Green Energy

The problem with these structures is usually small marine life - they tend to need frequent maintenance to remove barnacles and whatnot.

Having your smooth walls and turbines lined with barnacles tends to impact performance significantly.

You gotta remember that any form of energy only needs to be less damaging than the alternative to be better. When the alternative is coal, every other form of energy is less damaging.

Tidal turbines are designed to be noisy enough to deter marine life but not so noisy that there are detrimental health and ecological effects. Not sure how successful this strategy is, but the scale of deployments is still small and more study and monitoring should be done before the scale makes big impacts from even small effects.

Here's a blog post from an engineering firm that works on these issues:
https://eandt.theiet.org/2024/03/21/designing-tidal-turbines-are-safe-marine-life