I understand that Musk is planning on getting his Boring company to dig a plethora of tunnels under the Earth. These tunnels will host hyperloops that will be able to transmit packets of information across the country at phenomenal speeds.
The entire project will be powered by Solar City by day and an enormous battery Wall charged during the day and discharged at night.
If it works on Earth, then Musk will create an equivalent system when he builds in city on Mars.