This looks promising, simple but clever use of tidal power.

World's first lagoon power plants unveiled in UK

When people refer to "nuclear", they usually think of either fission or fusion (both of which are potentially disastrous if a failure occurs). However, there IS another option, and it's far safer, ~AND~ more efficient than either of the other 2 "nuclear" options. Ever hear of a Thorium reactor? Good stuff, and far superior to other methods, but because it's a type of "nuclear" reactor, people get frightened off from even considering it.

(note: a Thorium reactor is a type of Molten Salt Reactor, and as a design, shows great promise.)

Still, so long as it's designed and built responsibly, tidal power generation is a viable method of generating electricity (though it's not as "green" as some would think).

And you're right, Freddy. That structure is absolutely gorgeous.

Nice bit of education right there Dave, I'd heard of Thorium reactors before but wasn't sure of the specifics.

And Dave is quite correct, the Lagoon tidal option isn't as green as it could be which was the reason the Severn Barrage was rejected as it would have devastated the birdlife in the Severn estuary.

http://en.wikipedia.org/wiki/Severn_Barrage

In the Pacific Northwest, mainly in the states of Oregon and Washington, many of the rivers that salmon use to spawn are also used to generate electricity, so the power companies have implemented "salmon ladders" to allow the fish to reach their spawning grounds. I suspect it's the same sort of thing as the eel ladders you mentioned, Freddy.

I don't see why something similar couldn't be used for the tidal generators, though I think the tech involved would likely be somewhat different, given the fact that the flow of water changes from in to out and back on a frequent basis.