In a presentation by JB Straubel from September 2013, one of his slides showed Tesla Motors' projected growth in capacity at Fremont. It showed Capacity roughly doubling year over year. At the year 2019 mark, the expectation was for a 700,000 unit Capacity at that facility.
This is the part where I reiterate that Capacity, Production, and Sales are different things. Capacity is the number of vehicles that may be built at Fremont. Production is the actual number of vehicles built during a calendar year. Sales equals the number of vehicles delivered during a calendar year, and may include some that were built in the final quarter of the previous year, but reached Customers in the first quarter of the current year.
Tesla Motors' Fremont facility finished 2013 with a Capacity of 25,000 units; 2014 with a Capacity of 50,000 units; and aims to complete 2015 with a 100,000 unit Capacity. I expect that to grow to 200,000 unit Capacity during 2016, in preparation for Model ≡ Production in 2017.
I believe Tesla Motors will strive for Production to reach 70% of Capacity through 2017. Some quote Elon saying that Production in 2015 would be 50% over 2014. But he later clarified that as being for Model S alone, and that Model X production would be above and beyond that amount.
Model ≡ Production will begin at Fremont. Once its popularity demonstrates that there may be a two year waiting list, Tesla will move to establish their second factory in short order. Where? Idunno. Maybe one of the Southern states, like Texas or Mississippi. Maybe in Europe, perhaps Britain or the Netherlands.
No matter the location, it will likely have to be built anew, from the ground up. No one is going to give Tesla Motors a deal ever again. Ultimately, that's OK. They will be better off not having to reconfigure an existing facility to meet their needs. By building from the ground up, they may even consider that a second Gigafactory be co-located with the new factory.