Tesla Motors Inc. and Panasonic Corp. said Tuesday that they would begin producing cells for solar panels next summer at a sprawling factory opening in Buffalo, N.Y., expanding a relationship between the two technology firms. This article originally appeared at: http://www.latimes.com/business/autos/la-fi-hy-tesla-panasonic-20161227-story.html?utm_source=MIT+TR+Newsletters&utm_campaign=ca9509e208-The_Download.