Renewable energy from the marine environment is primarily from three sources: wind, waves and tides. This SEA commissioned by Scottish Executive will focus on marine renewables i.e. wave and tidal energy.

Tidal Energy

Tidal energy devices are designed to capture the energy created by the natural flow and ebb of coastal tidal waters. Tides are the effect of the moon's and sun's gravitational pull on earth. The speed of tidal flows is often increased in areas where water is forced through narrow channels e.g. around headlands, inlets or straits, and these are the primary areas of interest for tidal energy.

Wave Energy

Wave energy devices are designed to harness the energy generated by the movement of waves. Wave energy devices can either be placed on the shoreline or in deeper water. Factors influencing their location include water depth (different devices have different requirements), distance from the shore (predominantly dictated by the economics of power supply back to shore), wave conditions, seabed and coastal materials/conditions, and external influences such as navigation requirements, fishing, wreck locations, military exercise areas, and environmental designations.