In Phoenix, Arizona, there are solar panels over the parking lots at since of the grocery stores. Makes a huge difference in survivability when you get back to the car.
(Without huge infrastructure dedicated to car welfare, Phoenix is uninhabitable.)
It's car optimized because the 110F weather makes it un-walkable in the first place. When I lived in a walkable city, I would prefer to walk 30 minutes than drive. When I lived in Phoenix, I did not want to spend more than 30 seconds outside in the summer.
You can always start small and over decades grow the area. After all that is how cities like Copenhagen and Amsterdam became bike friendly, not just a few years, but decades of work.
As a fellow European: we're prone to underestimating how uninhabitable bits of America are that nonetheless have people living in them. Those are port cities and therefore stable and temperate. You cannot green Arizona.
Just FYI there's a lot of ways to re-green a desert without actually being wasteful with water. There's some really impressive case studies out there. Shaping the land with berms and swales, building walls of trees to prevent water from being leached away by the wind, etc.
100F days are fine, cakewalks, even, especially with misters + shade. We had 70+ days of 110°F two years ago, and over 20 days 115°F+. They are not the same. Those days are unbearable nightmare fuel, and worse, they turn into insanely miserable nights where the low temperature rarely dips below 95°. It is absolutely awful, dry or not.
Phoenix as well as other similar places (such as Las Vegas where I live part of the year) have an outsized benefit from installing solar compared to normal places. We basically never have to deal with rain or clouds. Installing solar here is a total no-brainer.
(Without huge infrastructure dedicated to car welfare, Phoenix is uninhabitable.)