From the photo, it looks like in all the space this thing takes up, you could have just planted a regular tree. It doesn’t make sense as an alternative in urban areas with limited space or whatever if it uses up just as much space.

That’s aside from the fact that trees are helpful in keeping the temperature down during summer. I doubt whether this thing does the same.

You know, this thing would have been cool as an Indoors wall thingy in malls and such, since algae doesn’t need as much maintenance as houseplants and would produce more oxygen too. Placing the tank outside is a strange decision, it simply doesn’t match with the streets stylistically or functionally and will require regular repairs and cleaning from damages of the elements and filth that would accumulate at extreme speeds.

So years ago something similar to this was floated as a green alternative to street lamps and similar things. Basically big tubes of algae. They actually figured out how to get and store energy from the photosynthesis of the algae and use it to power a light in or above the tank. The crazy part is the efficiency of the algae at removing CO2 from the air. One tank could pull as much CO2 in one year as one tree does in it’s average lifespan. At least that’s what they reported. Course it would take a ton of maintenance and not sure what you do with the waste algae. As a method for sequestering CO2 it has merritt. Course then there’s always the thought of how much CO2 is generated from actually making one of said tanks. That I do not know but I still don’t think it’s a bad idea. Not really as a replacement of trees though. Hell even in the pictures of this bench thing there are still trees around it. You can see the trunk of a tree behind it and the some branches off to the side on the other image.