Twice a day the oceans rise and fall due to tides.  This movement of water contains a great deal of energy.  This energy can be harnessed as tidal power.

Due to the complexity of these projects they tend to be on a major scale.  The UK is currently pioneering test projects of this technology.  It is hoped that, in the future, tidal power could supply up to 20% of the UK’s energy demand.

Scottish Power Renewables are currently developing a number of tidal power projects.  Read more – https://www.scottishpowerrenewables.com/pages/tidal_energy.aspx