Electric Vehicles, Dysprosium & China

There is an impending shortage of many rare raw materials used in the manufacture of hybrid and electric cars (Nishiyama 2007) (Cox 2008). For example, the rare earth element dysprosium is required to fabricate many of the advanced electric motors used in hybrid cars (Cox 2008). However, over 95% of the world's rare earth elements are mined in China (Haxel et al. 2005), and domestic Chinese consumption is expected to consume China's entire supply by 2012 (Cox 2008).

From the Wikipedia article on Electric Motors.

Just hold that thought for a minute and let me tell you how I got here.

I was thinking today that it could really make a lot of sense to replace the front wheel drive hardware on my four wheel drive pickup with a couple of electric motors. I mean you've got half a dozen U-joints, three sections of drive shafts, the front differential and the transfer case. That's a bunch of very expensive hardware. We have electric motors that can do the job now. Just look at all the hybrid vehicles and electric cars.

Didn't use to be that way. Used to be electric motors were big and heavy. But sometime in the last 30 years or so things changed. I think it's when they started using rare earth magnets. Niobium is one element that came to mind, so I decided to do a little checking, and that's when I came across the above quote. I've never heard of Dysprosium before, but the prices are going up, unlike Rhenium. [(see the price graph in the sidebar) Update November 2105. Rhenium price graph disappeared some years ago.]

Dysprosium 99% (FOB China in USD/Kg)

[Update November 2015. Replace with missing graph with one from a different source. This paragraph is no longer relevant: Metal Pages has price graphs for several forms of Dysprosium. This particular graph seems to have the most data points, which I suspect means it is the most actively traded, and therefor the most common form. But that's just supposition on my part.]

Anyway, back to electric wheels. Everyone is talking about the all-electric car and fuel cells and hydrogen and a lot of other pie-in-the-sky rot. But just replacing all the mechanical drive line components with an electric generator and some electric motors could give a you some big advantages. It's not like it hasn't been done: this is the way diesel locomotives work. They have one big diesel engine driving a generator which sends electric power to motors that in turn drive the wheels.

Cost could be a factor, but it can't be that bad, they are putting electric generators and motors in hybrid vehicles, and at least some people can afford to buy them. And then we would be eliminating the need for all that expensive mechanical driveline stuff (transmissions, I'm talking about you).

The first advantage is mechanical simplicity. Half of the structure of a car is used to hold the mechanical driveline components in alignment so they can function together. Eliminating the mechanical driveline means the structure of the car itself can be simpler. Another, at least for four-wheel and rear-wheel drive vehicles is more interior space. No more driveshaft hump, or allowance for the rear axle and differential. And it would make four-wheel drive much simpler. I see this as being a big an advance as hydraulic brakes.

There is another advantage specific to off-road vehicles and that is low speed torque. For climbing steep hills and rock crawling (where you need to carefully maneuver your vehicle over and around big obstacles) low speed is what you want, and with conventional mechanical drivetrains it can be very difficult to get. An all electric drive could be just what the doctor ordered.

Even if it is a good idea (and it is, it's mine after all), it won't happen overnight. There is too much invested in the industry that makes conventional driveline components. There are factories and equipment and people. I wouldn't be surpised if there were a million people worldwide somehow employed in making driveline components. And now it looks like we're going to have a shortage of something I had not even heard of fifteen minutes ago.

P.S. Rmb (from the chart) is renminbi or the Chinese yuan. The latest conversion rate from Google is:

1 Chinese yuan = 0.146477 U.S. dollars

so 700 Rmb (the high end of the chart) is roughly $100. Not as dear as Rhenium, but still more than pepperoni.

Update November 2015, replaced a graph, added a couple of notes, fixed a couple of typos, added a little polish.