Wave power

From ArticleWorld

Wave power refers to the harnessing of the ocean’s surface wave energy in order to generate electricity. The ocean’s waves can also be used for desalination and collection of water in reservoirs.

Power generation

Wave power is a type of renewable energy; there is no chance of exhaustion. Often confused with tidal power and power derived from ocean currents, wave power depends on the height, speed, wavelength and density of waves. Wind speeds – usually referred to as gales – determine the nature of waves and their sizes. The topography of the ocean bed also plays an important role in dispersing the energy of the waves.

Wave power for energy generation is best harnessed in the temperate zones of both the northern and the southern hemispheres. The westerlies which are present in these zones usually are very prominent and strongest in the colder season.

Wave energy

Wave energy is highest at the surface of the ocean and reduces at an exponential rate deeper within the ocean. Wave energy at a deeper level is present as pressure waves. The largest waves whose energy can be tapped can be as high as 15 metres, not considering destructive storms or tsunamis.

The energy possessed by waves can be calculated by the formula:

Energy (in kw/m) = kH2T – 0.52T,

• Where k = constant,
• H = height of wave in metres from crest to trough
• T = time period of the wave in seconds (from crest to crest)

Water power devices are deployed to harness the wave and attenuate it for the purpose. Pontoons can be used to run generators by wave action. Another method could be the use of compressed air from wave action in order to drive generator vanes. Reservoirs may also be used; once filled by sea water from waves, they can be released to run turbine generator sets.

Future scope of wave power

Wave power can provide much more energy than other forms of ocean energy. This form of energy can be exploited in many locations in the world where winds prevail and long coastal belts are present. The United Kingdom is particularly suited for this. Over five percent of electricity requirements in suitable situations can be adhered to with the help of surface wave potential.