The Turning Tide
Where there are suitable estuaries in the world, it’s easy to construct tidal barriers (and this is lunar power), which trap large volumes of water at high tide and use the differing water levels, releasing it at low tide to drive turbines, and then letting it in at high tide and capturing that flow also. There’s been one working very well at La Rance, in France, since 1966. It could have been built bigger and there’s a second stage that could be built which would be just helping themselves to some free energy.
Stephen Salter explains that it’s run by EDF, the French nuclear company who also build in the UK. EDF have never published the costs of the La Rance project, and presumably don’t want to build the second phase because they don’t want the figures to get even better.
It seems like the nuclear industry’s involvement in renewables is for the purpose of discrediting renewables, gathering evidence that they are uneconomic. They shower enthusiasm into the projects at the beginning, but when the costs start getting good and they start to make economic sense, then they hide the findings and/or lie about them.
Actually, Wyre Tidal Energy, who have long had plans for a barrage on the River Wyre in Lancashire, had these figures about La Rance:
With a peak rating of 240 Megawatts, generated by its 24 turbines, it has an annual output of approximately 600 GWh. The development costs were high but these have now been recovered and electricity production costs are lower than that of nuclear power generation (1.8c per kWh, versus 2.5c per kWh for nuclear).
That’s been the situation for renewable technology, that the development costs are high, but once in place, those costs are recovered and after that it’s much cheaper; even much, much cheaper.
Here’s a recently announced scheme for Swansea Bay.
This is a proposal from Tidal Lagoon Power, who want to build four lagoons around Britain to produce 7.3 GigaWatts, over 10% of the UK’s electricity demand. The whole idea of tidal lagoons is very interesting and offers protection from storms:
There is enormous power in the sea and marine energy will have a huge role to play in the future in all sorts of places. But for another view about Wave Power here’s a piece by Dr Kerry Black. Dr Black is a surfer . . . he says to keep energy simple and that some things are sacrosanct. We think he’d like kites.