Power Generation (not sure if this belongs here)

Feel free to delete this if it doesn't belong.
So I've always had a side interest in power generation. Specifically renewable energy, not so much for the hippie aspect of it but because it seems like a fun "puzzle" to work within the constraints renewable sources impose (reliability, accessibility etc.). Anyways, here's the idea.

You can build a sea wall extending from the shore and encapsulating a section of water. Water flows in during high tide, and during low tide it can be allowed to flow out through turbines to generate electricity same as a hydroelectric dam. I suppose you could generate electricity as it flows in, but the flow is much slower and more irregular, so I'm not sure it will work well or be worth it. This can have the disadvantage of only working while the tide is out, but if you build a second reservoir like this and let it drain during low tide,during high tide you'll be able to let water flow from the first reservoir to this one to generate electricity during high tide. This second reservoir can be smaller since it will only be used some of the time

A couple of things I find interesting about this idea is that:

You essentially create an artificial estuary(?) or giant tide pool. I don't think this is super damaging to the environment? I could be wrong, but seems like a perfect environment for many fish etc.
It would be pretty regular and reliable as a power source, the tides come in and out whether it is rain or shine, calm or windy. Plus it has the same built in energy storage mechanism as hydroelectric dams, unlike solar/wind which need separate energy storage for their off hours.
It scales well, due to the square law, the volume of water you encapsulate (and therefore your energy generation potential) grows faster than the length of the wall. Double the length of the wall, quadruple your energy capacity.
I'm pretty sure it's feasible, there's an entire country in Europe that relies on similar structures to stay dry.

Plus, I don't think people would mind it very much. Open up the top of the sea wall to the public like a pier, turn it into an attraction. If that doesn't work tell them it's an anti shark defence wall. Or that it'll keep the Mexicans out. Lots of creative uses you can use to sell it to politicians.
This only works on the shore, but hey it's something. If you're super committed and have money to burn you can bore a hole and bring the sea inland. More realistically maybe move power generation seaside and use HVDC transition to take it inland?

I personally think localised energy generation and storage should be a big part of the future. It's much easier and less harmful to slap a wind turbine on every roof than clear a large section of land to make a wind farm. Even more effective in areas that build out rather than up. A lot of things I think are more efficient and easier on a localised per house basis, especially energy storage.

[en.wikipedia.org]

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"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

Ahh, makes sense that it's already been implemented. I wonder why it's not more widely used though.