Wave power

This article is about transport and capture of energy in ocean waves. For other aspects of waves in the ocean, see Wind wave. For other uses of wave or waves, see Wave (disambiguation).
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Wave power is the capture of energy of wind waves to do useful work – for example, electricity generation, water desalination, or pumping water. A machine that exploits wave power is a wave energy converter (WEC).

Waves are generated primarily by wind passing over the sea's surface and also by tidal forces, temperature variations, and other factors. As long as the waves propagate slower than the wind speed just above, energy is transferred from the wind to the waves. Air pressure differences between the windward and leeward sides of a wave crest and surface friction from the wind cause shear stress and wave growth.[1]

Wave power as a descriptive term is different from tidal power, which seeks to primarily capture the energy of the current caused by the gravitational pull of the Sun and Moon. However, wave power and tidal power are not fundamentally distinct and have significant cross-over in technology and implementation. Other forces can create currents, including breaking waves, wind, the Coriolis effect, cabbeling, and temperature and salinity differences.

As of 2023, wave power is not widely employed for commercial applications, after a long series of trial projects. Attempts to use this energy began in 1890 or earlier,[2] mainly due to its high power density. Just below the ocean's water surface the wave energy flow, in time-average, is typically five times denser than the wind energy flow 20 m above the sea surface, and 10 to 30 times denser than the solar energy flow.[3]

In 2000 the world's first commercial wave power device, the Islay LIMPET was installed on the coast of Islay in Scotland and connected to the UK national grid.[4] In 2008, the first experimental multi-generator wave farm was opened in Portugal at the Aguçadoura wave park.[5] Both projects have since ended. For a list of other wave power stations see List of wave power stations.

Wave energy converters can be classified based on their working principle as either:[6][7]

  • oscillating water columns (with air turbine)
  • oscillating bodies (with hydroelectric motor, hydraulic turbine, linear electrical generator)
  • overtopping devices (with low-head hydraulic turbine)
  1. ^ Phillips, O.M. (1977). The dynamics of the upper ocean (2nd ed.). Cambridge University Press. ISBN 978-0-521-29801-8.
  2. ^ Christine Miller (August 2004). "Wave and Tidal Energy Experiments in San Francisco and Santa Cruz". Archived from the original on October 2, 2008. Retrieved August 16, 2008.
  3. ^ "Wave energy and its utilization". Slideshare. June 1, 1999. Retrieved April 28, 2023.
  4. ^ "World's first commercial wave power station activated in Scotland". Archived from the original on August 5, 2018. Retrieved June 5, 2018.
  5. ^ Joao Lima. Babcock, EDP and Efacec to Collaborate on Wave Energy projects Archived September 24, 2015, at the Wayback Machine Bloomberg, September 23, 2008.
  6. ^ Falcão, António F. de O. (April 1, 2010). "Wave energy utilization: A review of the technologies". Renewable and Sustainable Energy Reviews. 14 (3): 899–918. doi:10.1016/j.rser.2009.11.003. ISSN 1364-0321.
  7. ^ Madan, D.; Rathnakumar, P.; Marichamy, S.; Ganesan, P.; Vinothbabu, K.; Stalin, B. (October 21, 2020), "A Technological Assessment of the Ocean Wave Energy Converters", Advances in Industrial Automation and Smart Manufacturing, Lecture Notes in Mechanical Engineering, Singapore: Springer Singapore, pp. 1057–1072, doi:10.1007/978-981-15-4739-3_91, ISBN 978-981-15-4738-6, S2CID 226322561, retrieved June 2, 2022