California's KQED went out to Nevada for a tour of Tesla's huge Gigafactory 1, guided by Tesla co-founder and CTO JB Straubel.

Tesla's under-construction Gigafactory

Still under construction, when complete the factory will cover 5.8 million square feet — roughly the area of 100 football fields. But even with the Gigafactory stil years away from its projected 2020 completion date, Tesla's already put it to work. Tesla's home battery Powerwall and larger-scale Powerpack energy storage units are already being built on the site. In two years it will be churning out batteries for the hundreds of thousands of Tesla Model 3 reservations already placed — assembled at the Tesla Factory in Fremont, California, which the Gigafactory will be connected to via rail.

KQED went into the factory with Straubel, who explained how they're going to make what amounts to 35gWh worth of batteries in a year:

"So this is a pretty exciting room," Straubel says. It's filled with huge metal tanks, almost like an insanely-large industrial kitchen. "This is where we will actually mix the materials, the raw materials, we mix them into what's called a slurry."

The main pieces of the lithium-ion batteries, the anode and cathode, are baked by huge machines in yet another room.

"It's a little bit like a giant baking oven except it's a few hundred feet long," he says.

Batteries are right now the single biggest cost element in EVs. Tesla's not disclosing how much the batteries in their vehicles cost, but independent analysts have pegged the cost at "well over $10,000" per car. The Model 3 is set to start at $35,000, and Tesla CEO Elon Musk teased that he intends for the company to produce even less expensive EVs in the future, and the economies of scale the Gigafactory model will bring are projected to bring the cost of large scale lithium batteries down by 30% or more.

There's a lot more in KQED's visit to the factory, so go and give it a read — or listen.