I think there's a 2MW test turbine off Scotland which I think is the biggest in the world.

https://www.bbc.co.uk/news/uk-scotland-north-east-orkney-she...

Just not as cost effective as wind, which got to piggyback of onshore turbine development.

We don't see large tidal power installations because they are not every economical so far. In theory there's a lot of energy to be won, but the salt water causes corrosion issues, and maintenance gets expensive quickly

This is a very good post. I never before considered the issue of corrosion. To that point, does this also affect offshore wind power generation (turbines)? I guess the difference will be: the turbine is not underwater!

offshore wind is much less effected because all the complicated parts are 100 feet up, and much easier to partially seal.

on the other hand its 100% reliable and needs no fuel, does notndepend on drought, etc.