Climate change, declining fossil fuel supplies, security of supply, and the cost of energy are key challenges facing society today. Wave energy could play a serious contributing role in the decarbonisation and energy self-sufficiency of peripheral nations around the word.
Wave energy is predominantly a third hand form of solar energy
The differential heating of the Earth’s surface creates winds which transfer energy to the water surface.
Studies indicate that the global theoretical wave energy resource is of the order of two to four terawatts – this is the actual power in the waves.
The UK has some of the best wave energy resource in the world due to strong westerly Atlantic winds: an estimated 35% of the European wave resource.
The practical resource that could be economically extracted from UK waters is predicted to be between 7 and 10 GW (Carbon Trust, 2012) (Mackay, 2008), with the most significant contribution offshore from the west coast of Scotland. The upper limit is equivalent to approximately 18% of UK peak demand (60 GW).
The wave energy resource is easier to forecast and less variable than the wind and also has a higher energy density.
Also, as it is related closely to wind speed, it is larger in winter when demand is higher. However there are technical and economic challenges which mean that the technology has not yet made the transition into commercial maturity.
At a particular location the factors which will have the greatest impact on the extractable energy are the wave height and wave period, as well as the directionality. The sea state at a particular location is characterised with a frequency spectrum: relating the wave frequency to the wave spectral density, a measure of the energy at each frequency. A development will also be assessed by studying the environmental impacts of the scheme on the surrounding ecosystem and other sea users.