In the latest version of Tesla's master plan Musk paints a picture of a renewable energy enterprise, with goals such as creating solar roofs that are seamlessly integrated with battery storage, an expanded vehicle product line that includes heavy duty trucks and large passenger transport vehicles, working toward "true self-driving" that is 10-times safer than manual driving, and enabling your car to make money for you when you aren't using it.
Creating the "solar-roof-with-battery product" is the first piece of the plan. Musk envisions a system that would turn individuals (or perhaps more accurately, homeowners) into their own utilities. This is why Musk wants Tesla to fully acquire SolarCity.
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