I wrote this yesterday. And as I wrote yesterday, and reflected on today, I started to realize the greatest reason Musk needs to own an inverter is because of the data network - not the few hundred million a year. This is the nature of a distributed power company. I'd guess Tesla/SolarCity have had very specific conversations on this topic with any vendors they use - lawyers write mean paragraphs regarding data rights. As TeslaSolar keeps growing, they're going to find more ways to sell their energy and related services. Having immediate access to distributed batfery storage via auto, home, commercial and Utility installations, plus solar generation to sell into active energy markets is worth a lot of money.