The messy business of rare-earth metals



The messy business of rare-earth metals

If you’ve followed our work over the past couple of years, especially during last year’s COP26 summit, you’ll know that we’re not afraid to draw attention to the volatile world of rare-earth metals. In fact, we’ve been banging the drum of discontent ever since we started AEM in 2017.

As a bit of background, most electric vehicles on our roads today use permanent magnet motors. This is because it’s a proven technology and was, until now, thought to be the most efficient means of powering a vehicle. The issue we have with permanent magnet motor technology is that each unit uses some 2kg of rare earth magnets.


There are grave costs to using rare earth metals

The mining of rare earth metals is, in short, damaging to the environment and harmful to those involved. For every single tonne of rare earth metals mined, it’s been reported that up to 1.4 tonnes of radioactive waste can also be produced. Mining 12 tonnes can generate enough acid-containing sewage water to fill an Olympic-sized swimming pool. If you compare rare earth mining to steel production, mining rare earths creates over 11 times more CO2 for every tonne of steel manufactured.

It’s not just the social and environmental issues of rare earth mining that need to be considered. As their name suggests, rare earth metals are only available in low quantities globally due to the highly complex process involved in their extraction. And scarcity, unsurprisingly, translates into a premium price point and a volatile trading market. Between March 2020 and March 2021, the cost of neodymium (a key element in electric motor magnets) increased by 240%. How can vehicle manufacturers scale their models with fluctuations as dramatic as that?


The only way to eliminate this problem is to eliminate the rare earths in motors

It’s hard, however, to criticise the practice when it seems that no viable alternative is available. That’s why we’ve spent several years developing our own semi-sinusoidal motor technology that does away with the rare earth magnets that limit an electric motor’s scope.

By removing the magnet in our design, AEM motors can spin twice as quickly as a permanent magnet motor. This makes it up to 12% more efficient and kinder to the environment. We’re also exchanging the copper windings for a compressed aluminium design. It means that our motor is made almost entirely out of steel and aluminium – both of which are easy to recycle through existing channels.

Thankfully, we’re starting to see the awareness around rare-earth mining grow. We’ve seen it not only amongst the major automotive manufacturers and their engineers, but with the rising number of environmentally conscious product buyers, too. We all have an appetite to go green, but it will be all in vain if we don’t remember our duty to do so sustainably.