Musk previously said that any merger would not impact Tesla's plans for the upcoming Model 3 EV and Gigafactory, which just officially opened. While the companies will soon be united, Tesla and SolarCity have worked closely together over the years, and the latter was founded by Musk's cousins, CEO Lyndon Rive and director Peter Rive. Musk is, of course, the chairman and largest shareholder of both firms.

SolarCity is set to release its earnings next week and said that it installed more photovoltaic panels than forecast last quarter (201 megawatts compared to 185 megawatts). However, it added that residential installations were down slightly. The acquisition is not yet final, as it includes a "go-shop" provision that will allow other potential buyers to submit offers for SolarCity until September 14th, 2016.