Electric car enthusiasts often laud automakers for making bold production volume forecasts for electric cars. After all, the more EVs there are the less oil the world will consume.
Even though forecasts vary, all of them agree electric car adoption will grow steadily in the coming decades eventually supplanting the combustion engine.
We often hear about concerns regarding lithium supply, as an essential element of electric car batteries, though most experts believe there is enough lithium on the earth to build at least 2 billion electric cars. And this isn’t including the lithium dissolved in sea-water, which could in theory at least be mined if necessary.
Little discussed, however, is the critical need for rare earth materials, which as its name implies is rare.
Demand for these elements, which occupy in 15 positions on the periodic table, is expect to exceed 40,000 tons annually within a few years. Chief among them is neodymium which is an essential component of electric motors and generators, providing its magnetism. Those motors also require the rare earths terbium and dysprosium which stabilize neodymium’s magnetic properties at high temperature. Another rare earth element, lanthanum, is required in the batteries.
The Toyota Prius, for example, with its relatively small motors and battery compared to all-electrics, uses 2.2 pounds of neodymium and 22 to 33 pounds of lanthanum per car. The Prius, says metals and commodity expert Jack Lifton, is “the biggest user of rare earths of any object in the world.”
“Rare earth availability is a serious problem as the EV market grows, though I’m not seeing much consternation about it yet,” said Mick Crane, the EV and hybrid director of Continental Automotive. “We could be trading dependence on one commodity, foreign oil, for another, rare earth metals.”
China is the world’s largest producer of rare earth materials, and since its own hybrid and electric car production capacity is increasing, will soon be the largest consumer. The country is already restricting exports. China is believed to have 95% of the earths’ supply of these element. The US imported 91% of its rare earth material from China between 2002 and 2008.
The looming shortage has Toyota scrambling for more sources including interest in locations in Canada and Vietnam. A promising rare earth location exists in California, which is slated to reopen in 2012.
Another significant future source is, of all places, Afghanistan which is among the world poorest countries. Afghanistan has recently been determined and reported to contain up to a trillion dollars in mineral resources which includes lithium as well. This report led to an internal Pentagon memo stating Afghanistan could turn out to be “the Saudi Arabia of lithium.”
“There is stunning potential here,” Gen. David H. Petraeus, commander of the United States Central Command, said of Afghanistan in an interview. “There are a lot of ifs, of course, but I think potentially it is hugely significant.”
Sources and further reading: (Reuters) (BNET) (NY Times)
+22
Jun 20th, 2010 (8:21 am)Rare earth production is a matter of price not availability. From California to Kings Valley, there are rare earth mines and lithium mines that have been shut down due to lower cost production in other countries. If the price goes up slightly, production becomes viable in many more locations than are in use today. The amount of rare earth elements in a BEV is still small, in an EREV, smaller still, so the price increases necessary to encourage increased production will be miniscule compared to the overall price of a car. But in the short term, there probably will be price gyrations as old mines come back and new mines are brought on line. It is just as well that the production of BEV’s will start slow and ramp up. But I still want at least 100,000 Volts built in 2012, as unlikely as that is.
+29
Jun 20th, 2010 (8:38 am)Also rare earth materials are more of a factor in NiMH batteries and electric motors with permanent magnets. Lithium ion batteries with AC induction motors pretty much eliminate the need for them.
p.s. Double check any claims you read of Lifton’s.
+8
Jun 20th, 2010 (8:38 am)I think recycling of these materials will be essential to produce many new products in the future. We should have means to put used electronics in a recycole bin just like we do for other recyclables. Everything from small batteries to speakers to electric can openers should be recycled with a convenient means to do it.
+8
Jun 20th, 2010 (8:44 am)There are trace amounts of rare earths in lithium batteries, but motors and generators can be made with just iron, copper, aluminum and some plastic for the insulation.
This along with electric cars polluting more than ICE cars is a red herring.
http://en.wikipedia.org/wiki/Red_herring_(idiom)
Jun 20th, 2010 (8:46 am)“Chief among them is neodymium which is an essential component of electric motors and generators, providing its magnetism” Something new to Google, or Bing. I know there is a number of closed Lithium mines. However I do not know much about about Neodymium.
+4
Jun 20th, 2010 (8:48 am)The rare element supply can be extended by recycling the components contain the rare elements. Automobiles and their components are extensively reused and recycled already.
At least in the US, lead-acid batteries are the most highly recycled component of commerce, with over 99% of spent batteries captured. Generally this recycle of car batteries is accomplished without a lot of pain as a result of regulatory action and retail pricing.
If these elements really become needed, the car components will be isolated for recycle, the same way that lead-acid batteries and catalytic converters are recycled today. If the costs continue to remain low due to oversupply from mining, then the components will not be recycled (unless forced by regulation.)
+5
Jun 20th, 2010 (8:53 am)Despite what the name implies, rare earths are not rare. They are not common, either. They range from about twice as common as lithium (lanthanum, neodymium) to about one twentieth (thulium, lutetium). Production facilities are not as simple, though, and there will probably be some supply problems.
+22
Jun 20th, 2010 (8:59 am)Crane also misses the obvious when he states that we would be trading one dependence for another. Relying on energy we need every day that is imported from Saudi Arabia, Venezuela, etc. is much worse than a one time requirement to use a small amount of rare earth material in the construction of a vehicle. A constant reliance on foreign oil is hugely destabilizing, but a smaller reliance on the production of rare earth that can shift due to pricing, availability or quality is a horse of another color. An embargo on oil shuts us down and crushes our economy, an embargo on rare earth means we have to restart mines here in North America that can’t compete on price normally. We import 12,000,000 barrels of oil a day, at $70 a barrel that is $840,000,000 we send to countries that tend not to like us too much. I need to break out my history books and study just how the opium trade between Britain and China developed and how it ended, because in a sick sort of way, our reliance on foreign oil is beginning to resemble the trade that was forced upon China.
+3
Jun 20th, 2010 (9:25 am)+1 to all those who pointed out that rare earths are not all that rare. What they are saying is that existing production does not have over capacity for anticipated future demand. Duh! Also GM-Delco developed a process many years ago called Magnaquench which gives equivalent magnetic properties to iron as neodymium. Before the bankruptcy this patent was sold to a Chinese manufacturer. The process now seems to be applied to or described as neodymium???
Anyhow, there are multiple solutions. Also the Volt uses induction motors (as does Tesla) not permanent magnet motors so this issue does not apply to the Volt. I think this has been a conscious decision on the part of GM to avoid buying large quantities of expensive neodymium
+5
Jun 20th, 2010 (9:28 am)The problem is the number of operating mines. China has the majority because their labor is so cheap…other mines in other countries can’t compete. If demand for rare earth metals goes through the roof, so will the price. That’s the great thing about capitalism. If there is $ to be made, there will be no problem raising capital to build/start new mines in other countries, including the United States. Any shortage will be short lived. I’m not worried.
Jun 20th, 2010 (9:33 am)Just a little OT, another promoter of AC induction motors for EVs is Raser http://www.rasertech.com/category/motors-and-drives/motors . They have sold a license to Hyundai. Hyundai has not been in the news much lately about their EV and hybrid cars but are working hard on them and will (I believe) have excellent products available soon.
+5
Jun 20th, 2010 (9:35 am)Another deception!
The AC induction motor which is the most popular and easiest to manufacture traction motor does not use neodymium. Neodymium is used to make super strong permanent magnets. Motors that use these magnets are not generally used as traction motors because they are so expensive to make. They are the most efficient and a little easiest to drive electrically though.
According Wikipedia, lanthanum is not so rare. This is another example of the automakers creating uncertainty and doubt to slow down the adoption of new technology. They are doing this to buy time in order to catch up. The trouble is the US car makers can no longer afford it. The practice of spending 5 years or more developing a car is now a luxury not a given. The Chinese automakers are going to put electric cars on the road before the US automakers even get their designs done.
+7
Jun 20th, 2010 (9:54 am)One more vote for rejecting the premise of this article. Lithium car batteries do not use 22-33 lbs of lanthanum, NiMH batteries do. Permanent magnet motors/generators may use some rare earth metals, but if these were not readily available, other motor/generator designs could be used.
Like Y2K, this is a hoax to make folks fear the future.
Go Volt, floor it GM.
+4
Jun 20th, 2010 (10:05 am)When the auto companies become convinced of the need for electric cars, a solution will be found.
This is the least of our problems.
Take Care,
TED
+1
Jun 20th, 2010 (10:06 am)If rare earth materials run out, don’t ask me to recycle my Altec Valencia speakers please.
Jun 20th, 2010 (10:12 am)Randy C says “Chinese will put e cars on the road before U.S. gets their design done”
Then why haven’t we seen Chinese ICE cars appearing on our roads? The Chinese have a big enough market at home for low cost autos of all types. It would be a less profitable use of resourses at this time to establish the export and sales infrastructure required for N.A.sales. IN the future this will change.
+4
Jun 20th, 2010 (10:13 am)I think the “Afghanistan as the Saudi Arabia of lithium” came from the same people who gave us the fairytales of WMD and the one-legged Zarqawi. It should be filed accordingly.
Lithium is no sense rare. It’s spread relatively evenly throughout the globe. As Ziv pointed out, the current price is a matter of production cost and technique. Also, unlike gasoline, you buy it once when you buy the car. You don’t fill up on Lithium every 300 miles. In the realm of toxicity, it ain’t and given its psychological effects, there’s a lot of people walking around who would perhaps benefit from some extra lithium exposure.
I hear all kinds of nonsense about lithium. I think it’s just knee-jerk conservative noise machine winding up thier audience to fear change of any kind. We must preserve the status quo, with our two wars near a gulf halfway around the world and poisoned gulf on our southern shores thanks to the “drill, baby, drill” crowd. How’s that working out for us?
+5
Jun 20th, 2010 (10:25 am)The Volt doesn’t use rare earth metals. Lithium batteries could be a flash in the pan, in 5 years we might be using some other chemistry, and eventually with capacitors improving as fast as they are, we will probably be using some kind of ultra capacitor. There’s a lot of lithium in Bolivia and Chile (friendly countries), and each Volt size battery pack only needs about 50 pounds or less of Lithium, and that will last 15 years, and then it will be recycled! That’s a lot better option than each Malibu that gets 25 mpg, at 15,000 miles a year for 15 years, that’s 9,000 gallons of gas. I’d say the Volt is a no brainer when it comes to geopolitics.
+2
Jun 20th, 2010 (10:26 am)Why do all of the backward countries with corrupt governments and religious nut cases who want to dismantle our country because of our success gets all of the important minerals that could make them an even greater economic success?
For me, it brings to mind the opening scene from ’2001: A Space Adyssey’ —- where the apes all stand around the monolith and throwing bones in the air.
+2
Jun 20th, 2010 (10:27 am)Shortage of material will increase price of material.
Since price of rare earth materials in the car is less than 1% of car’s cost, growth of price wouldn’t be noticeable.
But at the same time, high price of the material will allow more expensive mining methods, or will trigger research work – to find another solution. I see no problem.
Jun 20th, 2010 (10:29 am)Rats! Spell checker turned off! ‘Odyssey’.
Jun 20th, 2010 (10:32 am)Omnimoeish said:
That’s a lot better option than each Malibu that gets 25 mpg, at 15,000 miles a year for 15 years, that’s 9,000 gallons of gas. I’d say the Volt is a no brainer when it comes to geopolitics.
But what about my brother-in-law who supports his family working for an oil company, and hopes to retire on their stock? Don’t ask which one.
Jun 20th, 2010 (10:34 am)Necessity is the mother of invention.
As theses elements become less and less available, and we go to war with other nations over them, and killing each for them, meanwhile the ever expansive forward march of technology will develop methods and techniques to manufacture the necessary technologies without them.
Its only a matter of time.
+7
Jun 20th, 2010 (10:49 am)Let’s be quite clear: The Volt’s electric motor does not use magnets.
The Volt uses an induction electric motor. The Prius uses permanent magnet motors.
Induction motors generally have lower peak efficiency, but higher average efficiency across their entire power range. Induction motors are also lighter and cheaper to produce, but require much more complicated software algorithms to control.
EVs and EREVs generally use induction motors. Hybrids generally use permanent magnet motors.
More info here:
http://www.teslamotors.com/blog4/?p=45
+4
Jun 20th, 2010 (10:58 am)One thing I know about metals. They’re recyclable. Won’t be a problem for too long.
+2
Jun 20th, 2010 (11:05 am)Yes, +1.
Two nits:
1) Most if not all parallel hybrids use magnet motors, so induction isn’t the most popular for cars.
2) The terms “AC” and “DC” are somewhat meaningless for automobile traction motors. Induction and Perminent Magnet motor controllers both convert a DC power source into a quasi-AC voltage pulses that drive the motor. In fact, the hrdware that converts the DC to AC is almost identical for both types of motors – a bunch of high power FET switches connected to a microcontroller. The main difference is the firmware algorithms.
More info here:
http://www.teslamotors.com/blog4/?p=45
+2
Jun 20th, 2010 (11:06 am)Excellent point. You beat me to it. +1.
+3
Jun 20th, 2010 (11:23 am)There are today just two producing sources of neodymium; the Chinese mining complex ay Bayan Obo in western China and the aboveground tailings (residues from previous ore concentration) at Mountain Pass, Inyo County, California, site of America’s most extensively worked rare earth mine until it shut down in 1994. Mountain Pass is being reworked by Chevron Mining, the successor in interest to Molycorp.
Chevron sold their interest back to Molycorp LLC last year. Molycorp is restarting production at the Mountain Pass mine this year. As others point out, where there is demand and rising prices there will be new resources brought online. Rare earths will NOT be monopolized by a single source supplier.
http://www.magneticsmagazine.com/e-prints/Molycorp_summer09.html
+5
Jun 20th, 2010 (11:49 am)Looks like another premise run through the gm-volt.com gauntlet and subsequently shot to hell. Keep ‘em coming Lyle! Just a bit of a Father’s day skeet shooting for the readers in the know.
-1
Jun 20th, 2010 (12:08 pm)Another reason to favor natural gas. In the longer run lithium-air and like batteries decrease the need for rare earth elements. Moreover, it’s not so much that you depend on imports, it’s more a question of where the imports are coming from.
+2
Jun 20th, 2010 (12:17 pm)I have to concur that Rare Earth materials are potentially recyclable and it’s not quite equivalent to petroleum that gets burned and then takes geologic time to reproduce.
-9
Jun 20th, 2010 (12:21 pm)WOW!
I actually agree with you there. The use of AC induction is used on almost all EV’s. Rare earth materials for traction motors is little to none for those. As for moving dependence from one country/material to the other, you need to look at how foreign oil is consumed and must be “replenished” and Lithium is simply one purchase you can re-use/recharge.
But strangely but expectedly US car manufacturers are behind on EV deployment, as usual.
GO iMiEV and LEAF!!!
+2
Jun 20th, 2010 (12:32 pm)Lyle could have used this post to smite the FUD and deception … it is not like that needs much of research either. Sigh.
Jun 20th, 2010 (12:32 pm)[quote]Induction motors require much more complicated software algorithms to control.[/quote]
Huh? It’s a 3 phase AC motor? (or I misunderstand something?)
It is controlled by turning power on/off and that’s all.
Or by using frequency converter (standard device manufactured by any power electronics producer). Input: 4-20 mA or RS-485 or relay or anything controller can output. Any advanced enough controller has PID-regulator (no idea how this thing is called in english), that can be validated by tests. So, where is the difficulty?
+2
Jun 20th, 2010 (12:38 pm)Exactly.
Man.. the world sure has been ending for a long time now.
+1
Jun 20th, 2010 (12:41 pm)Behind who? Prius is not an EV. With the exception of up-price niche car Tesla, and some very small urban electrics, what manufacturers are currently deploying EVs and EREVs? When Volt and Leaf start rolling out within months of each other, they will be first to do so in significant volumes.
+1
Jun 20th, 2010 (12:43 pm)Gotta love Jon Stewart’s take on things.
http://vodpod.com/watch/3842093-ore-on-terror
+1
Jun 20th, 2010 (12:52 pm)No, it’s not at all that simple.
AC just means alternating current. Not all AC is the same.
An electric motor in a car has to run at many different frequencies, based on the speed you’re driving. It has to quickly accelerate or decelerate from one speed to another. It has to switch between running forward and backward. It has to run at maximum efficiency across huge load variations. And it has to do all this in a smooth seemless way.
So the motor controller (a.k.a. inverter) algorithms are way more complicated than a simple 60Hz power inverter that you can buy off the shelf.
More info here:
http://www.teslamotors.com/blog4/?p=45
Jun 20th, 2010 (12:58 pm)Randy didn’t say car motors, he did say traction motor. If you’re counting traction motors you’ve got to include every light rail and subway car plus the 1/3 of locomotives with induction motors. (Many locomotives still have series wound armature motors.)
+3
Jun 20th, 2010 (1:20 pm)Ha ha! It’s the only way the tired old power leaches (and holier than thous) cling to control.
+2
Jun 20th, 2010 (1:22 pm)By “inverter” you mean frequency converter I guess (maybe in our field we use little different words). Inverter transforms input DC to output AC (and also has frequency converter functions) – like Altivar 61 (Schnieder Electric). Anyway, inverter is needed in electric car with AC motor.
Altivar 61 can rotate engine forward and reverse, and operate at wide range of speeds.
I guess devil is hidden in details, and car motor behavior is much different from pump and fan’s one.
-10
Jun 20th, 2010 (1:25 pm)(click to show comment)
Jun 20th, 2010 (1:38 pm)Dave G said:
Let’s be quite clear: The Volt’s electric motor does not use magnets.
One of GM’s engineers at NY told me Volt has a permanent magnet motor. I was surprised, but that’s what he said.
-18
Jun 20th, 2010 (1:59 pm)(click to show comment)
Jun 20th, 2010 (2:11 pm)#34
It’s always nice to see your comments here. What a small world. Very cool. +1
+1
Jun 20th, 2010 (2:25 pm)Yes, exactly.
A car motor doesn’t just run at variable speeds. When you press the accelerator, it has to accelerate from one speed to another quickly, smoothly, and efficiently. When you put your foot on the brake, it has to decelerate quickly, and channel the regenerative braking power back into the battery. So at the same AC frequency (driving speed), the power can actually flow in either direction, and the power can vary a lot.
For an induction machine, this gets complex because you have to constantly model the induced magnetic field (the B field) on the rotor in all different types of driving conditions, and you have to do it on a little embedded micro-controller. For a permanent magnet motor, the magnetic field on the rotor is basically fixed by the magnet itself, so things are a lot easier.
Again, all this and more is spelled out here:
http://www.teslamotors.com/blog4/?p=45
Wally Rippel is more-or-less the grandfather of EVs. He did the motor designs for many EVs, including GM’s EV1 and Tesla Roadster. He’s since left Tesla, but they still post this excellent article.
By the way, the term “AC motor” is somewhat meaningless in cars. A “DC Brushless” motor actually uses alternating current and has a very similar inverter hardware design. So throwing the term “AC” in there is somewhat meaningless. These days, the real difference between car electric motors is whether or not they use magnets in the rotor. So a better way to differentiate is using the terms “Induction” and “Permanent Magnet”.
+3
Jun 20th, 2010 (2:58 pm)The iMiev uses a permanent magnet motor.
http://www.mitsubishi-motors.com/special/ev/4innovations/index.html
Prius also uses a PM motor, as noted in the article. This will almost certainly also include the plug-in model.
Anybody know about the LEAF?
There has been confusion since the beginning concerning the Volt’s specific motor arrangement. For one thing, how do you do regenerative braking with an induction motor? It’s theoretically possible with a sufficiently advanced controller, but you still have to supply energy to the field windings in order to get electricity from the motion of the car; this doesn’t sound terribly efficient.
Then there was the infamous Bob Lutz “secret transmission” comment, which lead to the revelation that the Volt contains not one traction motor but two. Still later, we found out that one of the motors was ‘optimized for regenerative braking.’ “Sport Mode” allows this motor to contribute power to help the induction motor drive the car, but is normally needed only as a regeneration ‘generator.’
Since NY, I’ve had a suspicion that the second, “regeneration” motor might well be a PM type which does not need a source of electricity for it’s field energy (allowing it to work instantly and efficiently as a generator). If so, it will require less rare earths than one designed to provide 100% of the motive power for the car. Volt would still have an advantage over cars with no induction motor, but would not be fully exempt from the potential vulnerability of rarer rare earth metals.
Lithium / Lanthanum is a non-issue as far as I am concerned, for reasons already well expressed above.
+2
Jun 20th, 2010 (3:04 pm)It’s the same old rehashed argument like the one that says that “peak lithium will replace peak oil.” It doesn’t take into account a number of facts:
a) production in rare earths can be increased, if necessay,
b) rare earths can be recycled, if necessary,
c) R & D and greater efficiencies will result in a future Volt that has a smaller motor and battery, thus requiring less materials,
d) the Volt’s motor & battery currently contains less amounts of rare earths than say the Prius.
The counter-argument that said materials can be recycled is ALWAYS an argument that is conveniently neglected by critics.
Keep in mind one general rule:
paradigm shift = skeptics + naysayers
George, Sudbury, Canada…go Volt!
Jun 20th, 2010 (3:10 pm)Wikipedia says it’s a synchronous motor, which usually implies magnets.
http://en.wikipedia.org/wiki/Nissan_Leaf
Jun 20th, 2010 (3:18 pm)Not quite. You have to supply voltage to the stator windings, not energy. When you apply voltage from the battery, the current can flow in either direction, depending on the timing of when the voltage pulses are applied.
The EV1 and Tesla Roadster use induction motors. Regenerative braking works great for those.
+1
Jun 20th, 2010 (3:28 pm)They told us the traction motor was AC induction back in 2007:
http://gm-volt.com/2007/09/14/clarification-chevy-volt-electric-motor-is-ac/
As for the generator, GM hasn’t said anything. In particular, we don’t know if the generator acts as a motor to start the gas engine, or if there’s a separate starter motor. We do know there is a separate 12-volt battery that’s large enough to jump-start other cars, so a starter motor is entirely possible. We also don’t know if the generator is induction or permanent magnet.
Jun 20th, 2010 (3:36 pm)Semantics. That’s what I meant. With no energy transmitted, there is no voltage. With permanent magnets, there would be no need to supply voltage to any motor winding to get electricity from mechanical force. The advantage in simplicity is paid for by reliance on the rare magnetic material.
This would be the first motor, the one which provides all the Volt’s motive power unless ‘Sport Mode’ is engaged.
Could it be possible that the Volt’s second motor is a small PM type which can supply electrical power to the stator winding of the AC induction motor for regeneration? That way, no power from the battery is needed.
Note: The 12V lead-acid battery is a “flooded cell” control battery. If it has power to jump start another car, that’s news to me. The generator on the engine is a separate unit from either of the two traction motors discussed above: the only way it would act as a motor is if it is used to start the generator direct drive fashion (an engineer in NY told me that this is the case).
Jun 20th, 2010 (3:50 pm)Again, with induction, when you apply voltage from the battery, current can flow in either direction. So this has nothing to do with electrical efficiency.
I’m not saying the generator is induction or PM, we just don’t know. 53 kW is small enough that PM may be more cost effective. I’m just saying there’s no efficiency problem using induction as a generator.
Jun 20th, 2010 (3:50 pm)Edit ran out. I meant:
“the only way it would act as a motor is if it is used to start the engine direct drive fashion”
Jun 20th, 2010 (3:53 pm)All of the big utility windmills use induction motors. Some tie directly to the line, and some have a back to back inverter so the rotor can operate at variable speed.
Jun 20th, 2010 (3:57 pm)Those of us without a real engineering education have to rely on a sometimes-fuzzy, imprecise “mental picture” which may not exactly fit the engineering reality. OK, so help me fill in the picture: What is the advantage of using magnetic material in a motor? Why would a motor of any size be built using rare earths? If it isn’t efficiency, what is the important factor?
So isn’t the line the source of power used to generate a magnetic field for the generator? (I didn’t know about the inverters, that’s interesting: so windmills don’t have to turn at an exact design speed to synchronize with the grid anymore?)
Jun 20th, 2010 (4:14 pm)There are many cases where you have voltage without energy. Remember:
power = voltage x current
energy = power x time
If there is no current, there is no power, and no energy. For example, a light switch in the “off” position has 110 volts across it, but there is no current, so there is no power associated with that voltage.
In the case of induction, when you apply voltage across the stator windings, current can flow in either direction, so it works equally well as a generator or a motor. You just need some voltage to start with.
This is not possible. The Volt’s generator may be PM, but we know the ICE isn’t connected to the wheels, so the generator must run at a different speed than the traction motor. This means the generator power must be converted to DC and then back to AC at a different frequency for the motor.
However, this doesn’t mean the power from the generator must pass through th battery. For example, in the diagram below, voltage from the battery is applied to both the generator and motor, but current can flow directly from the generator to the motor, bypassing the battery.
Jun 20th, 2010 (4:28 pm)PM motors have higher peak efficiency, so they are better if you typically run them at or near their maximum load.
PM motors also use much simpler algorithms in the motor controller (a.k.a. inverter). This means development costs are lower.
And if the motor isn’t that big, you don’t need to use that big of a magnet, so cost and handling aren’t big issues with smaller PM motors.
But as you scale up to higher power electric motors, induction starts looking better, especially if you don’t typically use it at or near peak load. The average efficiency of induction motors is usually better. So if you have a 110kW motor, but it typically only uses 25kW for highway speeds, then induction will probably be more efficient.
And here’s funny thing about induction, a bigger induction motor if often more efficient than a smaller one, with both motors at the same power output. That’s the exact opposite of gas engines, so it’s a bit of a mind-bender.
Jun 20th, 2010 (4:43 pm)According to Andrew Farah who is the Chevy Volt’s lead engineer:
“For Volt the answer is a bit more conventional. Yes, we have a 12v battery. It is not a typical automotive “flooded” lead, but a sealed “acid starved” type…. and it is capable of providing enough power to jump start another vehicle.”
http://gm-volt.com/2009/05/18/there-will-be-no-customer-access-to-high-voltage-on-the-chevy-volt-but-it-can-jump-start-another-car/
Huh? There is only 1 generator, and 1 traction motor. They are both together in the same housing, which was borrowed from the GM’s 2-mode hybrid.
Jun 20th, 2010 (4:57 pm)I have not, yet, read all the responses of this blog, so I’m almost sure somebody else has mentioned, that in Afghanistan, there is an enormous amount of lithium. Shortage of lithium is not a factor. In fact, this abundance will help make the cells cheaper.
Jun 20th, 2010 (5:07 pm)So what happened to all the troll comments? Do they disappear completely when they’re “voted off the island” now? Works for me, but isn’t that something new? I’ve gotten now to where I don’t even look at them if you have to click to view. I trust you guys enough that I just give them one more “-1″ to help to keep them there and move on down the line.
Jun 20th, 2010 (6:15 pm)Very simple explanation: They’re all “hung over” from yesterday.
Well explained, thanks.
I’ve heard both things. Yes, they’re definitely using the 2-mode housing. What isn’t clear (to me) is whether the generator turned by the engine is there, or somewhere else. It was explained to me in NY that ‘sport mode’ was the combination of two drive motors; one optimized for braking regeneration, the other the induction motor previously reported (the mode combines the second motor with the first, increasing power and energy use).
If the second drive motor is also the generator for the engine, it needs a means of un-clutching itself from the generator to be used as a motor (and a way of being clutched to the induction motor for sport mode). Frankly I do not find this plausible. What happens when ‘Sport Mode’ is engaged in CS mode, then? If there is only the induction motor and the generator, both clutches are engaged, and the engine (horrors!) is hard-clutched to the drive wheels.
+1
Jun 20th, 2010 (7:38 pm)Dave, in your diagram you have figure 2 as normal driving, which is the generator supplying all its power to the motor directly with no energy being diverted to the battery. I think that the generator feeding power exclusively to the motor will be rather rare. The generator has a capacity of 71 hp, and will use a few selected rpm’s for optimal power generation, but usually the generator will supply more energy than the motor requires for driving around town or driving on the highway at 65 mph. Is it possible that your figure 4 will be normal charge sustaining mode? I.e. the generator will be supplying more power to the motor, but a good deal to the battery as well? Perhaps approximately 30 hp/40 kW to the motor and 15 hp/20 kW to the battery while mildly accelerating and the reverse while cruising at a steady speed? The reason I ask is that I have hoped that the Volt’s charge sustaining mode could get considerably higher mpg if the generator is only working 60% of the time after you reach the 40 mile AER. I think that GM could surprise us when they announce the charge sustaining mpg, and surprise us in a positive way.
Jun 20th, 2010 (7:47 pm)The 2-mode housing connects the ICE crankshaft on one side, and the driveshaft on the other. I’m pretty sure that’s the same for both the Volt and the 2-mode hybrid. What isn’t clear is what exactly happens inside the housing.
Who explained this? Was it someone from GM?
I believe the 2-mode uses a similar clutching scheme. I’m not saying it works that way, just that it’s possible.
That’s the key! If Sport Mode doesn’t work with the ICE running, then we know that GM is using the 2 motors together for sport mode.
When this came up before, 2 or 3 other posters had heard sport mode always works, even with the ICE running, and 1 or 2 said it only works in all-electric mode.
And this is not just an engineering curiosity. For people who always use Sport Mode, this would be a significant issue.
Lyle, does “Sport Mode” work when the gas engine is running?
Jun 20th, 2010 (8:07 pm)Yes, it’s possible, but I think it’s more probable that the generator output will vary to match the demands of the electric motor as closely as possible. I think that’s why they have several fixed RPMs instead of just one or two. Also, a fixed RPM engine can generate a variable amount of power/torque depending on the load.
Using the battery isn’t free. There are efficiency losses in the electrical->chemical->electrical conversion. In addition, more charging/discharging tends to increase wear on the pack, which could shorten the battery life.
What’s more, if the ICE turns on and off constantly, this decreases efficiency. If the ICE turns on and off less frequently, but typically produces more power than the motor needs, then you’re apt to arrive home with the battery significantly charged, and that goes against the Volt’s primary concept, which is to run on electricity as much as possible.
Jun 20th, 2010 (8:16 pm)Ted id CORRECT! Engineers in this this country INCLUDING auto engineers tend to be quite resourceful and innovative.. The above posts make the point lithium ion batteries and induction motors do not require large amounts of not so “rare earth” materials. So auto engineers appear to be already in the groove. :+}
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Jun 20th, 2010 (8:29 pm)I thought I heard from Farrah that the battery tells the genset when to kick on and off–kick on when the battery has 30% charge left and kick off when the battery has more than 35%. Those number may not be correct.
Sounds to me there is a traction motor and an engine/generator and the two shafts are not physically connected in any way. I guess the generator could be used as a motor to start the engine.
Jun 20th, 2010 (8:31 pm)After the find in Afghanistan, I don’t think Lithium should be of any concern, at least for competition for pricing. Pakistan and the 9 “__________stans of former USSR probably are in like supply. These are untapped word resources.
Personally, anything is better than the addiction to Middle-East Oil.
-8
Jun 20th, 2010 (8:36 pm)No talk about fuel cells? Hydrogen? Hydrogen the most plentiful element.
Fuel cell electrics … that’s the future. Generate hydrogen from photocells.. wind.. hydro .. etc.
+4
Jun 20th, 2010 (8:36 pm)Very impressed with todays posts and discussions.. This is the reason I joined so one can learn about electric cars from many informed and reasoned opinions. Thank you!!! ;+}
Jun 20th, 2010 (9:57 pm)There are THREE motors used in the Volt, all inside the 2 Mode housing.. one motor is by itself and connected to the engine, it acts like the starter and the generator.. the other two motors are attached to the wheels (but no mechanical connection to the engine), one is optimized for regen braking and the other for normal operation.. in sport mode both motors work together with some losses in efficiency. All three motors are different, the regen one is the smallest.
Generator = 50hp continuous
Regen Traction= 50hp peak
Main Traction=100hp peak
Jun 20th, 2010 (10:14 pm)Eco_Turbo
Says
Jun 20th, 2010 (10:06 am)
If rare earth materials run out, don’t ask me to recycle my Altec Valencia speakers please.
Enjoy the good things in life, maybe when you are finished with them recycling might be an option
Jun 20th, 2010 (10:38 pm)Is this a guess or did GM announce it? GM has said 110KW max power for traction. Why have the extra expense of a 3rd motor and control for it, especially if it only adds 10kw for traction? Not to mention the added complexity. Seems that if they were using this approach, the main traction motor would have been downsized to @70kw.
Jun 20th, 2010 (10:45 pm)I believe in at least one of the videos sport mode was engaged while in CS mode and/or the GM rep in the car said it works in all modes.
Jun 20th, 2010 (10:51 pm)So, the two motors (regen traction and main traction) turn on the same shaft; on the output side of the two-mode housing, with the generator on the engine side. Mechanically simple, but electrically switchable according to function. If “Sport Mode” works in CS mode, this arrangement is confirmed.
This only leaves my original question: Does the regen traction motor use permanent magnets? Induction has been the announced solution since 2007, but Eco was told that at least one of the traction motors uses PM. Separating the two traction motors by function, with the smallest one using permanent magnets seems to be the best way, at this moment, to fit all the facts we think we know together.
By the way, I was told by the engineer who rode with us in the Volt that ‘Sport Mode’ uses both motors together for more power, but at the cost of more electricity.
Jun 20th, 2010 (10:58 pm)The regen motor, designed for that function, is less efficient than the induction motor when used as a source of motive power (I recall that being said). Might this have something to add to the equation?
Jun 20th, 2010 (11:59 pm)#68
I dunno, I don’t find occupying Afghanistan and/or any of the other “Stans” for the next 100 years to be much more appealing. Which is what it will take to get any appreciable amount of “resources” out of them, IMHO.
Jun 21st, 2010 (12:33 am)Yes, one Volt demo video shows a GM rep saying that he (personally) would stay in sport mode all of the time.
=D-Volt
Jun 21st, 2010 (2:25 am)off topic:
Have visited the Chevrolet dealers in the area. Information provided on Volt availability and pre-order vary from dealer to dealer. All of the GM people I have talked with are friendly and helpful. Seems odd that one dealer gives me a solid pre-ordering date. Another offers a vague date later in the year.
The dealerships are taking full names and address for their pre-order waiting list. From what I have seen. My guess is that about 12-15 people (total) are on the local Volt pre-order lists. This number should easily double by August 2010.
=D-Volt
+1
Jun 21st, 2010 (4:30 am)Well Team, I am super impressed with you ALL. I expected I would have to debunk this load of crap, and here all the work is already done for me.
So to recap; The Induction main traction motor(s) in the Volt do not use rare earths.
The battery is LiMN and does not use Lanthanum. (Neither does LiFePO4.)
The Volt DOES use Gasoline, and that is running out!
Now I wonder why Toyota started developing a second rate Lanthanum deposit in Vietnam all by themselves?
-4
Jun 21st, 2010 (6:16 am)Well that explains why the UK and the US are in Afghanistan then! Yep had heard about the news that the US survey think there’s a trillion dollars of minerals there. You can’t invest in a country with an unstable government – that’s why it’s really handy to replace the governments with ones that are friendly to US interests… and to help them draft (as the US has done to Iraq) all their laws forcing through privatisation of all aspects of their industries so the US companies can buy them cheap!
Jun 21st, 2010 (6:38 am)The old graph GM showed in 2009, in which the battery level fluctuated from approximately 30% up to 35% after the car reaching charge sustaining mode as the generator operated to both power the motor and replenish the battery, not to a full 80% but up to 35%, where it shut off. The charging portion of the cycle seemed to last 4 or 5 minutes and the charge depletion lasted 3 or 4 minutes, (which makes sense as 5% is about 0.8 kWh) but there definitely seemed to be a cycle to the charge/deplete on the graph. Battery life shouldn’t be affected by cycling from 30-35%, but there will be efficiency losses. The battery wouldn’t be fully recharged, simply charged to a slightly higher state, and I doubt that the engine coming on every 8-10 minutes would even be noticeable, unless you are listening for it to happen.
I remember people saying that they thought that the Volt would get 35-40 mpg in charge sustaining mode, my hope is that it will get 60 mpg at 65 mph and 55 mpg in town, unfortunately, I think even with regen braking, the Volts weight is going to keep its in town mpg down. But I think it will still beat a Prius.
Interesting times.
Jun 21st, 2010 (7:01 am)Wouldn’t it then also be less efficient at regen? My understand with AC induction motors is that the bigger, the more efficient. I think the advantage, if there are indeed 3 motors, must lie somewhere else. Perhaps Mrs. Catelan’s(?) comments about synching at certains outputs comes into play here.
Jun 21st, 2010 (7:25 am)For hybrids, the city MPG rating is usually higher than the highway rating. I suspect the Volt will follow this pattern as well.
As for weight, I’ve heard it doesn’t affect efficiency as much as you would think. Regenerative braking recovers most of the extra energy required to accelerate more weight. The main efficiency issue with more weight is a little more tire resistence, but that’s not a big factor. The real issue with extra weight is slower acceleration, so you need a larger electric motor and perhaps more powerful batteries to compensate. But as I said before, a larger induction electric motor is often more efficient than a smaller one, so that’s not an efficiency issue either.
In the end, I think the Volt’s MPG rating in CS mode is somewhat irrelavent. The more important figure is “Gallons Per Year”. With a typical driving pattern, assuming you only charge overnight:
Vehicle ……………… Gallons per year
Volt ………………………. 37
Prius …………………… 228
30 MPG car ………… 380
20 MPG car ………… 570
Jun 21st, 2010 (1:13 pm)Lithium is not rare at all. It is 6% of the Earth’s crust. It i sjust that up to now there has been relatively little demand for it.
The so-called “rare earths” are indeed much more rare. Bu they are NOT a Necessity. They are used in windings for some common designs of electric motors. However you can design a well known type of electric motor that needs no rare earths at all.
You can be certain that engineers at several electric motor manufacturers are busily doing so right now.
Jun 21st, 2010 (1:59 pm)I am constantly amazed at people who find Conspiracies everywhere. We didn’t know that Afghanistan had potential Lithium supplies to be mined.
For all the conventional BS about “War for Oil” the US has gotten little or no Iraqi Oil. Production has been down since Saddam Hussein was in power, and it hasn’t fully returned even yet. In the meantime substantial new deposits were discovered in Sunni areas but neither have been exploited and American enterprises were NOT rewarded with contracts to develop those sources in the future, either.
No one mentions that the industrialized World is ALREADY transitioning from Oil. Oil demand has been declining for almost a full decade. The world is amply supplied right now, and the Iraqi oil which is starting to flow will be a surplus and drag on the market.
I am amazed about the people who seemingly must find some reason to constantly worry and dream up End-of-the-World supply problems for whatever material. But then the present Energy Czar lost a bet back in the 1980s when he bet that 10 self-selected matériels would run out, and the opposition Mr. Simon bet the prices for all worldly be less in a decade signifying a plenitude of supply.
The gentleman even wagered that we would run out of Iron which is some 30% OF THE ENTIRE EARTH.
Jun 21st, 2010 (2:21 pm)Car production does not “use up” rare metals. It moves them from one place to another and refines them. We need to close all of our loops and finally, finally stop with this old “extract-consume-dispose” business model.
One word: *Recycle*
Jun 21st, 2010 (2:26 pm)Dave G,
My understanding is that much of the energy losses in an ICE engine are due to friction, so that a partially loaded ICE is pretty inefficient. For that reason, hyper-milers like to accelerate at full power, then let the car coast down to a low speed then “rinse and repeat”.
Wouldn’t that mean that the most efficient protocol for CS mode would be to run the ICE generator at full power as long as possible, rather than matching the ICE generator output to the needs of the electric motor?
Jun 21st, 2010 (3:11 pm)The problem is the batteries. In order to preserve their overall life, ICE generator output needs to come as close to load demand as possible; with only a trace going to/coming from the battery pack. If the batteries were more robust, ICE generator output could come much closer to the the average energy requirement over time, or the power level required to keep the Volt moving at constant highway speed (whichever is lowest); and be cycled on and off like an A/C compressor as needed (in City driving). This would allow a much smaller engine to be optimized for maximum efficiency over a much narrower range of rpms (closer to full power). This is forecast for Voltec version 3.0.
Jun 21st, 2010 (5:32 pm)Where did you come up with 6% of the Earth’s crust? According to Wikipedia it is more like 0.002%, which still isn’t all that rare.
+1
Jun 21st, 2010 (5:43 pm)Zachary,
I’m just not sure why a small motor is desirable. Running a small engine 50% of the time is no more efficient than running a 2x larger motor for 25% of the time. A small motor means substantial R&D, smaller production volumes, etc, etc. A larger off-the-shelf engine will be much cheaper and more reliable.
+1
Jun 21st, 2010 (6:45 pm)The 2012 model Volt is supposed to be FlexFuel. Since the initial Volt roll-out doesn’t include my area, and the 2012 model comes out next summer, I’ll wait for that.