
Scientists at Stanford develop water splitter that runs on ordinary AAA battery - happyscrappy
http://news.stanford.edu/news/2014/august/splitter-clean-fuel-082014.html
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nardi
I'm amazed at the ignorance in these comments.

First, _yes_ this is cool new science. No one imagined nickel would work as a
water-splitting electrocatalyst. This is very surprising, and awesome.

Second, the point of water-splitting is obviously _not power generation_. It's
power _storage_ , just like a battery, but with better transport and storage
characteristics.

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crististm
I don't know about ignorance, but basically, the energy you get from splitting
the water molecule (in the form of H2 and O2) is lower than the energy
consumed to make the split. For storage you will also have to deeply freeze
the gases unless you want to have huge tanks for storage

So what makes a hydrogen exposed freezing tank better suited for transport and
storage than a chemical battery?

~~~
cjensen
A car which runs on hydrogen can be refueled in a few minutes. Batteries need
an hour of charge or a battery swap which costs labor.

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seanflyon
A battery swap only costs labor if you do it manually. I don't see why you
would do that.

[http://www.youtube.com/watch?v=H5V0vL3nnHY](http://www.youtube.com/watch?v=H5V0vL3nnHY)

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kazinator
Presumably the low voltage saves energy. If a given number of electrons
produce the same quantity of H using two different methods, that means the
yield is related to current, and is the same for both methods, ampere for
ampere. And so the higher voltage method will have a bigger dissipation
(product of voltage and current).

Still, as a user, I don't care about voltage. How many kWh of energy does it
take to produce n grams of hydrogen with this method, and how does it compare
to existing methods.

Give me the highest relevant abstraction related to energy use.

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lutorm
... and not a single word about how the necessary electricity needed to make
this "zero emission fuel" is supposed to be produced.

Plus, all I know about hydrogen points to it not being anything close to "an
ideal fuel for powering vehicles, buildings and storing renewable energy". It
has very low density, requires cryogenic storage or very heavy pressure
vessels, migrates through materials, and is explosive when mixed with air.

~~~
nardi
This is like commenting on a battery tech article with, "Yes, but how are we
going to _charge_ all of those batteries?!" Or power grid technology, "Great,
but where is the electricity going to _come from_?!?!"

~~~
lutorm
Well, if they claimed that using batteries was "emissions free", I would
complain about that, too.

With hydrogen, the issue issue is that (at least to my understanding) if you
_have_ electricity, we already have a far more efficient solution: put the
electricity _directly_ into a battery and use it to power a motor. Going the
route over electrolysis->hydrogen storage->fuel cell imposes such efficiency
penalties that it would need extremely compelling other advantages to be
competitive, and I don't see them.

~~~
nardi
Hey, I like chemical batteries too, but they're not capacitors. You don't put
electricity into them. You drive an electrochemical reaction with them, which
is subject to its own inefficiencies, as well as wear and tear on the battery,
which isn't a problem with hydrogen fuel cells.

Hydrogen fuel cells also tend to be highly efficient.

~~~
lutorm
Sure. Are you saying the fuel cell cycle is actually more efficient than the
battery cycle?

The long-term performance question is interesting, though. Any idea how long
the time scale would have to be before the fuel cell wins?

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MichaelAO
I came across this video of Mike Strizki showing off his hydrogen setup during
my freshman year of college. I'll never forget it:
[https://www.youtube.com/watch?v=XcIbOkakkDQ](https://www.youtube.com/watch?v=XcIbOkakkDQ)

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ChaoticGood
Reminds me of Stanley Meyer's invention:
[http://youtu.be/Vd7QL1-NnlU](http://youtu.be/Vd7QL1-NnlU) A claim of hydrogen
obtained by water splitting fueled car. Very intriguing case of potential
pseudo science.

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partacus
How is this a story? Did someone at Stanford open up a grade 10 Chemistry
textbook?

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digikata
From the article: "Using nickel and iron, which are cheap materials, we were
able to make the electrocatalysts active enough to split water at room
temperature with a single 1.5-volt battery. This is the first time anyone has
used non-precious metal catalysts to split water at a voltage that low. It's
quite remarkable, because normally you need expensive metals, like platinum or
iridium, to achieve that voltage."

~~~
partacus
But it really isn't. The only thing of minor note here is room temperature vs
doing it at 60 deg C.

~~~
damoncali
At scale, that's a good bit of energy, I would assume. But I had the same
reaction as you did. "My 7th grade science class did that..."

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sirdogealot
This isn't news.

"The researchers also plan to develop a water splitter than runs on
electricity produced by solar energy."

Unfortunately that approach would be less efficient that simply transferring
the electrical energy to an electric motor.

Light > Electricity > Hydrogen > Electricity > Electric Motor

is longer than

Light > Electricity > Electric Motor

~~~
nardi
Ignorance. The news here isn't "we discovered electrolysis!" It's "we
developed a new, efficient, and cheap electrocatalyst!"

Did you do that when you were 9 too?

~~~
jacquesm
Actually, the kids chemistry book that I read as a 10 year old or so had a
very clear picture in it of one of the electrodes made of a guilder (dutch
coin at the time) and noted it worked better than other coins because of its
high nickel content.

That may have been coincidence but it certainly wasn't new knowledge to me
that Nickel works well as an electrode when splitting water in Hydrogen and
Oxygen.

I wished I'd kept my books from childhood and I'd be able to show you. It
wasn't a particular fancy set either, just a bunch of test tubes, some leads
to attach to a 4.5 V flat battery (I haven't seen those in ages either) and a
bunch of basic chemicals.

~~~
lutorm
We must have had a similar childhood! :-)

