Tidal power operates by building a barrier across a river estuary.
The tidal flow drives turbines to produce electricity. Europe's only tidal power station is at Rance in Northern France. A number of sites in the U.K could be developed to provide tidal power. The drawback is that these schemes affect the habitat of seabirds and fish because they alter the tidal currents. Also, barrage will only provide power for about 10 hours per day.