Tesla CEO Elon Musk revealed the inside of his company’s massive Gigafactory to the media on Tuesday, showing an under-construction 1,000-acre structure in Sparks, Nevada. The facility is expected to reach completion in 2020 and the preview of the battery factory comes days ahead of the factory’s grand opening this Friday, where twelve lucky Model 3 buyers will get to tour the facilities and get an up-close look.

Media were also given first-hand looks at a prototype Tesla Model 3, which Musk says is “pencils down” when it comes to design. What the journalists saw today was what the final product would look like.

The Gigafactory’s primary function (outside of producing 500,000 cars per year before 2020) is to produce more lithium-ion batteries than had been produced in the entire world in 2013. So far, only about 1.9 million square feet have been built out, which is just 14 percent of the multi-story factory’s total footprint. In short — it’s going to be huge. Varied in its design for efficiency, certain parts of the factory will have different amounts of floor levels, ranging between 2 to 4.

Tesla has been rushing to meet demand for its upcoming Model 3, which has already received over 400,000 pre-orders. The Gigafactory is the answer that will help meet the company’s rapidly growing consumer base.

Gigafactory 1 may still have a chance to expand even further before Tesla moves forward with its future plans to build even more structures like it. For now, the goal is to finish the initial building plans by 2020.

The factory’s dedication to clean energy and its solar-powered promise goes far enough to make it impossible to use fuel in order to power the structure.

After the tour, Elon Musk and JB Straubel led a talk, followed by a Q&A with reporters. During the Q&A, Musk said that he saw the prices of the factory’s lithium ion batteries dropping in price below $100 kWh by the factory’s completion in 2020. Tesla is a leader in low-cost efficiency, and while Musk intends to keep that as part of his master plan for the company, advancing doesn’t come without a cost, and that cost will, eventually, be in the tens of billions. “Over time, this must necessarily be true,” Musk said. “Don’t quote me saying I plan to spend tens of billions right now because that would be incorrect.”

Photos via Tesla