
No rare earth metals in the Model S - kvprashant
http://www.teslamotors.com/forum/forums/no-rare-earth-metals-model-s
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001sky
_Tesla does not use rare earth metals in our battery or motor._

The HN Title [1] should be changed, as it is in effect editorializing beyond
the information provided, IMHO. As others have noted, there is no information
to suggest the statement is generally true, beyond these two sub-system
components.

[1] Currently: "No rare earth metals in the Model S"

~~~
dnautics
there are almost certainly rare earth metals in the speakers, for example,
although the mass would be relatively cheap compared to what you would need
for a motor.

Does the tesla have regenerative braking system, and I wonder if there are
rare earth metals there?

~~~
skriticos2
They have a 17" display in the dashboard. That certainly has some rare earths
in it combined with all the latest electronics.

Here is an article: [http://www.pbs.org/wgbh/nova/next/physics/rare-earth-
element...](http://www.pbs.org/wgbh/nova/next/physics/rare-earth-elements-in-
cell-phones/)

~~~
joezydeco
Good point. Almost every capacitive touchscreen uses a vapor-deposited coating
of indium tin oxide (ITO) as a transparent conductor.

Granted, it's a microscopic amount of indium, but still.

~~~
avmich
Indium isn't a rare earth element, is it?

~~~
001sky
Technically, its a (rare) precious metal.

[https://en.wikipedia.org/wiki/Precious_metal](https://en.wikipedia.org/wiki/Precious_metal)

~~~
Tuna-Fish
Which is a _completely_ different thing than a rare earth metal. (Which
incidentally are not rare or precious.)

To be fair, the group is badly named, but rare earth metals has a very precise
meaning -- if something is not one of the lanthanides, Scandium, or Yttrium,
it's not REE.

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fersho311
I wasn't sure what the implications of rare earth metals were, so I looked it
up. In sort, Rare metal extraction involves substantial pollution in the
mining, onsite processing, and refining phase. Mines create environmental
degradation through topsoil loss, poorly controlled tailings ponds that leach
into groundwater as well as lakes and rivers, roads slicing through habitat,
and the use of large amounts of energy to extract and process the materials
they uncover. Some rare earth metals require substantial processing, and that
provides a number of opportunities for pollution at every step of the way.
More here: [http://www.theguardian.com/commentisfree/2011/sep/26/rare-
ea...](http://www.theguardian.com/commentisfree/2011/sep/26/rare-earth-metals-
technology-boom)

~~~
steven2012
I think it's more to do with the fact that China has a monopoly on most rare
earth metals, and the supply can get constrained, like they did last year
against Japan.

~~~
dragonshed
Nitpick: China doesn't have a monopoly on rare earth metals, they just have
the least restrictive policies on mining them, and they won't export the raw
materials which forces companies to bring their processing operations into
china.

The US has _plenty_ of rare earths, they just always come up with thorium,
which regulators regard as a nuclear waste that must be disposed of at
exorbitant cost to the mine operators.

------
mchannon
While the motors may be REE-free, I wouldn't be so sure about the rest of the
vehicle.

Many models of LED's, lasers, displays, headlights, and power circuits use
trace but nonetheless essential amounts of rare earths. The motors and
actuators (power windows and locks, charge port and frunk poppers) and seat
heater relay might also contain them.

~~~
sologoub
Definitely doubt it's possible to have a completely REE-free modern electric
car.

The post name is definitely click-bait and should be clarified.

~~~
arthulia
I think it would be difficult to have a modern car that is REE-free.

------
hristov
I think the point the poster is trying to get across is that there are no more
rare earth metals in a Tesla model S than any other car of its class. Of
course there may be some small amount of rare earth metals in the speakers or
the electronics, but this is not an increase from any other car.

The issue of rare earth metals was used by some nay-sayers to incorrectly
argue that the Tesla model S is more environmentally damaging than equivalent
gasoline powered cars.

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jlgreco
Why is this notable, beyond possibly price associated with them? The only
issue with rare earth metals is that at various times the supply of them has
been politically shaky, though I think that is currently not the case? I'm not
really sure...

~~~
dnautics
currently not the case, as the US has spun up rare earth metal mines
(molycorp, e.g.) also the environmental concerns are less (not to say they are
nonexistent) when the US does it because we tend to care about the environment
more than china does, especially in california.

Also don't be decieved by the term, rare earth metals aren't really all that
rare. If anything their expense comes from the difficulty in extracting them
selectively from their ores - because rare earths are chemically similar (has
to do with the f electron shell being physically "buried" under the d and s
shells) they tend to ore together, and then become tricky to separate.

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zafka
It would be possible to build a more compact motor using NFeB magnets, but the
cost outweighs the slight weight/performance gain. It is also my understanding
that induction motor that Tesla uses is more efficient at regenerative
braking.

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chao-
The linked page describes this as something that "absolutely belongs up on the
Model S Facts page". Is there anything particularly negative about rare earth
metals aside from their potential scarcity?

 _Edit: fersho311 answers my question in the same minute I ask it. Thanks :)_

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phy6
The typical hipster that would complain about "rare earth" metals in a car
they'll never afford doesn't care about the rare earth in their iPhone or iPad
(which is one of the reasons they are made in China).

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diydsp
Fascinating! but I would add that not only DC motors use permanent magnets,
but also many synchronous motors, including stepper motors.

~~~
baddox
I actually wasn't aware that induction motors don't use permanent magnets. RC
model aircraft is a hobby of mine, and all I knew is that the commonly-used
brushless AC motors certainly use permanent magnets.

~~~
invaliddata
As a first order simplification, motors are all about pairs of magnetic fields
attracting / repelling each other. Often, one side of the pair is a permanent
magnet. If instead the magnetism is induced (implying no magnet involved, as
the other side must be switchable / controllable / varying, thus not a
permanent magnet), you have an induction motor.

At low power levels, permanent magnet motors (specifically brushless motors)
tend to have higher efficiency than induction motors, additionally, they don't
require complicated control systems to operate efficiently at varying speeds.
Thus you are unlikely to see an induction motor in an RC model anytime soon.

------
codex
No other electric car manufacturer can make this claim, as the rest use
permanent magnets in their motors despite the higher cost. Why, I don't know.

~~~
hristov
Because they want to have DC motors, while Tesla uses an AC motor. There are
various advantages disadvantages to both. DC motors require permanent magnets.
The AC motor on the other hand has the problem that the power coming out of
the battery is DC. So it has to be converted back to AC in order to be used in
an AC motor.

The Tesla has a large inverter that converts the DC to AC. Most other makers
choose to have a DC motor in order to remove the need for an inverter.

Some people joke that Tesla chose an AC motor, because that was the motor
invented by Nicola Tesla. But the AC motor has other advantages such as its
excellent torque curve. The latter ensures that the model s has no gearbox
while it features amazing acceleration at all speeds.

~~~
pkulak
Well, I know for a fact that the Leaf also uses an AC motor with an inverter.
It's documented all over the place. But, they have permanent magnets in
theirs, while Tesla apparently does not.

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achy
Does anyone know the relative merits of induction vs brushless with regards to
regenerative braking?

~~~
kineticfocus
There's a good answer in the comments section...
[http://www.teslamotors.com/blog/induction-versus-dc-
brushles...](http://www.teslamotors.com/blog/induction-versus-dc-brushless-
motors) ... search for 'regenerative'

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smackfu
This is just a forum post by Joe Random, not sure why it was posted here.

~~~
kvprashant
For the purpose of discussion.

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amalag
Lithium?

~~~
archangel_one
Not a rare earth element.

