3. Potential tidal power sites around the world

The world's tidal power potential is estimated at around 250 GW, including 15 GW in France and 18 GW in the UK. The main constraint comes from the cyclical nature of tidal heights, which limits the plant's operating time at full power to 25% of the year, instead of 50% or more for conventional hydroelectricity. This limits global production potential to around 500 TWh/year, on the order of magnitude of hydroelectricity production from units of less than 10 MW.

Very detailed studies have been undertaken for the following developments :

• Chausey Islands (15 GW, 30 TWh/year);

• Severn Estuary (8.6 GW, 17...