From M Messiter.
HARRY McRandle’s report on the proposal for a barrage in St Aubin’s Bay was very interesting.

However, he neglects to mention the possibility of combining a barrage with a number of open-sea turbines, such as are proposed around Alderney, as an improvement on the majority of tidal power schemes. The problem is that their power output varies with the state of the tide.

Open-sea turbines produce most power when the tide is running at its fastest, ie around half-tide (and none in the slack water at high and low tide.) A turbine in a barrage produces power in proportion to the difference in water levels on either side of the barrage, so it should be possible to have it producing maximum power at high and low tide when the open-sea turbines are ineffectual.

The barrage would need to be split into two pools, one to generate near high tide (emptied at low tide and generating by allowing water to flow in) and one to generate near low tide (filled at high tide and generating by allowing water to flow out.)

Then we have only to decide as to whether to size the scheme large enough that it provides all the electricity we need during neap tides and sell the surplus from spring tides or make it smaller and buy the shortfall when the tides are neaping from somewhere else (or even try to depress demand by raising the price during neap tides).

I jalouse we could build our own nuclear power station on a difficult site like the Paternosters for less than the cost of the above.

Andrew Carnegie is supposed to have said that innovation doesn’t pay; I believe that we would be well advised to let someone else find out with their money what works before we commit large amounts of our money to such schemes.
Le Boulevard Cottage,
Mont de Rozel,
St Martin.