[lelag]

It's been done. Biggest one is Sihwa Lake Tidal Power Station[1] and France had a 240MW tidal plant since the 60s [2].

This type of project has been few and far between and I would guess they might be very costly to build and maintain compared to the harvested energy.

[1] https://en.wikipedia.org/wiki/Sihwa_Lake_Tidal_Power_Station [2] https://en.wikipedia.org/wiki/Rance_Tidal_Power_Station

[macNchz]

This is interesting–it made me wonder if this had ever been considered on NYC's East River, which is a tidal estuary with strong currents. Turns out there's been a company working on it for a while, with free-moving turbines rather than something that spans the whole thing: https://www.energy.gov/eere/water/articles/tidal-testing-und...