An article on the French tidal energy schemes appeared four years ago in this Journal (16, 51). One of these was planned for the estuary of the Ranee, a small coastal river that falls into the Channel between Dinard and St. Malo, the other for the extensive sea-area stretching from MontSaint-Michel to the Chausey Islands, and from Cancale to Granville. These schemes had been drawn up in the years immediately following the second world war, at a time when the power-outlook in France seemed somewhat gloomy: demand was increasing continually with no quickly available new source in sight. It was, it is true, believed that ultimately nuclear energy might well be applied in industry but the time-lag was over-estimated and, in addition, it was feared that the cost would not be competitive. Tidal energy, therefore, was hailed as a welcome solution, and it seemed no wild dream to envisage its exploitation over so wide an area as the bay of Mont-Saint-Michel.

It was this that lay behind the Chausey Islands tidal energy scheme. Hitherto, hydraulic power had been drawn only from rivers; the sea might raise unexpected problems and it would have been rash to embark on so far-reaching an enterprise without first finding the answer to all the difficulties encountered on a smaller scale. In 1950 the Ranee estuary was accordingly chosen as a pilot-scheme, on a power-producing scale of about one-fiftieth. Initial studies were immediately pushed ahead, and building started at the beginning of 1961. Progress was rapid, but so much was involved that it took five years to complete the civil engineering work and another year to finish installing the equipment. Like all great enterprises that do credit to the nation's industry and contribute to the development of its economy, the plant was officially opened by the President of the French Republic on 26 November 1966.