https://cleantechnica.com/2024/08/23/see-through-windows-make-clean-electricity-from-raindrops/
A new super-smart, see-through window can generate clean electricity, keep interior spaces cool and defrost itself.
Those aren’t always a fit for everywhere. And getting energy from one place to another is an unsolved issue. Just because one option is cheaper than others doesn’t mean that particular option is the better choice. Diversity is very important.
Diversity is important, but it's still better to go after larger sources of energy first. There's just not much energy to be recovered from falling rain or waste from cars.
Make the cars waste less energy, or the transit system in general is much easier and will actually save money long term.