Over the last 10 years, Tesla (TSLA 4.34%) stock has returned a jaw-dropping 2,900% to its long-term shareholders, making many millionaires -- and turning its largest shareholder, CEO Elon Musk, into a multibillionaire. And while few people will ever be lucky enough to get in on the ground floor of such a life-changing investment opportunity, Tesla's bull run looks far from over. New business verticals like lithium refining and artificial intelligence (AI) could eventually help power another long-term surge of growth and value creation, even if its automotive operations mature.

A license to print money?

Vertical integration can sometimes lead to new revenue streams for a company. Amazon.com is a perfect example. In the early 2000s, the e-commerce giant started what would become Amazon Web Services primarily to handle its internal data storage and processing needs. Now, that business has grown to provide most of its operating income. Tesla might pull off a similar feat with its investments in lithium refining.

Lithium is a key component of electronic vehicle (EV) batteries because of the energy-storage density it allows. But while lithium is fairly abundant in nature, it is difficult to refine, leading to high prices and short supply. Tesla aims to partially address these challenges with a new facility in Robstown, Texas, that Musk says will produce enough refined lithium to make batteries for 1 million EVs by 2025.

Musk has described lithium refining as a "license to print money" -- referring to its profit margins, which he likened to those found in the software industry. But while it's premature to expect Tesla's lithium business to be as important to it as cloud computing services became for Amazon, the venture will almost certainly reduce the EV makers' manufacturing costs by freeing it from a reliance on expensive imported lithium -- a competitive advantage that its EV rivals will struggle to replicate. The company could also sell its excess production to other manufacturers for extra revenue.

A $500 billion opportunity in artificial intelligence

Lithium refining isn't the only exciting non-automotive growth driver Tesla has up its sleeve. Artificial intelligence (AI) could also create boatloads of shareholder value. The company is tackling that opportunity through its Full Self-Driving program, which is unique because it relies on computer vision and neural networks, a type of machine learning designed to emulate the human brain.

Kids playing with money

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Tesla's self-driving software is already installed on at least 285,000 cars -- all of them generating vast amounts of user data that can be used to train and refine the system. The company aims to manage all this through a supercomputer called Dojo, which will feature in-house designed chips. And as with lithium refining, this project could help vertically integrate Tesla's operations while generating non-automotive revenue.

According to analysts at Morgan Stanley, Dojo could add a whopping $500 billion to Tesla's market cap by giving it an advantage in self-driving technology while also opening up other addressable markets like machine learning-related software and services. While these forecasts may prove somewhat grandiose, they do give investors an idea of what the new business could be capable of, even if it only achieves a fraction of its projected growth.

Don't forget about the core EV business

Tesla's investments in lithium refining and artificial intelligence are exciting because they open up the possibility for new revenue streams. But they could do even more for Tesla's EV business by reducing costs and enhancing its economic moat. Long-term Tesla investors have a lot to look forward to, and the stock remains a buy.