Original URL: https://www.theregister.co.uk/2014/05/28/lithium/
Tesla's top secret gigafactories: Lithium to power world's vehicles? Let's do the sums
It's limited good news for Elon
Worstall on Wednesday As we all know, Tesla and SpaceX billionaire Elon Musk – with that forward-thinking "vision" the hyperloop hoper is known for – is touting around plans for a “gigafactory”.
The top-secret factory – for it seems there will only be one to begin with – will build lithium battery packs for Musk's own electro-vehicle firm, Tesla Motors. The spaceman insists the simple economics of mass manufacturing will make them 30 per cent cheaper and thus bring his electro cars down from eye-watering to merely expensive. He's also just recently gone on record as stating that there should be hundreds of such gigafactories over time, producing enough batteries to convert the world's entire vehicle fleet to electric power.
I don't think that's likely to happen myself. I think that fuel cells – for at least some part of both the electricity storage and vehicle fleets – are going to be the preferred technology. On the other hand, Musk is a great deal brighter and better at making money than I am, so what do I know*?
But we might also want to ask the question posed by commentard “bonkers” here, which is: If Musk is right, will there in fact be enough lithium to build all of these batteries?
Mmmm, veggies are a natural source of lithium (OK, to the tune of 0.00001 parts per million). They extract it from the Earth's crust, where - you guessed it - there is millions of billions of tonnes of the stuff.
The short answer is yes. Musk might be all sorts of things (he's certainly good at gaining government subsidies), but he's not a fool. He wouldn't have plumped for a technology he knew was impossible so therefore we must assume that it is possible. But that's, while good logic, not terribly appealing.
So, let us look at the numbers we have for lithium availability. From some work I did elsewhere:
Production: 37,000 tonnes.
Reserves: 13,000,000 tonnes.
Resources: 40,000,000 tonnes.
Total resources: 2,850,000 billion tonnes.
Those first three numbers come from the US Geological Survey, the usual source for these sorts of figures. That last number (and yes, that is millions of billions of tonnes) is my own calculation. We're pretty sure, to within a reasonable sort of margin, what the composition of the lithosphere is. We know, on average, how many parts per million of the top bit of the planet are copper, how many ppm iron and so on. We can take this “Clark number” and multiply it by the weight of said lithosphere and this will give us an idea of truly how much (at the very extreme) of an element is available to us.
It is absurd to think of mining all of that, sure. It would require that we strip-mined absolutely everything down to a depth of tens of kilometres. But just move the zero one place. We could do that with Australia, for example, which is about 10 per cent of the whole place. No one would really mind: at least, only Australians (so no one that really matters). Or, more believably, I'm not sure we'd even notice if someone strip-mined East Siberia. So, over the long term, there's at least hundreds of thousands of billions of tonnes of lithium available to us.
What this calculation is really saying is that there's a little bit of lithium in everything: your garden veg patch for example. And if we want it badly enough then we'll go and get it.
As to the other numbers, by production, we refer to the current annual global production; reserves are the working stocks of those mines/extraction plants currently in operation; and resources are where we know we could go to build a mine/extraction plant if we wanted to but we've not quite done the work to prove that we can yet. In the case of the latter, the emphasis is on proving to a specific legal and economic standard that it can be done (cost-effectively, within the laws governing the territory, et cetera).
Where does the Li lie?
There are two main sources at present and over the decades we tend to swing back and forth between them. Certain minerals (like spodumene) are rich in Li, so we mine them. Certain brines also have plenty of it. That brines are rich in Li gives us a clue that the oceans might be a possible source. And they might not be: it may not be economical at anything like current prices but it's certainly technically feasible to extract from the Atlantic.
Given the simply gigantic size of that last number, total resources, we're simply not going to run out of lithium for batteries. Most especially since we'd not need to have a constant stream of new material: once we've got some billions of car batteries then we'd obviously be reycling them anyway.
We might though think that resources aren't going to be enough for us to reach that nirvana: at which point let me tell you what the mining industry is really all about. You might think it's about digging out those reserves and resources, but it's not – not really. It's about working out new technologies which turn those "total resources" available into either resources or reserves. Another way to put this is that the mining industry creates minerals by inventing the technology that moves them from being metal containing dirt over into being ores.
One example of this is a little programme I am vaguely involved in on the German/Czech border. There's a local form of mica called zinnwaldite (after the German village where it was first found, Zinnwald, or “forest of tin”). The twin Czech village is Cinovec, or “place of tin”. (They were really inventive with place names around here.) Zinnwaldite is about 1.3 to 1.5 per cent Li. So could an economic process be found to extract this Li? The answer is yes, it could. It took about two years to work it out but it works... well sorta. If you've got this mica available to you (and there's plenty in local slag piles) then it's economic to process it. But it's not economically viable to go hard rock mining to dig it up to then process it.
So we could say that this particular attempt to move dirt over into ore isn't quite successful. But there are hundreds of attempts to do this with all the different possible resources every year. That's actually what one entire end of the mining industry attempts to do. And given the truly vast numbers of those total resources, we only need a small fraction of such attempts to succeed in order to provide us with the reserves and resources that we'll actually go on to use.
Underneath the pretty landscape of the German/Czech mining village of Zinnwald/Cinovec is rich tin-laden soil. Photo by Jens Jäpel, licensed under Creative Commons
Is there enough lithium to keep those gigafactories running? Sure, for there's really no shortage of any element on this planet of ours. The only real shortages we might have are in the human ingenuity to extract, economically, the elements that we already know are there. ®
*Apparently enough that Musk asked for my advice once on a technical point but it was only the once.