allowed
(28:07):
to rejoin the hydrogen nuclei, which again are just protons.
Remember that are on the other side, and that also
combines with the oxygen and you end up creating water
as a result. So you get electricity, water and heat.
That's the only thing the fuel cell gives off. Hydrogen.
Internal combustion engines aren't really that much different from standard
(28:30):
combustion engines. They require some modifications, like you wouldn't want
to have spark plugs that have platinum tips, for example,
because that would react with the hydrogen. You want special
fuel injectors, special valves. You also would need a specialized
hydrogen storage system otherwise known as a hydrogen tank. The
combustion chamber would also need to be optimized to really
(28:51):
harness the most energy out of combusting the hydrogen because
remember hydrogen, uh, the energy density is lower than that
of gasoline, so you need to really optimize the engine
to take advantage of all that power as much as
it can to make it as efficient as possible. Hydrogen
burns way more readily than other fuels, so it also
burns faster. The big advantage of this approach over fuel
(29:15):
cells is that a lot of the work has already
been done, which means making vehicles that run on hydrogen
as a combustible fuel is relatively inexpensive. A lot of
the work has already been done in that field. But
burning hydrogen in a combustion chamber is not the same
thing as burning it with pure oxygen. It means combining
it with atmospheric air, and that also means that there's
(29:37):
nitrogen in the air and you will eventually start producing
nitrogen oxides as a byproduct. Now, it's a much smaller
amount of nitrogen oxides than you would typically typically get
with a gasoline or diesel powered engine, but it still
means that the hydrogen combustion engine cars are not pollution free.
And because we need to look at the volumetric energy
(29:59):
density of hydrogen. Those engines produce less power than a
comparable gasoline engine. Fuel cell vehicles get a bit more
omph out of a similar amount of hydrogen than the
hydrogen combustion engines do. Actually they get a lot more.
Fuel cells can be pretty efficient, like around the seventy
percentile range. They produce electricity, so you would pair these
(30:20):
fuel cells with an electric motor, and in many ways,
fuel cell vehicles and electric vehicles are very similar. It's
just that electric vehicles run on batteries that have to
be recharged. Fuel cells rely on fuel. It's in the name,
so you have to refuel the fuel cell rather than
recharge it. Obviously, vehicles would just be one potential use
(30:41):
for hydrogen. It could be used as a fuel in
tons of different applications. But there's still other problems that
we would have to solve. A big one is infrastructure.
It took decades to build out the infrastructure we've got
for fossil fuels, and that infrastructure has grown over the
course of more than a century. It's an estable, published
and entrenched system. In many ways, it's an investment. In
(31:04):
other words, so we would have to build out something
similar for hydrogen if we were to depend upon that
more heavily as an energy storage method, so that would
be a really big price tag. Also, revisiting the production
issue for just a moment, there's the question of where
do you get the water. If you're relying on the
electrolysis method, preferably you would be using freshwater. It provides
(31:25):
fewer problems than salt water. But in some areas, fresh
water is a very precious commodity that's in short supply,
so it would make very little sense to switch to
water and have it become even more scarce by dedicating
a good portion of it towards energy. There are projects
that are experimenting with using sea water as a source
for hydrogen, but seawater has lots of other stuff in
(31:48):
it that can cause problems from this process, and it
may be small problems, like relatively small problems like corrosion
of the electrodes, which is, you know, it means you'd
have to replace the electrodes a much much more frequently
in the electoralizer. But there are other problems as well,
like the possibility that you would start producing chlorine gas,
which is deadly stuff. We've been talking about switching to
(32:09):
hydrogen as a primary energy storage solution for a really
long time. The term hydrogen economy, which describes a holistic
system of delivering energy through hydrogen, first popped on the
scene way back in nineteen seventy and I talked at
General Motors. A guy named Bernard Patrick John O'Meara Bachris,
or just John Bachris, came up with this phrase. Dr
(32:32):
Bachris was a chemistry professor and a proponent of hydrogen
for quite some time. This concept would see support come
and go over the years. Sometimes it would get a
little more focus, sometimes fade into the background. In addition
to the benefit that hydrogen would produce fewer pollutants than
fossil fuels, hydrogen economy would turn a country with water
(32:53):
access into a self sufficient nation from an energy standpoint,
which in turn would bolster now sational security because it
would mean the country wouldn't have to rely upon fossil
fuel resources that are produced in other countries. So in
the early two thousands, during the administration of George W. Bush,
the hydrogen economy got a lot of support, largely for
(33:14):
that reason it would remove our dependence upon foreign oil.
There are people who oppose the development of the hydrogen economy,
not saying it was a bad idea necessarily, but saying
it's going to end up being too costly and not
efficient enough to meet our needs, so it would at
best be distracting and at worst be completely wasteful and
and waste time and resources that could be spent on
(33:36):
different alternatives. And they may well have a point. It's
really hard to say right now, but hydrogen is likely
to be at least a component of alternate fuel and
energy solutions moving forward. It could end up being a
huge component if we get fusion to work, because fusion
would rely upon isotopes of hydrogen, and then you're talking
(33:58):
enormous energy density ease that more than dwarf the combustible
fuels we're talking about now. How big a part hydrogen
is going to play as a fuel remains to be seen.
It may require breakthroughs in both production and in how
we put it to use, and until we have a
storage and transportation infrastructure built out to support this, will
(34:18):
not be able to really rely upon it as extensively
as we do fossil fuels. So can we produce enough
hydrogen to meet our needs. I think the right answer
now is not yet, or maybe the answer is that's
just one part of the challenge, and we have to
solve a whole lot of problems to make hydrogen practical.
So let's not worry about too much. Let's try and
(34:38):
solve these problems first. Now, I do think it's worth pursuing.
I think fuel cells are super cool. I know some
people who love electric cars and that model, and they're
totally dismissive of fuel cells, But personally, I think both
models can work. And besides, even if we don't get
fuel cell vehicles rolled out on a wide scale, we
may put hydrogen to use in many other places. That
(35:00):
wraps up this episode. If you guys have suggestions for
future episodes of tech Stuff, you can visit the tech
Stuff podcast dot com website. There you will find ways
to contact me on Facebook or Twitter, or you can
email me. The address is tech Stuff at how stuff
works dot com. You can go visit our store that's
over at t public dot com slash tech Stuff. Remember
every purchase you make goes to help the show, and
(35:22):
we greatly appreciate it. And don't forget we have been
nominated in the Science and Technology category of the I
Heart Radio Podcast Awards. Go on over to that website.
You can vote for us up to five times a day.
I would love to have the terrifying problem of going
up to accept an award in front of a bunch
of fancy people. And that's all for now. I'll talk
(35:45):
to you again really soon. For more on this and
thousands of other topics, visit how staff works dot com.
Wom
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Oz Woloshyn
Karah Preiss
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