Isn't 1,5 - 2MW much the same amount a standard onshore wind turbine would provide?
I assume the tidal power generation must have some advantages (e.g. more constant output?)
The main benefit, I think, is having multiple generation sources as these will smoothen out any power drops from other sources.
No, perhaps 10 years ago. Offshore turbines currently being installed are in the range of 7-8MW. 10-12MW isn't far off.