Elon Musk unveiled his master plan for Tesla Motors Inc, delivering a long-term vision that includes making an integrated solar and battery storage system and building a freight truck and a bus.

Musk delivered the long-awaited plan on the company's website partly to explain why the integration of Tesla and SolarCity Corp, of which he is also chairman, is necessary. He wants to use SolarCity, a rooftop solar panel installer, to generate electricity and charge an expanding range of Tesla models that address personal and public transport as well as cargo shipping.

"There are two other types of electric vehicles needed: heavy-duty trucks and high passenger-density urban transport," the Tesla chief executive officer said in the blog post, released on Wednesday. "Both are in the early stages of development and should be ready for unveiling next year."