PALO ALTO, California: Tesla CEO Elon Musk has predicted that the electric carmaker, which reported a record $5.5 billion in earnings in 2021, would see sales grow by over 50 percent in 2022.

However, the firm warned of slow growth due to supply chain issues that are hindering its manufacturing capacity.

Describing 2021 as "a breakthrough year for Tesla, and for electric vehicles, in general", Musk said, "While we battled, and everyone did, with supply chain challenges through the year, we managed to grow our volumes by nearly 90 percent last year."

Carmakers worldwide are grappling with a shortage of microchips, among other production and supply chain snarls, though Tesla has been faring better than most.

Tesla uses chips that are less scarce and quickly re-writes software, while competitors have responded to shortages by slowing production.

Tesla, which started in California, now has factories in China and Texas, with another under construction in Berlin. The four factories are expected to help Tesla dramatically expand its production in the face of rising new competition from established carmakers focusing on electric vehicles.

Looking ahead, Musk said he expected fully self-driving cars "will become the most important source of profitability for Tesla," as quoted by the BBC.

"The cars in the fleet essentially becoming self-driving via a software update might end up being the biggest increase in asset value of any asset class in history, we shall see," Musk added.

He has downplayed concerns that other firms might pose a threat, noting on Twitter that companies like GM have "some room for improvement".