NEW YORK (TheStreet) -- In conjunction with the $1.6 billion debt offering, Tesla Motors (TSLA) just announced, the company finally revealed plans for the Gigafactory. Much to no one's surprise, it's massive.

The carmaker notes that it expects to reach production unit rates of 500,000 cars per year by 2020 because of the Gigafactory. This is much faster than Morgan Stanley analyst Adam Jonas noted in his massive price target hike yesterday.

Tesla shares were higher in after-hours trading following the announcement, gaining 2.5% to $259.20.

Tesla also noted that due to the Gigafactory, battery costs would come down more than 30% by 2017, when the mass market, Gen III vehicle is slated to appear.

By 2020, not only is the Gigafactory expected to help produce 500,000 cars per year, but it's also going to be producing 35 gigawatts worth of cell production and 50 gigawatts worth of pack production.

It's going to be a huge factory, requiring anywhere between 500 and 1,000 acres, taking up 10 million square feet and housing up to 6,500 employees.

Though the final spot for the Gigafactory is yet to be determined, Tesla noted it is choosing between four states to get the battery packs to its Fremont, Calif. plant: Arizona, Texas, Nevada and New Mexico.

The company and its partners will invest between $4 and $5 billion into the plant by 2020, with $2 billion coming from Tesla alone. Tesla did not specify who would be partnering on the plant.

Here's what the Gigafactory will look like, according to Tesla's projections:

-Written by Chris Ciaccia in New York