I wonder about Musk. I don't think he's an idiot, otherwise SpaceX wouldn't have made it as far as it has so far. Yet he claims we need to move to sustainable energy which to me looks like just a big scam.
A part of me wonders if he is just making these statements in order to placate the woketards worried about their false god Gaia. They defunded the space program after Apollo because the woke said we shouldn't explore space until all the worthless eaters get fed. But that never ends, there will never be an end to the worthless eaters. By wrapping his mission in the cloak of the new woke religion he can stay off their radar.
Another thing I've noticed is there's some cross pollination between his various enterprises. For example, the prototype Starships all have Tesla batteries to supply power to their various systems. I also read that hyperloop is a joint Tesla/Spacex project. I have a few theories about this.
My main one is that the point of Tesla is to develop good EV tech for off-world mobility. IC engines won't work on the Moon or Mars, so having Tesla means he has the rover market cornered should he succeed in establishing off-world colonies. You could even argue that launching that Tesla Roadster on the maiden flight of Falcon Heavy was a test to see how the various systems of that car held up in the vacuum of space.
If he is serious about colonizing other worlds, he will probably want to set up decent transportation networks between different settlements. Hyperloop requires a near vacuum to work properly, so building those on other worlds with no atmosphere should be relatively easy.
Since it is doubtful that the government will let him launch equipment for building nuclear power plants in space, solar is likely his only option for powering these settlements, at least for the near future. In that light, pursuing solar power and building massive battery banks for them gives lots of valuable insight into setting up something similar off world. Getting that tech as good as he can, now, will make setting these power systems up in space easier.
I also think a lot of the living spaces on the Moon and Mars will likely be underground. This is where the Boring company comes in. supposedly their newest tunnel boring machine is roughly the same diameter as the Dragon spacecraft. I bet you could fit one in the cargo bay of an operational Starship quite easily. They also use all electric boring machines, just like Tesla cars. Set one up on the moon, and get it boring out living space for new colonists. They would be protected from radiation and temperature extremes. I think this would be quite valuable on the Moon, where a day lasts one whole Earth month.
Essentially, if humanity is gonna be able to live on the Moon and Mars, they will have to live without fossil fuels. By establishing himself as a leader in the industries working to remove dependence on fossil fuels he can solve a lot of the problems regarding how to run a civilization in space where fossil fuels don't work.