Soon, there may be 200 tidal power turbines in Kaipara Harbor, New Zealand that will generate 200MW.
There has been an operational tidal power plant off the Devon coast in England since 2003.
These tidal power turbines operate virtually the same as a wind turbine, except they are underwater, revolve slowly and thus are no danger to sea life, and “research suggests they have the potential to be four times more efficient than wind turbines of a similar size.”