What is Tidal Stream Energy?

The tides are caused by the gravitational forces of the sun and moon moving the seas around the surface of the earth. It is this movement of water that is used to generate electricity.

In a few places the location of land masses and the shape of the seabed magnifies the movement of the sea to create an area of great tidal energy. The west coast of Anglesey and Holy Island is one of these places with currents of up to 3.7 m/s or 7 knots.

Electricity generated from tidal energy is renewable, low carbon, clean and reliable.


How is tidal energy converted into electricity?

Tidal energy devices contain three components:

  1. Tidal energy convertors which use the movement of the water to slowly rotate a generator which then produces electricity
  2. A structure to hold the tidal energy converters in the water
  3. A foundation or anchor to hold the device in place


Moving and electricity-generating parts of the devices are underwater.


What do tidal energy devices look like?

There are many different designs of tidal energy converters – some are fully submerged in the sea and have parts that may or may not be seen above the surface; others float on the surface whilst others may be anchored mid water. The images below are only illustrative examples of the types of technology that could be deployed at the Morlais zone.