When the world is looking for a way to generate electricity it is always what appears to be the cheapest and easiest solution that is used. The prime concern is not to spend too much money on the project, hence the proliferation of huge toy windmills, cheap, ugly and not that efficient.
Tide surges and other tidal systems are considered too difficult to install and maintain and yet $millions are spent on offshore wind farm maintenance and supply vessels that can not get out to the offshore wind-farms in serious weather when manpower is probably essential to prevent a meltdown or failure of one of the many “windmills in the Sea”. AS the worlds weather gets worse, according to many sceptics involved with climate change, what is the point of putting any form of power generation in the offshore areas of any land mass!!