12. Conclusion

Tidal power plant developments in France have three advantages:

• generate 100 TWh/year (20% of electricity) in renewable forms at a lower cost than solar or offshore wind power;

• stop the retreat of cliffs and the filling in of the Somme and Mont Saint-Michel bays;

• promote economic development and employment from Brittany to Pas-de-Calais.

The potential of tidal turbines seems much smaller.