Lets assume that Tesla is making so much lithium packs that they have to give them away.
The problem is that they still cost, partly that they have to over-spec the capacity (at 70%) in order to make them last more than a few years, the other is that the packs will wear out on a continual basis (depending how hard they were used by the car owners) and so not only do they have a lot of active management (not just monitoring and maintenance) as somebody will be bring new and removing old packs all the time, for a very large installation that could be weekly deliveries.
Then they have to deal with the old packs, and they cannot just chuck them in landfill these days, the cost of scrapping them is large.
So the investment case for lithium is a short-term thing, yes they work and yes there will be a lot of supply, but grid customers will be looking at very long-term installations.
I don't have much figures for the Tesla storage but, when Musk announced Australia could have a 129MWh plant for free if they failed to deliver on time, he said it would cost the group $50m. A Tesla 80MWh farm completed in the USA is estimated to cost $100m. That's a lot of money for something that is so plentiful to be free! Meanwhile, Tesla upped the price of its Powerwall units recently, so its obvious the cheapness of lithium packs isn't so significant a factor in the overall cost of supplying these installations.
One investment case for many different types of storage tech can be seen in Lazards "levelised cost of storage analysis" report
(page 9 of this pdf if you want to skip to the action)McKinsey report
(much easier to read) says:
For large-scale firming of wind power, our model shows that flow cells can be more economic than lithium-ion cells for all but the shortest periods (less than an hour) and are projected to continue to lead on cost through 2020.
So these all think lithium is getting cheaper, but the rate of drop is now a lot slower, whereas flow batteries, being new and not having the scale to date, will drop a lot faster. RedT says that their current customers are getting 24 cents per kWh
, which is equivalent to lithium batteries that cost 22c per kWh, though if lithium batteries drop to $100 per kWh then this will drop to 11c/kWh (ie 11c is the cost over its lifetime)
Ultimately, the investment case for anything is less about the technology, and more about the ability to sell. This is why I'm into RedT as they have that finance thing and the German op, it doesn't matter so much if lithium sells more - all I'd care about is if RedT can sell enough.If they can make money then I see the share price going up significantly from 7p (fingers crossed). There's so much demand for storage coming that there is space for many different providers. In 20 years these may consolidate or go out of business, but there's along way to go before then (or Google's "goodenough" glass storage (ie sodium-ion) tech might make lithium obsolete!). Right now the challenge is getting started - and again RedT is just out of that phase (compared to other companies making storage products such as compressed air, hydrogen or hot asphalt storage)
RedT produced an investment case from Apr 18
, but obviously it's from them so not as impartial as elsewhere, but still interesting.