I remember seeing a similar system in the old town of Palma de Mallorca. Seemed like a good idea at the time even for the cost (23 million euros), but last I saw, they were out of order due to maintenance issues and people putting things down there that they shouldn't like old umbrellas.
Edit: yeah, [2] for instance, from 2017 or something.
[1]: https://www.untappedcities.com/inside-roosevelt-islands-futu...
[2]: https://news.ycombinator.com/item?id=14939745
Not "vacuum tubes"... (◔_◔)
Some rats are going for the ride of their lives...