Tidal energy is expensive - sea water is very corrosive and under water maintenance access isn't cheaply solved. Also you need to retain access for ships and su

Tidal energy is expensive - sea water is very corrosive and under water maintenance access isn't cheaply solved. Also you need to retain access for ships and subs. The UK has the second highest tidal ranges in the world and is probably a world leader, we still generate nearly no energy from tidal.