Tesla Gigafactory in Sparks, Nevada. YouTube/Above Reno Tesla is considering building up to five Gigafactories, the company said in its fourth-quarter investor letter on Wednesday.

Tesla is currently building Gigafactory 1 in Sparks, Nevada that is slated to operate in full capacity in 2018. The Gigafactory is Tesla's massive battery cell production facility.

The automaker said it is currently finalizing locations for two additional Gigafactories, potentially three. That means Tesla could have five Gigafactories in total, counting its solar plant in Buffalo, New York that it acquired when it bought SolarCity in a deal worth $2.1 billion. The Buffalo plant will produce solar cells for Tesla's solar roof product.

Tesla CEO Elon Musk declined to comment further on the company's new Gigafactory plans during Telsa's fourth-quarter earnings call on Wednesday.

Musk said in November that the company was looking to build Gigafactory 2 somewhere in Europe and would decide on a location in 2017.

Tesla said in its earnings report that battery cell production started at Gigafactory 1 in January. Tesla is also installing Model 3 manufacturing equipment at Gigafactory 1.

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