Waves are generated by the wind blowing over a distance of water (a fetch). As short waves become steeper, they break down and their energy flows into longer, more stable waves. Some time after the end of a given fetch, a set of wind-waves will arrive as a low frequency swell. Since there is a lot going on at sea, a given spot in the ocean often has many sets of different wind waves and swells passing by at different directions.
Waves are in fact a concentrated form of solar energy. Uneven heating of the earth's surface causes wind. The wind causes the waves.
Energy Needs and Wave Energy
New forms of energy are needed. Oregon has a "Renewable Portfolio Standard" that states that Oregon's goal is for 25% renewable energy for all large utilities (PGE, Pacificorp, EWEB) and 10% and 5% renewable energy for small utilities by 2025.Energy exists in the ocean in several forms -- as salinity, temperature differential, currents, tidal, and wave. Wave is one of the largest of the marine resources, and most broadly accessible. Compared to other renewables, wave energy has a higher energy density, a higher availability (80 – 90%), and better predictability.
How Much Wave Energy is Out There
It is estimated that if 0.2% of the ocean’s untapped energy could be harnessed, it could provide power sufficient for the entire world. That's quite the statement. But what does this mean to the average person? Here are some facts to give perspective:
W = watt
kW = kilowatt (1 thousand watts)
MW = megawatt (1 million watts)
GW = gigawatt (1 billion watts)
Looking at marine renewable energy: