The solar component is a stunt. Electricity is fungible. How about putting the solar plants where they work well (mountaintop? desert?) and the charging stations can just hook to the grid. Then they can get their electricity from any convenient source (local nuke plant for instance).
The argument about 'free solar' is almost an oxymoron. That electricity costs more per kwh than most any other source.
It is not a stunt. It is a direct counter to the anti-EV argument "Electricity is made from fossil fuels anyway, so by driving an EV you are just shifting the source of pollution to the power plant."
Tesla is attacking every single anti-EV argument in a very deliberate way and most of the attacks are strong successes.
It IS a stunt, in the sense that the solar feature is technically independent of the charging stations. The message is clear, but there is no necessary link between the solar elements and the place you go with your electric car to charge up. Placing them there is probably a worse decision that placing them optimally. That's makes it stunt.
And there is also a strong argument that the manufacturing and installation costs of solar farms has a long payback. They are a battery in that sense - energy invested in them slowly comes back out. PRobably petro-energy. So intially solar is a net negative in eco-impact. Same with wind.
The argument about 'free solar' is almost an oxymoron. That electricity costs more per kwh than most any other source.