On 14/05/2010 13:49, Bruce wrote:

At least the Tidal Barrage at Rance in France has survived since 1966.


But La Rance isn't a tidal stream power station. It has a dam which
fills at high water and generates power by allowing the retained water
to escape through turbines as the tide falls.

But it does have turbines operating in a marine environment.

The most important thing to learn from La Rance is that, 44 years
later, no-one has built anything like it. Tidal barrages involve
massive capital cost, very low returns, an almost infinite payback
period and of course huge environmental opposition.

Take out the environmental opposition and the Severn Barrage would
almost certainly go ahead.

And at the end of it all, you get uneconomic electricity at the wrong
time of day most days.

Uneconomic electricity is what you get from wind turbines.

I suppose if I mentioned Lynmouth or Strangford Lough you would rubbish
those enterprises as well.