"Think about the movement of the waves, the ebb and flow, the to-and-fro motion of the tides, the ocean is a vast amount of lost power," wrote Victor Hugo in his novel Ninety-Three. However, as far back as the XIIth century, man had already understood how to harness this inexhaustible force by building tide-driven mills along the coast.

In the Rance estuary, near Mont Saint-Michel, some of these facilities were still in operation at the turn of the century. At high tide, small creeks, closed off by a dam, were filled by the flow. The gates of the dam were then lowered, and water now flowed with the ebb tide through the mill blade wheel.