Renewable energy from the marine environment is primarily from three sources: offshore wind, waves and tides. These three sources of energy will be the main focus of this SEA commissioned by DETI.

Wave and 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.  These tend to be the primary areas of interest for tidal energy development.
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 and seabed and coastal materials/conditions.
The location of wave and tidal devices is also influenced by a number of external factors such as navigation requirements, fishing, wreck locations, military exercise areas, and environmental designations.
The technology to harness marine or “wet” renewables (wave and tidal) has proven much more difficult and costly to develop than wind technology but it can produce a more consistent, predictable, and potentially very significant level of energy.  Following world wide technological developments the marine renewable sector is now entering an important open sea testing phase which could promise the emergence of commercially viable technologies e.g. the Wave Power Pelamis project off the coast of Portugal is the world’s first commercial wave farm. The installation of the 1.2 MW MCT Sea Gen commercial demonstration project at Strangford Lough in April 2008 is a key development in terms of harnessing tidal energy.

Electricity Grid Connections and Capacity
It is widely recognized that the existing grid network in Northern Ireland (and across the Republic of Ireland) is currently operating at full capacity and requires expansion in certain locations to support ongoing economic and residential development and expansion.     These limitations in the capacity and coverage of the grid network also limit its ability to accommodate electricity generated from new renewable energy developments, which could potentially constrain the future development of offshore wind, wave and tidal energy.