It’s either a $5-billion gigawatt battery plant commissioned by Tesla Motors, the first of several the company plans to build to drive down the cost of its electric vehicle, and a source of 6,000 largely high tech jobs for the U.S. state of Nevada. Or it’s a very big pizza factory. That’s the cloak-and-dagger talk around the Reno Tahoe Industrial Center at 2641 Portofino Drive, after 50 earth movers were spotted preparing the ground for…something big. Greentech’s Eric Wesoff has the story, including a photo of the construction site.