So it was Panasonic that was straight up lying? At least this puts down the benchmark to measure Q2. 6GWh of cells means 500MWh of Tesla Energy plus 73333 Long Range Model 3's. Substantially less and cell supply isn't the bottleneck anymore.
So, as somebody who was also trying to make sense of this earlier (and got it wrong), in light of Elon's recent tweet I went and looked at what Panasonic said:
(emphasis mine)“Panasonic established a battery production capacity of 35GWh in Tesla’s Gigafactory 1 by the end of March 2019 in line with growing demand. Watching the demand situation, Panasonic will study additional investments over 35GWh in collaboration with Tesla,”
So it doesn't appear there's any lying going on. When taken at face value, what Panasonic, Tesla , and Elon are all saying jive (Occam's Razor, and all that).
A manufacturing line for physical objects (be they batteries or doorknobs), is still a largely mechanical logistics effort. For something that needs to produce millions of items a day at high speed, this isn't just a matter of installing the machines and turning them on.
My father worked in a plant that produced glassware.... 100's of thousands of bottles/jars a day. Getting a manufacturing line up and running was an immense tuning effort, and peak production took some time to reach the capacity limits of the machinery. Things like:
- Conveyor system alignment issues causing product to not flow correctly
- Speed matching between conveyors and machinery
- Annealing temps of ovens inconsistent
- Temperature/humidity variations changing the cooling rate of the glassware
- Transfer equipment alignment/tuning
- Mold imperfections/refinement
- Travel angles of the conveyors
- Guide and barrier adjustment
- Sensor/gate adjustment
- Air pressure variances
- etc...
And this process is somewhat iterative as speeds increase. What might work at 100 items a minute might not work at 125 items/min... all it takes is one conveyance mechanism to be a fraction of a percent slower than the one preceding it, and product begins bunching up or you have to throttle the entire line.
And there are dependencies: increasing the speeds requires greater air-pressure to operate the molds faster but which increases closing force which induces stress in the glass which requires a different annealing temp profile.
Now while certainly batteries and bottles are vastly different, and certainly the GF has highly automated lines, it still doesn't mean there isn't a big effort to tune this to reach theoretical capacity. It just may be that some of it is done in a terminal session rather than with shims and a wrench. But there are still also going to be a lot of physical adjustments too.
I can imagine some of the stuff that you might have to tune on a battery line:
- Conveyor rates
- Transfer alignments
- Casing clamping force
- Material insertion alignment
- Drying oven temp profile adjustment
- Cap attachment alignment/tuning
- Electrolyte filling/tuning
- Lead attachment
- etc...
There are a myriad of logistics involved... and a whole slew of interdependencies we probably can't imagine. So what works for 24 GWh/yr rate may not work for 28. And that may not work for 32... and that for 35. And this is all in addition to the materials issues that @sparcs mentioned.
So, if this is all going to go on for the next period of time, and they have no significant indicator there's a showstopper, it would seem to make sense that now that they've reached there initial goal (35GWh of capacity installed), they stop and evaluate next steps while the production ramps up.