Tesla aims to become more than an auto company. The electric-car maker wants to grow as a sustainable-energy company and increase its product offerings by getting into the solar business.

"The opportunity here is to have a highly innovative, sustainable-energy company that answers the whole energy question from power generation and storage to transport," Musk told reporters during a call shortly after the announcement.

"We are a sustainable-energy company, this is, broadly speaking, right in line with that. In order to solve the sustainable-energy problem you need generation, storage, and electric cars," he said.

Currently, if a Tesla customer wants to use solar energy to power their car, they have to first get the solar panels installed and then the battery pack and an at-home charger. But by integrating Solar City's business with Tesla's offerings, Musk envisions a one-stop shop where you can seamlessly get a solar solution.

"From a consumer standpoint, you walk into a Tesla store and in one place you can say, 'I'd like a great solar solution with an electric battery,' and you are done. In five minutes you are done. It's completely painless, easy, and it just works," Musk said during the call.

Musk also said that this move would enable both companies to design products that integrate seamlessly.

"This may seem counterintuitive to a lot of people, but I think it is so obvious that something should be done," Musk said. "Blindingly obvious."

"The world does not lack for auto companies — what the world lacks for is sustainable-energy companies, and electric cars are just one aspect of that," he said.

More:

Tesla Motors and SolarCity have always had a close link (Elon Musk is the chairman of both companies, and SolarCity was founded by two of his cousins -- the Wall Street Journal breaks down the crossover here) but now they may come under one roof. They already pair up on charging stations and power for off-grid homes, but Tesla is offering to acquire the energy company, saying it wants to provide its customers with access to the "most sustainable energy source available: the sun." Soon, you might be able to shop for solar panels, home batteries and an electric car all in one place.

The way Tesla sees it, linking up a solar panel, Powerwall battery and Model S/3/X electric vehicle means offering a more efficient way for customers to consumer energy that's vertically integrated. On a call with reporters, Elon Musk said the all-stock deal would end up with a price between $2.5 and $3 billion. He also said that it shouldn't impact plans for the Model 3 or Gigafactory going forward. According to Musk, "we're not an automotive company," pointing at the bigger issues it hopes to address around providing and using sustainable energy sources

Source:

https://engadget.com/2016/06/21/elon-musks-companies-may-team-up-tesla-offers-to-buy-solar-cit/

A few Reddit comments:

https://reddit.com/r/Futurology/comments/4p86v5/we_are_not_an_automotive_company_says_elon_musk/

Elon Musk Master Plan 2: https://techcrunch.com/gallery/dr-elon/

https://reddit.com/r/teslamotors/comments/4tc7fb/tesla_nososecret_master_plan_part_2_discussion/

https://reddit.com/r/technology/comments/4tue5x/elon_musk_reveals_tesla_master_plan_part_2/

https://reddit.com/r/Futurology/comments/4u183y/teslas_master_plan_part_deux_is_magnificent_and/

http://slate.com/blogs/future_tense/2016/07/21/tesla_s_master_plan_part_deux_is_magnificent_and_insane.html