There's a lot of misunderstanding going around about Tesla's production lines.
Tesla is not adding a second production line right now. They are expanding and updating the current production line.
The best article to understand this dates back to last year May,
Tesla Motors Inc (TSLA) Envisions Selling Around 500K Units: Long Term :
"The main goal of the production team currently is to get production levels of 20K on a single shift across most processes (currently body assembly and finished assembly are still running on a 2 shift basis) and then ramp up to 40K units in 2 shifts. For the ramp up beyond 40K, the Tesla Motors Inc will require only $25-$50mn of additional capex to take the volumes to 50K units annually."
Let's dissect this a bit. So, Tesla can make 20k cars/year on a single shift on their production line. That's 400 cars/week (50 weeks/year). By adding a 2nd shift, they can ramp to 40k units/year or 800 cars/week. This is where they are currently. Then, if they add a capex expense to expand the line they can increase volumes to 50k cars/year or 1000 cars/week. This is what they're doing right now by shutting down the factory for two weeks.
In other words, Tesla is expanding their current production line to make it more efficient. How are they doing this? They are moving around things, and also adding more production capacity to certain parts of their line (ie., body and assembly lines). They're also updating the production line so that they can produce the Model S and Model X on the same line.
Some people think that Tesla is adding a second production line while keeping their original one. This is not the case. They only have one production line and they are just expanding it. It's still going to be one production line, just with an increased capacity of 1000 cars/week (although we can speculate that it's possible that the line might produce a bit more than that).
Now things get a bit complicated, since from how I understand things there are certain parts of the production line where it's a single line (ie., perhaps pressing), but there are certain parts where it's more than one line. So, you might be able to say that Tesla is adding another production line for certain parts of their production line (ie., body and assembly). But overall, it's still just one big fat production line.
If you notice, Simon Sproule (
Tesla Idles California Plant to Retool for Electric SUVs - Bloomberg) didn't talk about a "second" production line. Rather he talks about reconfiguring the production floor.
"Work to reconfigure the production floor at the facility in Fremont began yesterday and vehicle assembly will resume in two weeks, with a goal of boosting production by 25 percent, said Simon Sproule, a spokesman for the carmaker. The $100 million upgrade will add 25 robots and modify the factory’s body and general assembly lines, he said."
Also, Elon Musk in
Q2 2014 conference call doesn't refer to it as a "second" production line. Rather he says:
"So, it actually will actually be taking the factory – the Fremont factory down for roughly days or so in July to convert inline, which enables a substantial increase in our production capacity on the vehicle side, as well as a labor house reduction. So it’s just fundamentally more efficient process."
So, just because people on TMC say Tesla is adding a 2nd line doesn't make it true.
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It appears that Tesla is spending $100 million for the production line upgrade. Initially, the May 2013 Valuewalk article stated that it would cost $25-50 million to expand the production line to 50k cars/year (1000 cars/week). However, I think that amount was just for the Model S, meaning expanding the current line to make more Model S's. Tesla decided not just to expand the current line to make more Model S's but they've decided to update the line so that they can produce Model S and Model X on the same production line. I think this is where the additional $50+ million is going to.