Tesla’s Battery Proving Popular Early

In the first week of taking orders for its new line of storage batteries designed homes and businesses, Tesla’s latest product suite generated $800 million, according to some math from Bloomberg Business.

“It’s like crazy off-the-hook,” founder Elon Musk said of preorders on Wednesday during an earnings presentation.

The company notes it is already sold out of storage batteries until at least mid-2016.

“The sheer volume of demand here is just staggering,” Musk affirmed.

Musk’s new five-million-square-foot, $5 billion factory in Nevada is already looking too small to meet demand. It’s supposed to build all sorts of things for Tesla, but storage batteries alone could easily take up the whole factory, Musk says—which means an expansion isn’t just probable, it’s almost inevitable.

Profit isn’t high on the batteries, Tesla admits, but expects the margin to rise over time.