You basically need a few conditions to be met to make this useable: tide needs to be high enough, there needs to be suitable geological formation that enables building of such power plants, it has to be publicly acceptable to build there, and you need to connect it to the grid. The last two can especially cancel eachother out.

However, this assumes you use potential energy. What you are envisioning might be more like current power (so kinetic energy) where I'm not sure what the limitations are. Perhaps it's not too practical to build huge plants underwater in locations with relatively constant current and connect them to the grid