The annual limit of ~8 GWh 18,650 cell production in Japan comes from several independent sources:
- Tesla made the following disclosure in the Q1'18 10-Q:
- "We expect Model S and Model X deliveries to be approximately 100,000 in total
in 2018, constrained by the total available supply of cells with the 18650 form factor used in those vehicles."
- The 8 GWh figure is a relatively straightforward estimate that comes from the owner-reported battery selection mix: about ~60% were 75D, ~40% 100D packs. If we apply this to the reported 99,475 Model S/X's delivered in 2018, we get: 99,475*0.60*75+99,475*0.40*100 = 8,455,375 kWh, or 8.4 GWh. Given that the survey is self-selecting and not statistically representative sample, I think it's probably a safe assumption that lower trim cars are under-reported vs. higher-trim cars - i.e. 75D sales were more than 60% and [P]100D sales were less than 40%. This would put the 2018 18,650 supply somewhere below 8.4 GWh. (I believe @ReflexFunds estimated a similar mix?)
So I believe all of this is a pretty robust basis to believe that the 18,650 cell supply from Panasonic was somewhere in the 8.0-8.5 GWh range in 2018, and that after about ~10 years of factory optimizations and a mature industrial process it probably doesn't have much space for low capex supply expansion.
- Finally, we also know that the supply limit is a capex constrained hard limit: this is how much the Japanese factories of Panasonic are able to manufacture per year. This was explained in the Q4'17 conference call by JB:
- "Romit Jitendra Shah - Nomura Instinet
Yes. Thank you. It sounds like from the letter that you could do more than 100,000 S and X in 2018, but you're constrained by the 18650s. And I'm just curious what would it take to see the 2170 cells in these vehicles?
Elon Reeve Musk - Tesla, Inc.
Yeah.
Jeffrey B. Straubel - Tesla, Inc.
Well, this is JB. It's something we've of course contemplated, but it's quite a large change to the architecture of the module and the battery pack overall. And while the 18650 supply is somewhat of a cap at about 100,000 units per year, even just a few months ago we didn't feel that expanding and making some long-term bets on expanding that supply with Panasonic in Japan was really the right risk. It's something we could consider, but right now we're pretty happy with that balance and it matches our other production capabilities and our other investments."
- I.e. in 2017 Tesla contemplated whether to expand the 18,650 supply, and decided against it.
If Tesla really wanted to expand volume, and their supplier agreement allowed, Samsung previously provided 18650 cells to Tesla for evaluation before being sourced with 2170s for the Australian Energy project. So, if Samsung had capacity, Fremont could make more than 8.5 GWh of S/X.
One of many articles (but this one makes me wonder if TE can use 18650 and 2170)
Exclusive: Tesla Takes Delivery Of 1.74 Million Samsung Battery Cells