Deliveries of the Semi were initially slated for 2019 -- this is the first delivery of a new vehicle for the company since the early 2020 launch of its Model Y crossover. Footage of the Semi played at the event showed the fully loaded big rig made a 500-mile journey from its Fremont plant to San Diego on one charge. 

Musk first revealed the Semi in 2017. At the time, he said a 300-mile range version of the big rig would cost $150k and a 500-mile version at $180k. Semi costs are above the average diesel-powered semitrailer truck cost of $120k. 

During Tesla's last earnings call, Musk projected 50,000 Semis would hit the highways by 2024. 

Bloomberg explained, "electrifying big commercial vehicles is crucial to transitioning to more sustainable transportation," adding trucks only account for 1% of the US vehicle fleet but produces a whopping 20% of all vehicle emissions. 

Musk thanked PepsiCo for being a "great partner" and welcomed two of the company's executives onstage to hand over the keycards in the first deliveries of the Semis. 

For faster charging, Musk said a new liquid-cooled cable capable of one-megawatt charging would be unveiled next year. He said the technology is coming to the supercharger network. 

Besides PepsiCo, Walmart Inc., Meijer Inc., and J.B. Hunt Transport Services Inc have been waiting for Semi deliveries since entering into non-binding reservation agreements in 2017.