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| {{about|transport and the capture of energy in ocean waves|other aspects of waves in the ocean|Wind wave|other uses of wave or waves|Wave (disambiguation)}}
| | It is when a lender agrees to accept considerably less than what is owed as "payment in total", in an work to avoid the foreclosure process. The financial institution agrees to "write-off" and forgives the remaining portion owed.<br><br> |
| {{Use mdy dates|date=October 2012}}
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| {{Renewable energy sources}}
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| {{Sustainable energy}}
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| '''Wave power''' is the transport of energy by [[ocean surface wave]]s, and the capture of that energy to do useful [[mechanical work|work]] – for example, [[electricity generation]], [[water desalination]], or the [[pump]]ing of water (into reservoirs). Machinery able to exploit wave power is generally known as a '''wave energy converter''' (WEC).
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| Wave power is distinct from the diurnal flux of [[tidal power]] and the steady gyre of [[ocean currents]]. Wave-power generation is not currently a widely employed commercial technology, although there have been attempts to use it since at least 1890.<ref>{{cite web|url=http://www.outsidelands.org/wave-tidal3.php|title=Wave and Tidal Energy Experiments in San Francisco and Santa Cruz|author=Christine Miller|accessdate=2008-08-16|date=August 2004}}</ref> In 2008, the first experimental [[wave farm]] was opened in Portugal, at the [[Aguçadoura Wave Park]].<ref>Joao Lima. [http://www.bloomberg.com/apps/news?pid=21070001&sid=aSsaOB9qbiKE Babcock, EDP and Efacec to Collaborate on Wave Energy Projects] ''Bloomberg'', September 23, 2008.</ref> The major competitor of wave power is [[offshore wind power]].
| | Get the giving details. 2. If the NOI recommended by the Seller will not include the financial debt services anticipated and produce a sensible income stream, don't waste a good deal of time. It doesn't issue how cute, extravagant or amazing the house is, if it gained't cash movement; it must be a no-go!<br><br>When you initial meet up with with the operator you require to remember the 1st rule of negotiating and that is by no means be the initial one to point out a cost. The worst factor you can do is say everything about price tag. If they press you explain to them you're not an specialist in home values and you would need to have to make some calculations after hunting at their residence. Till then you don't have a clue. Ask them what they think the home is really worth and why. What ever they inform you don't act way too fascinated and don't disagree with them.<br><br>Repairs are likely to be in which you a lot of negotiating. Ask the proprietor about repairs and publish them down. Point out each minor factor you see that is not perfect. On every product ask him what it would value to fix it. Attempt to get him to explain to you a range of charges and publish down the highest amount. Question him if he's sure the repair can be completed for that sum often he'll enhance the quantity. Make positive to use the greatest volume in the rest of negotiations. When you commence introducing up the fix quantity this will help reduce his worth. Get a good deal of notes concerning the repairs. The a lot more you compose about them the more it makes the owner mindful of them.<br><br>I inform you this story due to the fact we face the very same situation right now and will assist you realize the need to have for keeping precious metals like gold and silver. We have now developed from the use of gold to the use of paper pounds across the globe. These dollars exactly where as soon as redeemable for gold. Indeed! The U.S dollar was once backed by gold and was as excellent as gold. President Nixon manufactured Julius Caesar choice and made the decision to start Arthur Falcone chopping corners and ultimately took the country off of the Gold Normal.<br><br>Most can not even land a strong occupation. Indeed they have a college diploma and a mountain of debt which they are now locating was a huge miscalculation. The N.I.N.J.A era stands for No Job, No Earnings and No Belongings. My job is to aid this generation of individuals secure cash flow and belongings so they can remodel their lives for the foreseeable future and a wonderful way to accumulate assets with tiny money is in Gold and Silver Investing.<br><br>Especially the initial time. You know, if they've been there for a calendar year and they want an additional 10 times or some thing, the entire world is not heading to conclude. But the first time they're late you have to arrive down on them with almost everything you obtained and allow them know you're not heading to take late payments and charge them the late payment charge. You have to since if you don't, you're environment a bad precedent.<br><br>As a issue of fact, it is considerably a lot more of a confident factor to use your IRA income to purchase [http://www.foodspotting.com/61391 Arthur Falcone] than it is to gamble with shares and bonds. real estate, usually speaking, is a much much more secure marketplace and one particular the place it is less complicated for you to handle your investments.<br><br>One other [http://Www.tumblr.com/tagged/merchandise merchandise] to note is that the reserves calculation for a financed property is dependent on the price of the financed house calculated on a month-to-month basis. In addition all demands Arthur Falcone on reserves are based on Fannie Mae's new definition of "reserves". For far more information on how Fannie defines this, check out the Fannie Mae Announcement 09-02.<br><br>Hiring a Virginia Beach real estate agent is a single of the greatest methods to find the appropriate area Arthur Falcone to transfer into. Nonetheless, you have to be cautious whilst choosing an agent for there are several inexperienced agents who are searching to make the most of the actual estate increase below. So constantly hire an agent with a great keep track of report driving him/her. |
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| ==Physical concepts==
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| [[File:Elliptical trajectory on ripples.svg|thumb|300px|When an object bobs up and down on a ripple in a pond, it experiences an elliptical trajectory.]]
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| [[File:Wave motion-i18n-mod.svg|thumb|right|300px|Motion of a particle in an ocean wave.<br />
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| '''A''' = At deep water. The [[orbit]]al motion of fluid particles decreases rapidly with increasing depth below the surface.<br />
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| '''B''' = At shallow water (ocean floor is now at B). The elliptical movement of a fluid particle flattens with decreasing depth.<br />
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| '''1''' = Propagation direction. <br />
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| '''2''' = Wave crest.<br />
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| '''3''' = Wave trough.]]
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| [[File:Orbital wave motion-Wiegel Johnson ICCE 1950 Fig 6.png|thumb|right|300px|Photograph of the water particle orbits under a – progressive and periodic – [[surface gravity wave]] in a [[wave flume]]. The wave conditions are: mean water depth ''d'' = {{convert|2.50|ft|m|abbr=on}}, [[wave height]] ''H'' = {{convert|0.339|ft|m|abbr=on}}, wavelength λ = {{convert|6.42|ft|m|abbr=on}}, [[period (physics)|period]] ''T'' = 1.12 s.<ref>Figure 6 from: {{citation |first1=R.L. |last1=Wiegel |first2=J.W. |last2=Johnson |year=1950 |contribution=Elements of wave theory |title=Proceedings 1st International Conference on Coastal Engineering |location=Long Beach, California |publisher=[[American Society of Civil Engineers|ASCE]] |pages=5–21 |url=http://journals.tdl.org/ICCE/article/view/905 }}</ref>]]
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| :''See energy, [[power (physics)|power]] and [[mechanical work|work]] for more information on these important physical concepts. see [[wind wave]] for more information on ocean waves.''
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| Waves are generated by wind passing over the surface of the sea. As long as the waves propagate slower than the wind speed just above the waves, there is an energy transfer from the wind to the waves. Both air pressure differences between the upwind and the lee side of a wave [[crest (physics)|crest]], as well as friction on the water surface by the wind, making the water to go into the [[shear stress]] causes the growth of the waves.<ref name=Phillips/>
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| [[Wave height]] is determined by wind speed, the duration of time the wind has been blowing, fetch (the distance over which the wind excites the waves) and by the depth and topography of the seafloor (which can focus or disperse the energy of the waves). A given wind speed has a matching practical limit over which time or distance will not produce larger waves. When this limit has been reached the sea is said to be "fully developed". | |
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| In general, larger waves are more powerful but wave power is also determined by wave speed, [[wavelength]], and water [[density]].
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| [[Ocean surface wave#Science of waves|Oscillatory motion]] is highest at the surface and diminishes exponentially with depth. However, for [[standing waves]] ([[clapotis]]) near a reflecting coast, wave energy is also present as pressure oscillations at great depth, producing [[microseism]]s.<ref name=Phillips>{{cite book| first=O.M. | last=Phillips | title=The dynamics of the upper ocean |publisher=Cambridge University Press | year=1977 | edition=2nd | isbn=0-521-29801-6 }}</ref> These pressure fluctuations at greater depth are too small to be interesting from the point of view of wave power.
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| The waves propagate on the ocean surface, and the wave energy is also transported horizontally with the [[group velocity]]. The mean transport rate of the wave energy through a vertical [[plane (mathematics)|plane]] of unit width, parallel to a wave crest, is called the wave energy [[flux]] (or wave power, which must not be confused with the actual power generated by a wave power device).
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| ===Wave power formula===
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| In deep water where the water depth is larger than half the [[wavelength]], the wave [[energy flux]] is<ref group=lower-alpha>The energy flux is <math>P = \tfrac{1}{16} \rho g H_{m0}^2 c_g,</math> with <math>c_g</math> the group velocity, see {{Cite book
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| | publisher = McGraw-Hill Professional
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| | isbn = 978-0-07-134402-9
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| | last = Herbich
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| | first = John B.
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| | title = Handbook of coastal engineering
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| | year = 2000
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| | nopp = yes
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| | pages = p. A.117, Eq. (12)
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| }} The group velocity is <math>c_g=\tfrac{g}{4\pi}T</math>, see the collapsed table "''Properties of gravity waves on the surface of deep water, shallow water and at intermediate depth, according to linear wave theory''" in the section "''[[#Wave energy and wave energy flux|Wave energy and wave energy flux]]''" below.</ref>
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| :<math>
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| P = \frac{\rho g^2}{64\pi} H_{m0}^2 T_e
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| \approx \left(0.5 \frac{\text{kW}}{\text{m}^3 \cdot \text{s}} \right) H_{m0}^2\; T_e,
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| </math>
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| with ''P'' the wave energy flux per unit of wave-crest length, ''H''<sub>''m0''</sub> the [[significant wave height]], ''T''<sub>''e''</sub> the wave energy [[period (physics)|period]], ''ρ'' the water [[density]] and ''g'' the [[Earth's gravity|acceleration by gravity]]. The above formula states that wave power is proportional to the wave energy period and to the [[Square (algebra)|square]] of the wave height. When the significant wave height is given in metres, and the wave period in seconds, the result is the wave power in kilowatts (kW) per metre of [[wavefront]] length.<ref>{{cite book|title=Waves in ocean engineering|year=2001|publisher=Elsevier|location=Oxford|isbn=0080435661|pages=35–36|author=Tucker, M.J.|edition=1st ed.|coauthors=Pitt, E.G.|editor=Bhattacharyya, R., McCormick, M.E.|chapter=2}}</ref><ref>{{cite web|url=http://www.esru.strath.ac.uk/EandE/Web_sites/01-02/RE_info/wave%20power.htm|title=Wave Power|publisher=[[University of Strathclyde]]|accessdate=2008-11-02}}</ref><ref name="ocs">{{cite web|url=http://www.ocsenergy.anl.gov/documents/docs/OCS_EIS_WhitePaper_Wave.pdf|format=PDF|title=Wave Energy Potential on the U.S. Outer Continental Shelf|publisher=[[United States Department of the Interior]]|accessdate=2008-10-17}}</ref><ref>[http://www.scotland.gov.uk/Publications/2006/04/24110728/10 Academic Study: Matching Renewable Electricity Generation with Demand: Full Report]. Scotland.gov.uk.</ref>
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| Example: Consider moderate ocean swells, in deep water, a few km off a coastline, with a wave height of 3 m and a wave energy period of 8 seconds. Using the formula to solve for power, we get
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| :<math>
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| P \approx 0.5 \frac{\text{kW}}{\text{m}^3 \cdot \text{s}} (3 \cdot \text{m})^2 (8 \cdot \text{s}) \approx 36 \frac{\text{kW}}{\text{m}},
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| </math>
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| meaning there are 36 kilowatts of power potential per meter of wave crest.
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| In major storms, the largest waves offshore are about 15 meters high and have a period of about 15 seconds. According to the above formula, such waves carry about 1.7 MW of power across each metre of wavefront.
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| An effective wave power device captures as much as possible of the wave energy flux. As a result the waves will be of lower height in the region behind the wave power device.
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| ===Wave energy and wave-energy flux===
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| In a [[sea state]], the average energy density per unit area of [[gravity wave]]s on the water surface is proportional to the wave height squared, according to linear wave theory:<ref name=Phillips/><ref name=Goda>{{cite book | first=Y. | last=Goda | title=Random Seas and Design of Maritime Structures | year=2000 | publisher=World Scientific | isbn=978-981-02-3256-6 }}</ref>
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| :<math>E=\frac{1}{16}\rho g H_{m0}^2,</math> <ref group=lower-alpha>Here, the factor for random waves is {{frac|1|16}}, as opposed to {{frac|1|8}} for periodic waves – as explained hereafter. For a small-amplitude sinusoidal wave <math>\scriptstyle \eta=a\,\cos\, 2\pi\left(\frac{x}{\lambda}-\frac{t}{T}\right)</math> with wave amplitude <math>\scriptstyle a,\,</math> the wave energy density per unit horizontal area is <math>\scriptstyle E=\frac{1}{2}\rho g a^2,</math> or <math>\scriptstyle E=\frac{1}{8}\rho g H^2</math> using the wave height <math>\scriptstyle H\,=\,2\,a\,</math> for sinusoidal waves. In terms of the variance of the surface elevation <math>\scriptstyle m_0=\sigma_\eta^2=\overline{(\eta-\bar\eta)^2}=\frac{1}{2}a^2,</math> the energy density is <math>\scriptstyle E=\rho g m_0\,</math>. Turning to random waves, the last formulation of the wave energy equation in terms of <math>\scriptstyle m_0\,</math> is also valid (Holthuijsen, 2007, p. 40), due to [[Parseval's theorem]]. Further, the [[significant wave height]] is ''defined'' as <math>\scriptstyle H_{m0}=4\sqrt{m_0}</math>, leading to the factor {{frac|1|16}} in the wave energy density per unit horizontal area.<br></ref><ref>{{Cite book
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| | last = Holthuijsen
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| | first = Leo H.
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| | year = 2007
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| | title = Waves in oceanic and coastal waters
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| | publisher = Cambridge University Press
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| | isbn = 0-521-86028-8
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| | location = Cambridge
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| }}</ref>
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| where ''E'' is the mean wave energy density per unit horizontal area (J/m<sup>2</sup>), the sum of [[kinetic energy|kinetic]] and [[potential energy]] density per unit horizontal area. The potential energy density is equal to the kinetic energy,<ref name=Phillips/> both contributing half to the wave energy density ''E'', as can be expected from the [[Equipartition theorem#Potential energy and harmonic oscillators|equipartition theorem]]. In ocean waves, surface tension effects are negligible for wavelengths above a few [[decimetre]]s.
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| As the waves propagate, their energy is transported. The energy transport velocity is the [[group velocity]]. As a result, the wave energy [[flux]], through a vertical plane of unit width perpendicular to the wave propagation direction, is equal to:<ref>{{cite journal | last=Reynolds |first=O. | authorlink=Osborne Reynolds | year=1877 |title=On the rate of progression of groups of waves and the rate at which energy is transmitted by waves | journal=Nature | volume=16 | pages=343–44 | doi = 10.1038/016341c0 |bibcode = 1877Natur..16R.341. }}<br>{{cite journal | title=On progressive waves | author=Lord Rayleigh (J. W. Strutt) | authorlink=Lord Rayleigh | year=1877 | journal=Proceedings of the London Mathematical Society | volume=9 | issue=1 | pages=21–26 | doi=10.1112/plms/s1-9.1.21 }} Reprinted as Appendix in: ''Theory of Sound'' '''1''', MacMillan, 2nd revised edition, 1894.</ref><ref name=Phillips/>
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| :<math>P = E\, c_g, \, \ </math>
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| with ''c<sub>g</sub>'' the group velocity (m/s).
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| Due to the [[dispersion (water waves)|dispersion relation]] for water waves under the action of gravity, the group velocity depends on the wavelength ''λ'', or equivalently, on the wave [[period (physics)|period]] ''T''. Further, the dispersion relation is a function of the water depth ''h''. As a result, the group velocity behaves differently in the limits of deep and shallow water, and at intermediate depths:<ref name=Phillips/><ref name=Goda/>
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| {| class="wikitable collapsible collapsed" style="width:80%; text-align:center;"
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| |-
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| ! colspan="6" | Properties of gravity waves on the surface of deep water, shallow water and at intermediate depth, according to [[Airy wave theory|linear wave theory]]
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| |-
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| ! style="width:10%;"| quantity
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| ! style="width:5%;"| symbol
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| ! style="width:5%;"| units
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| ! style="width:10%;"| deep water<br>( ''h'' > ½ ''λ'' )
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| ! style="width:10%;"| shallow water<br>( ''h'' < 0.05 ''λ'' )
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| ! style="width:10%;"| intermediate depth<br>( all ''λ'' and ''h'' )
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| |- style="height:120px"
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| ! [[phase velocity]]
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| | <math>\displaystyle c_p=\frac{\lambda}{T}=\frac{\omega}{k}</math>
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| || m / s
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| || <math>\frac{g}{2\pi} T</math>
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| || <math>\sqrt{g h}</math>
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| || <math>\sqrt{\frac{g\lambda}{2\pi}\tanh\left(\frac{2\pi h}{\lambda}\right)}</math>
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| |- style="height:120px"
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| ! [[group velocity]]<ref group=lower-alpha>For determining the group velocity the angular frequency ''ω'' is considered as a function of the wavenumber ''k'', or equivalently, the period ''T'' as a function of the wavelength ''λ''.</ref>
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| | <math>\displaystyle c_g= c_p^2 \frac{\partial\left(\lambda/c_p\right)}{\partial\lambda}=\frac{\partial\omega}{\partial k}</math>
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| || m / s
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| || <math>\frac{g}{4\pi} T</math>
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| || <math>\sqrt{g h}</math>
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| || <math>\frac{1}{2} c_p \left( 1 + \frac{4\pi h}{\lambda}\frac{1}{\sinh\left(\displaystyle \frac{4\pi h}{\lambda}\right)} \right)</math>
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| |- style="height:120px"
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| ! ratio
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| | <math> \displaystyle \frac{c_g}{c_p}</math>
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| || –
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| || <math>\displaystyle\frac{1}{2}</math>
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| || <math>\displaystyle 1</math>
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| || <math>\frac{1}{2} \left( 1 + \frac{4\pi h}{\lambda}\frac{1}{\sinh\left(\displaystyle \frac{4\pi h}{\lambda}\right)} \right)</math>
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| |- style="height:120px"
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| ! wavelength
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| | <math>\displaystyle\lambda</math>
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| || m
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| || <math>\frac{g}{2\pi} T^2</math>
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| || <math>T \sqrt{g h}</math>
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| || for given period ''T'', the solution of:<br> <br><math>\displaystyle
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| \left(\frac{2\pi}{T}\right)^2=\frac{2\pi g}{\lambda}\tanh\left(\frac{2\pi h}{\lambda}\right)</math>
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| |-
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| ! colspan="6" | general
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| |- style="height:80px"
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| ! wave energy density
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| | <math>\displaystyle E</math>
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| | J / m<sup>2</sup>
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| | colspan="3" | <math>\frac{1}{16} \rho g H_{m0}^2</math>
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| |- style="height:80px"
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| ! wave energy [[flux]]
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| | <math>\displaystyle P</math>
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| | W / m
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| | colspan="3" | <math>\displaystyle E\;c_g</math>
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| |- style="height:80px"
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| ! angular [[frequency]]
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| | <math>\displaystyle \omega</math>
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| | [[radian|rad]] / s
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| | colspan="3" | <math>\frac{2\pi}{T}</math>
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| |- style="height:80px"
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| ! [[wavenumber]]
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| | <math>\displaystyle k</math>
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| | rad / m
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| | colspan="3" | <math>\frac{2\pi}{\lambda}</math>
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| |}
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| ===Deep-water characteristics and opportunities===
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| Deep water corresponds with a water depth larger than half the wavelength, which is the common situation in the sea and ocean. In deep water, longer-period waves propagate faster and transport their energy faster. The deep-water group velocity is half the [[phase velocity]]. In [[waves and shallow water|shallow water]], for wavelengths larger than about twenty times the water depth, as found quite often near the coast, the group velocity is equal to the phase velocity.<ref name=Dean_Dalrymple>{{cite book | title=Water wave mechanics for engineers and scientists | author=R. G. Dean and R. A. Dalrymple | year=1991 | series=Advanced Series on Ocean Engineering | volume=2 | publisher=World Scientific, Singapore | isbn=978-981-02-0420-4 }} See page 64–65.</ref>
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| ==History==
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| The first known patent to use energy from ocean waves dates back to 1799 and was filed in Paris by Girard and his son.<ref name=cle2002>{{cite journal |author=Clément et al. |year=2002 |title=Wave energy in Europe: current status and perspectives |journal=Renewable and Sustainable Energy Reviews |volume=6 |issue=5 |pages=405–431 |doi=10.1016/S1364-0321(02)00009-6}}</ref> An early application of wave power was a device constructed around 1910 by Bochaux-Praceique to light and power his house at [[Royan]], near [[Bordeaux]] in France.<ref>{{cite web|url=http://www.mech.ed.ac.uk/research/wavepower/0-Archive/EWPP%20archive/1976%20Leishman%20and%20Scobie%20NEL.pdf|format=PDF |title=The Development of Wave Power|accessdate=2009-12-18}}</ref> It appears that this was the first oscillating water-column type of wave-energy device.<ref name=morris2007>{{cite journal |author=Morris-Thomas et al. |year=2007 |title=An Investigation Into the Hydrodynamic Efficiency of an Oscillating Water Column |journal=Journal of Offshore Mechanics and Arctic Engineering |volume=129 |issue=4 |pages=273–278 |doi=10.1115/1.2426992 |last2=Irvin |first2=Rohan J. |last3=Thiagarajan |first3=Krish P.}}</ref> From 1855 to 1973 there were already 340 patents filed in the UK alone.<ref name=cle2002/>
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| Modern scientific pursuit of wave energy was pioneered by [[Yoshio Masuda]]'s experiments in the 1940s.<ref>{{cite web|url=http://www.jamstec.go.jp/jamstec/MTD/Whale/ |title=Wave Energy Research and Development at JAMSTEC|accessdate=2009-12-18 |archiveurl = http://web.archive.org/web/20080701162330/http://www.jamstec.go.jp/jamstec/MTD/Whale/ |archivedate = July 1, 2008}}</ref> He has tested various concepts of wave-energy devices at sea, with several hundred units used to power navigation lights. Among these was the concept of extracting power from the angular motion at the joints of an articulated raft, which was proposed in the 1950s by Masuda.<ref name=ey2006>{{cite conference |url=http://www.iwwwfb.org/Abstracts/iwwwfb21/iwwwfb21_15.pdf |author=Farley, F. J. M. and Rainey, R. C. T. |year=2006 |title=Radical design options for wave-profiling wave energy converters |booktitle=International Workshop on Water Waves and Floating Bodies |location=Loughborough |accessdate=2009-12-18}}</ref>
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| A renewed interest in wave energy was motivated by the [[1973 oil crisis|oil crisis in 1973]]. A number of university researchers re-examined the potential to generate energy from ocean waves, among whom notably were [[Stephen Salter]] from the [[University of Edinburgh]], [[Kjell Budal]] and [[Johannes Falnes]] from [[Norwegian Institute of Technology]] (now merged into [[Norwegian University of Science and Technology]]), [[Michael E. McCormick]] from [[U.S. Naval Academy]], [[David Evans (mathematician)|David Evans]] from [[Bristol University]], Michael French from [[University of Lancaster]], [[John Nicholas Newman|Nick Newman]] and [[C. C. Mei]] from [[MIT]].
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| Stephen Salter's [[1974 in science|1974 invention]] became known as [[Salter's duck]] or ''nodding duck'', although it was officially referred to as the Edinburgh Duck. In small scale controlled tests, the Duck's curved cam-like body can stop 90% of wave motion and can convert 90% of that to electricity giving 81% efficiency.<ref>{{cite web|url=http://www.mech.ed.ac.uk/research/wavepower/EWPP%20archive/duck%20efficiency%20&%20survival%20notes.pdf|format=PDF|title=Edinburgh Wave Energy Project|publisher=[[University of Edinburgh]]|accessdate=2008-10-22}}</ref>
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| In the 1980s, as the oil price went down, wave-energy funding was drastically reduced. Nevertheless, a few first-generation prototypes were tested at sea. More recently, following the issue of climate change, there is again a growing interest worldwide for renewable energy, including wave energy.<ref name=falnes2007>{{cite journal |author=Falnes, J. |year=2007 |title=A review of wave-energy extraction |journal=Marine Structures |volume=20 |issue=4 |pages=185–201 |doi=10.1016/j.marstruc.2007.09.001}}</ref>
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| ==Modern technology==
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| Wave power devices are generally categorized by the '''method''' used to capture the energy of the waves, by '''location''' and by the '''power take-off system'''. Method types are point absorber or buoy; surfacing following or [[Wiktionary:attenuate|attenuator]] oriented parallel to the direction of wave propagation; terminator, oriented perpendicular to the direction of wave propagation; oscillating water column; and overtopping. Locations are shoreline, nearshore and offshore. Types of power take-off include: [[hydraulic ram]], [[Peristaltic pump|elastomeric hose pump]], pump-to-shore, [[Hydroelectricity|hydroelectric turbine]], air turbine,<ref>[http://web.archive.org/web/20060523114110/http://classes.engr.oregonstate.edu/eecs/fall2003/ece441/groups/g12/White_Papers/Kelly.htm Embedded Shoreline Devices and Uses as Power Generation Sources] ''Kimball, Kelly, November 2003</ref> and [[Linear motor|linear electrical generator]]. Some of these designs incorporate [[parabolic reflector]]s as a means of increasing the wave energy at the point of capture. These capture systems use the rise and fall motion of waves to capture energy.<ref name="Renewable Sea Power">McCormick, Michael E., and R. Cengiz Ertekin. Mechanical Engineering-CIME 131.5 (2009): 36. Expanded Academic ASAP. Web. October 5, 2009.</ref> Once the wave energy is captured at a wave source, power must be carried to the point of use or to a connection to the [[electrical grid]] by [[Electric power transmission|transmission]] [[submarine power cable|power cables]].<ref name=nyt20100316>
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| [http://www.nytimes.com/2010/03/17/business/energy-environment/17power.html Underwater Cable an Alternative to Electrical Towers], Matthew L. Wald, ''[[New York Times]]'', 2010-03-16. Retrieved 2010-03-18.</ref> The table contains descriptions of some wave power systems:
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| {|class="sortable wikitable" style="text-align:center;font-size: 9pt"
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| !|Device
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| ! style="width:75px;"| Proponent
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| ! style="width:75px;"| Country of origin
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| !width="75"|Capture method
| |
| !width="75"|Location
| |
| !width="75"|Power take off
| |
| !width="40"|Year build
| |
| ! style="width:500px;"|Notes
| |
| | |
| |-
| |
| |Anaconda Wave Energy Converter
| |
| |Checkmate SeaEnergy.[25]
| |
| |UK
| |
| |Surface-following attenuator
| |
| |Offshore
| |
| |Hydroelectric turbine
| |
| |2008
| |
| |align=left|In the early stages of development, the device is a {{convert|200|m|ft}} long rubber tube which is tethered underwater. Passing waves will instigate a wave inside the tube, which will then propagates down its walls, driving a turbine at the far end.<ref>[http://www.sciencedaily.com/releases/2008/07/080703101329.htm Anaconda WEC]. ''Science Daily'' (July 7, 2008).</ref><ref>[http://www.physics.org/featuredetail.asp?NewsId=27 Article about Anaconda on]. Physics.org.</ref>
| |
| |-
| |
| |AquaBuOY
| |
| |[[Finavera Wind Energy]], later SSE Renewables Limited
| |
| |Ireland-Canada-Scotland
| |
| |Buoy
| |
| |Offshore
| |
| |Hydroelectric turbine
| |
| |2003
| |
| |align=left|In 2009 Finavera Renewables surrendered its wave energy permits from FERC.[27] In July 2010 Finavera announced that it had entered into a definitive agreement to sell all assets and intellectual property related to the AquaBuOY wave energy technology.<ref>[http://www.sustainablebusiness.com/index.cfm/go/news.display/id/20617 Sustainable Business.com Finavera Renewables To Sell Ocean Energy Division]. Sustainablebusiness.com.</ref><ref>[http://www.stockmarketsreview.com/news/19202/ Stock Markets Review Finavera Renewables To Sell Finavera Renewables Ocean Energy – Quick Facts]. Stockmarketsreview.com (July 2, 2010).</ref><ref>[http://www.finavera.com/files/2010-07-02%20Finavera%20Renewables%20announces%20sale%20of%20Ocean%20Energy%20division.pdf Announcement of definitive agreement for sale of Finavera Ocean Energy Limited] {{Dead link|date=April 2012|bot=BlevintronBot}}</ref><ref>[http://www.wave-tidal-energy.com/home/news-archive/35-wave-projects/155-finavera-to-surrender-wave-energy-permits "Finavera To Surrender Wave Energy Permits"]</ref>
| |
| |-
| |
| |AWS-iii
| |
| |AWS Ocean Energy
| |
| |UK (Scotland)
| |
| |Surface-following attenuator?
| |
| |Offshore
| |
| |Air turbine
| |
| |2010
| |
| |align=left|The AWS-III is a floating toroidal vessel. It has rubber membranes on the outer faces which deform as waves pass, moving air inside chambers which in turn drive air-turbines to generate electricity. AWS Ocean tested a 1/9 scale model in Loch Ness in 2010, and are now working on a full sized version which will be 60m across and should generate 2.5 MW. It is envisage these will be installed in offshore farms moored in around 100m depth of water.<ref>{{cite web|title=Wave device tested on Loch Ness|url=http://news.bbc.co.uk/1/hi/scotland/highlands_and_islands/8692779.stm|publisher=BBC News|accessdate=17 November 2012}}</ref><ref>{{cite web|title=Cromarty Firth test for Jumbo wings-sized wave device|url=http://www.bbc.co.uk/news/uk-scotland-highlands-islands-11039065|publisher=BBC News|accessdate=17 November 2012}}</ref><ref>{{cite web|title=AWS Ocean Energy - AWS-III The story so far…|url=http://www.youtube.com/watch?v=hip6lu-q6FA|publisher=AWS Ocean|accessdate=17 November 2012}}</ref><ref>{{cite web|title=AWS Technology|url=http://www.awsocean.com/technology.aspx?ln=1|publisher=AWS Ocean|accessdate=17 November 2012}}</ref>
| |
| |-
| |
| |[[CETO Wave Power]]
| |
| |Carnegie
| |
| |Australia
| |
| |Buoy
| |
| |Offshore
| |
| |Pump-to-shore
| |
| |1999
| |
| |align=left|As of 2008, the device is being tested off Fremantle, Western Australia,[35] the device consists of a single piston pump attached to the sea floor with a float (buoy) tethered to the piston. Waves cause the float to rise and fall, generating pressurized water, which is piped to an onshore facility to drive hydraulic generators or run reverse osmosis water desalination.<ref>{{cite web|url=http://www.carnegiecorp.com.au/index.php?url=/ceto/ceto-overview|title=CETO Overview|publisher=carnegiecorp.com.au|accessdate=2008-11-03}}</ref><ref>{{cite news| title=New wave of power in renewable energy market| author=Stephen Cauchi| date=October 5, 2008| work=[[The Age (newspaper)|The Age]]| url= http://www.theage.com.au/national/new-wave-of-power-in-renewable-energy-market-20081004-4tyd.html| accessdate=2008-10-10 | location=Melbourne}}</ref>
| |
| |-
| |
| |[[Cycloidal Wave Energy Converter]]
| |
| |Atargis Energy Corporation
| |
| |USA
| |
| |Fully Submerged Wave Termination Device
| |
| |Offshore
| |
| |Direct Drive Generator
| |
| |2006
| |
| |align=left|In the tank testing stage of development, the device is a {{convert|20|m|ft}} diameter fully submerged rotor with two hydrofoils. Numerical studies have shown greater than 99% wave power termination capabilities.<ref>[http://dx.doi.org/10.1016/j.apor.2011.01.004 Applied Ocean Research: ] ''Deep ocean wave energy conversion using a cycloidal turbine'' (April, 2011).</ref> These were confirmed by experiments in a small 2D wave flume<ref>[http://dx.doi.org/10.1016/j.apor.2012.07.003 Applied Ocean Research: ] ''Experimental wave termination in a 2D wave tunnel using a cycloidal wave energy converter'' (April, 2012)</ref> as well as a large offshore wave basin.
| |
| |-
| |
| |FlanSea (Flanders Electricity from the Sea)
| |
| |FlanSea
| |
| |Belgium
| |
| |Buoy
| |
| |Offshore
| |
| |Hydroelectric turbine
| |
| |2010
| |
| |align=left|A point absorber buoy developed for use in the southern North Sea conditions.[31][32][33] It works by means of a cable that due to the bobbing effect of the buoy, generates electricity.<ref>[http://www.vliz.be/imis/imis.php?module=person&persid=138 FlanSea "optimal for use in southern North Sea"]. Vliz.be.</ref><ref>[http://kw.rnews.be/nl/regio/wvl/nieuws/algemeen/haven-oostende-en-universiteit-gent-willen-energie-winnen-uit-golven/article-1194880809025.htm Image of FlanSea]. Kw.rnews.be (December 1, 2010).</ref><ref>[http://www.deme.be/Press/press_item.asp?iId=183 FlanSea project page]. Deme.be (December 1, 2010).</ref>
| |
| |-
| |
| |Islay LIMPET
| |
| |[[Islay LIMPET]]
| |
| |Scotland
| |
| |oscillating water column
| |
| |Onshore
| |
| |Air turbine
| |
| |1991
| |
| |align=left|500 kW shoreline device uses an oscillating water column to drive air in and out of a pressure chamber through a [[Wells turbine]].<ref>{{cite news| url=http://news.bbc.co.uk/2/hi/science/nature/1032148.stm |work=BBC News | title=How it works: Wave power station | date=November 20, 2000}}</ref><ref>{{cite news| url=http://www.guardian.co.uk/environment/2000/sep/14/energy.renewableenergy | location=London |work=The Guardian | first=Gerard | last=Seenan | title=Islay pioneers harnessing of wave power | date=September 14, 2000}}</ref><ref>[http://www.waterpowermagazine.com/story.asp?storyCode=2048366 International Water Power and Dam Construction]. Waterpowermagazine.com (January 16, 2008).</ref>
| |
| |-
| |
| |[[Lysekil Project]]
| |
| |[[Uppsala University]]
| |
| |Sweden
| |
| |Buoy
| |
| |Offshore
| |
| |Linear generator
| |
| |2002
| |
| |align=left| Direct driven linear generator placed on the seabed, connected to a buoy at the surface via a line. The movements of the buoy will drive the translator in the generator.<ref name="Lei">{{cite web |url=http://www.springerlink.com/content/8634116882r00t13/fulltext.pdf |title=Wave Energy from the North Sea: Experiences from the lysekil Research site |accessdate=June 24, 2009 |author=Leijon, Mats et. al |date=April 9, 2008 }}</ref><ref name="Mat">{{cite journal |author=Leijon, Mats et. al |title=Catch the Wave to Electricity |journal=IEEE power energy magazine |date=January/February 2009 |pages=50–54 |accessdate=June 29, 2009 |url=http://ieeexplore.ieee.org/search/searchresult.jsp?SortField=Score&SortOrder=desc&ResultCount=25&maxdoc=100&coll1=ieeejrns&coll2=ieejrns&coll3=ieeecnfs&coll4=ieecnfs&coll5=ieeestds&coll6=preprint&coll7=books&coll8=modules&coll9=aip&srchres=0&history=yes&queryText=((Catch+the+wave+to+electricity)%3CIN%3Emetadata)&oldqrytext=((the+conversion+of+wave+motions+to+electricity)%3Cin%3Emetadata)&imageField.x=0&imageField.y=0&imageField=((the+conversion+of+wave+motions+to+electricity)%3Cin%3Emetadata)&radiobutton=cit |issue=1 |doi=10.1109/MPE.2008.930658 |volume=7 }}</ref>
| |
| |-
| |
| |[[Oceanlinx]]
| |
| |Oceanlinx
| |
| |Australia
| |
| |OWC
| |
| |Nearshore & Offshore
| |
| |air turbine
| |
| |1997
| |
| |align=left| Wave energy is captured with an [[Oscillating Water Column]] and electricity is generated by air flowing through a turbine. The third medium scale demonstration unit near Port Kembla, NSW, Australia, a medium scale system that was grid connected in early 2010.<ref name=spectrum200910>
| |
| {{cite news
| |
| | last = Adee
| |
| | first = Sally
| |
| | title = This Renewable Energy Source Is Swell
| |
| | publisher = [[IEEE Spectrum]] Inside Technology
| |
| | date = October 21, 2009
| |
| | url = http://spectrum.ieee.org/energy/renewables/this-renewable-energy-source-is-swell
| |
| | accessdate = 2009-10-22}}</ref>
| |
| In May 2010, the wave energy generator snapped from its mooring lines in extreme seas and sank on Port Kembla's eastern [[breakwater (structure)|breakwater]].<ref>{{Cite news
| |
| | title = Oceanlinx told to {{sic|clean|-up|nolink=y}} sunken energy generator
| |
| | accessdate = 2012-08-28
| |
| | publisher = ABC News
| |
| | date = May 25, 2010
| |
| | url = http://www.abc.net.au/news/2010-05-25/oceanlinx-told-to-clean-up-sunken-energy-generator/839928
| |
| }}</ref>
| |
| | |
| A full scale commercial nearshore unit, ''greenWAVE'', with a capacity of 1MW will be installed off [[Port MacDonnell]] in South Australia before the end of 2013.<ref name='ARENA'>{{cite web|title=Oceanlinx 1MW Commercial Wave Energy Demonstrator|url=http://arena.gov.au/project/oceanlinx-1mw-commercial-wave-energy-demonstrator/|work=ARENA|accessdate=27 November 2013}}</ref>
| |
| |-
| |
| |[[OE buoy]]
| |
| |Ocean Energy
| |
| |Ireland
| |
| |Buoy
| |
| |Offshore
| |
| |Air turbine
| |
| |2006
| |
| |align=left| In September 2009 completed a 2-year sea trial in one quarter scale form. The OE buoy has only one moving part.<ref>[http://www.oceanenergy.ie/oe-technology/platform.html Ocean Energy press release]. Oceanenergy.ie.</ref>
| |
| |-
| |
| |OWEL
| |
| |Ocean Wave Energy Ltd
| |
| |UK
| |
| |Wave Surge Convertor
| |
| |Offshore
| |
| |Air turbine
| |
| |2013
| |
| |align=left|The surging motion of long period waves compresses air in a tapered duct which is then used to drive an air turbine mounted on top of the floating vessel.<ref>{{cite web|title=The Technology|url=http://www.owel.co.uk/owel-technology/|publisher=Ocean Wave Energy Ltd|accessdate=25 January 2014}}</ref> The design of a full scale demonstration project was completed in Spring 2013, ready for fabrication.<ref>{{cite web|title=Completion of OWEL Marine Demonstrator design|url=http://www.owel.co.uk/2013/05/05/completion-of-owel-marine-demonstrator-design/|accessdate=25 January 2014|date=5 May 2013}}</ref>
| |
| |-
| |
| |[[Oyster wave energy converter]]
| |
| |Aquamarine Power
| |
| |UK (Scots-Irish)
| |
| |Oscillating wave surge converter
| |
| |Nearshore
| |
| |Pump-to-shore (hydro-electric turbine)
| |
| |2005
| |
| |align=left|A hinged mechanical flap attached to the seabed captures the energy of nearshore waves. It drives hydraulic pistons to deliver high pressure water to an onshore turbine which generates electricity. In November 2009, the first full-scale demonstrator Oyster began producing power on Orkney.<ref>{{cite web|title=Wave energy's new pearl: University begins testing Oyster tech off Scottish coast|url=http://www.zdnet.com/blog/green/wave-energys-new-pearl-university-begins-testing-oyster-tech-off-scottish-coast/9576|author=Heather Clancy|date=December 30, 2009|work=[[ZDNet]]|accessdate=2010-11-13}}</ref>
| |
| |-
| |
| |[[Pelamis Wave Energy Converter]]
| |
| |[[Pelamis Wave Power]]
| |
| |UK (Scottish)
| |
| |Surface-following attenuator
| |
| |Offshore
| |
| |Hydraulic
| |
| |1998
| |
| |align=left|As waves pass along a series of semi-submerged cylindrical sections linked by hinged joints, the sections move relative to one another. This motion activates [[hydraulic cylinder]]s which pump high pressure oil through [[Hydraulic machinery|hydraulic motors]] which drive [[electrical generator]]s.<ref>{{cite news | title=If Portugal can rule the waves, why not Scotland? | date=September 24, 2008 | author=Jenny Haworth |work=The Scotsman | accessdate=2008-10-09 | url=http://news.scotsman.com/opinion/If-Portugal-can-rule-the.4520629.jp | location=Edinburgh}}</ref> The first working Pelamis machine in 2004 was at the European Marine Energy Center.<ref>{{cite web|title=Update on EMEC activities, resource description, and characterisation of wave-induced velocities in a tidal flow|url=http://www.emec.org.uk/EWTEC7_EMEC.pdf'|accessdate=2010-12-03}}</ref> The later P2, owned by [[E.ON]], started grid connected tests off Orkney in 2010.<ref>{{cite web|title=Making Waves|url=http://www.scotland.gov.uk/News/Releases/2010/05/17144639|work=[[Scottish Government]]|accessdate=2011-04-07}}</ref>
| |
| | |
| |-
| |
| |[[PowerBuoy]]
| |
| |[[Ocean Power Technologies]]
| |
| |US
| |
| |Buoy
| |
| |Offshore
| |
| |Hydroelectric turbine
| |
| |1997
| |
| |align=left|The Pacific Northwest Generating Cooperative is funding construction of a commercial wave-power park at [[Reedsport, Oregon]] using buoys.<ref>{{cite web|url=http://www.renewableenergyaccess.com/rea/news/story?id=47546|title=Agreement to Develop Wave Power Park in Oregon|publisher=renewableeneregyaccess.com|accessdate=2008-10-15}}</ref> The rise and fall of the waves moves a [[rack and pinion]] within the buoy and spins a generator.<ref>{{cite news|title=Project Aims to Harness the Power of Waves|last=Johnson|first=Kirk|work=New York Times|date=September 3, 2012|url=http://www.nytimes.com/2012/09/04/us/project-aims-to-harness-wave-energy-off-the-oregon-coast.html|accessdate=2012-09-03}}</ref> The electricity is transmitted by a submerged transmission line. The buoys are designed to be installed one to five miles (8 km) offshore in water 100 to 200 feet (60 m) deep.<ref>{{cite web|url=http://www.mediafire.com/?sharekey=9a0349b792f8b2c25bf1f12f1ff3f30a07d42b6bc27c364ef1940a51b339e393|title=Reedsport OPT Wave Park FERC Project No. 12713 Application for a Major License|publisher=Federal Energy Regulatory Commission|accessdate=2010-02-15}}</ref>
| |
| | |
| [[File:Optbuoy.jpg|thumb|center|PB150 [[PowerBuoy]] with peak-rated power output of 150 kW.]]
| |
| |-
| |
| |R38/50 kW, R115/150 kW
| |
| |40South Energy
| |
| |UK
| |
| |Underwater attenuator
| |
| |Offshore
| |
| |Electrical conversion
| |
| |2010
| |
| |align=left|These machines work by extracting energy from the relative motion between one Upper Member and one Lower Member, following an innovative method which earned the company one UKTI Research & Development Award in 2011.<ref>{{cite web | url=http://www.ukti.gov.uk/uktihome/news/124686.html | title=40South Energy assigned the 2011 UKTI Italy Research & Development Award| date=February 3, 2011}}</ref> A first generation full scale prototype for this solution was tested offshore in 2010,<ref>{{cite web | url=http://www.40southenergy.com/2010/08/installation-of-d100t/ | title=40South Energy installs at sea the D100t full scale prototype| date=August 12, 2010}}</ref><ref>{{cite web | url=http://www.energyengineering.co.uk/archive/index.html | title=High achiever, Energy Engineering Magazine, Issue 33, page 51| author=Theone Wilson| year=2011}}</ref><ref>{{cite web | url=http://www.renews.biz | title=ReNews, Issue 198, page 15| date=26 August 201}}</ref> and a second generation full scale prototype was tested offshore during 2011.<ref>{{cite web | url=http://www.40southenergy.com/2011/05/y25t-in-operation/ | title=40South Energy puts in operation the Y25t full scale prototype| date=August 12, 2010}}</ref> In 2012 the first units were sold to clients in various countries, for delivery within the year.<ref>{{cite web | url=http://www.renews.biz | title=Real deal shapes up in Italy for 40South Energy, reNews, Issue 224, page 3| date=September 29, 2011}}</ref><ref>{{cite web | url=http://www.decc.gov.uk/en/content/cms/regional_news/london/london.aspx| title=40South Energy: preliminary agreement with two Italian developers for sale of machines, DECC REgional news: London}}</ref> The first reduced scale prototypes were tested offshore during 2007, but the company decided to remain in a "stealth mode" until May 2010<ref>{{cite web | url=http://www.siemens.co.uk/events/pool/home/EFEF/thefutureofenergy.pdf | title=Charging beneath the sea, Daily Telegraph Supplement, The Future of Energy| date=October 2010}}</ref> and is now recognized as one of the technological innovators in the sector.<ref>{{cite web | url=http://www.gbreports.com/admin/reports/Energy_Handbook2011.pdf| title=Energy Handbook 2011| author= Joseph Hincks| year=2011}}</ref> The company initially considered installing at Wave Hub in 2012,<ref>{{cite web | url=http://www.renews.biz | title=Italian wants front seat at Wave Hub, ReNews, Issue 195, page 2| date=July 1, 2010}}</ref> but that project is on hold for now. The R38/50 kW is rated at 50 kW while the R115/150 kW is rated at 150 kW.
| |
| |-
| |
| |[[SDE Sea Waves Power Plant]]
| |
| |SDE Energy Ltd.
| |
| |Israel
| |
| |Buoy
| |
| |Nearshore
| |
| |Hydroelectric turbine
| |
| |2010
| |
| |align=left| A breakwater-based wave energy converter, this device is built close to the shore and utilizes the vertical motion of buoys for creating hydraulic pressure which in turn operates the system's generators. In 2010 it began construction of a new 250 kWh model in the port of Jaffa, Tel Aviv and preparing to construct its standing orders for a 100 MWh power plants in the islands of Zanzibar and Kosrae, Micronesia.
| |
| |-
| |
| |SeaRaser
| |
| |Alvin Smith (Dartmouth Wave Energy)\[[Ecotricity]]
| |
| |UK
| |
| |Buoy
| |
| |Nearshore
| |
| |Hydraulic ram
| |
| |2008
| |
| |align=left|Consisting of a piston pump(s) attached to the sea floor with a float (buoy) tethered to the piston. Waves cause the float to rise and fall, generating pressurized water, which is piped to resoviors onshore which then drive hydraulic generators.<ref>{{cite news|url=http://www.timesonline.co.uk/tol/news/environment/article5167812.ece|title=Searaser device in uphill battle for clean energy|author=Lewis Smith|date=November 17, 2008|work=The Sunday Times|accessdate=2010-11-13|location=London}}</ref><ref>{{cite news| url=http://www.bbc.co.uk/news/uk-england-devon-16676818 |work=BBC News | title=Plans for sea energy device Searaser | date=January 23, 2012}}</ref>
| |
| It is currently "undergoing extensive modelling ahead of a sea trial" <ref>http://zerocarbonista.com/2012/12/04/monopoly-money/#more-3561</ref>
| |
| |-
| |
| |Squid/ WaveNET
| |
| |AlbaTERN
| |
| |UK (Scotland)
| |
| |Multi-point absorber
| |
| |Nearshore
| |
| |Hydraulic?
| |
| |2011
| |
| |align=left|A 10 kW Squid prototype was tested at [[EMEC]] in 2011.<ref>{{cite news|last=Shankleman|first=Jessica|title=Squid-like device aims to harness power of Scottish waves|url=http://www.businessgreen.com/bg/news/2071865/squid-device-aims-harness-power-scottish-waves|accessdate=25 January 2014|newspaper=BusinessGreen|date=18 May 2011}}</ref> The company have since secured funding through the WATERS2 project, to further develop the device including developing arrays.<ref>{{cite web|title=AlbaTERN secures £617,000 of WATERS 2 support for their first WaveNET demonstrator array|url=http://albatern.co.uk/albatern-secures-617000-of-waters-2-support-for-their-first-wavenet-demonstrator-array/|publisher=AlbaTERN|accessdate=25 January 2014|date=29 August 2012}}</ref>
| |
| |-
| |
| |Unnamed Ocean Wave-Powered Generator
| |
| |SRI International
| |
| |US
| |
| |Buoy
| |
| |Offshore
| |
| |[[Electroactive polymers|Electroactive polymer]] artificial muscle
| |
| |2004
| |
| |align=left|A type of wave buoys, built using special polymers, is being developed by SRI International.<ref>{{cite pressrelease|url=http://www.sri.com/newsroom/press-releases/sri-demonstrates-ocean-wave-powered-generator-california-coast|title=SRI Demonstrates Ocean Wave-Powered Generator off California Coast|publisher=[[SRI International]]|date=2008-08-12|accessdate=2013-07-10}}</ref><ref>{{cite news| title=Researchers wring energy out of ocean waves | date=December 14, 2008 | author=Carolyn Said | accessdate=November 9, 2010 | url=http://articles.sfgate.com/2008-12-14/business/17131881_1_ocean-energy-roger-bedard-sri-technology |work=San Francisco Chronicle }}</ref>
| |
| |-
| |
| |[[Wavebob]]
| |
| |Wavebob
| |
| |Ireland
| |
| |Buoy
| |
| |Offshore
| |
| |Direct Drive Power Take off
| |
| |1999
| |
| |align=left|Wavebob have conducted some ocean trials, as well as extensive tank tests. It is an ocean-going heaving buoy, with a submerged tank which captures additional mass of seawater for added power and tunability, and as a safety feature (Tank "Venting")
| |
| | |
| |-
| |
| |[[Wave Dragon]]
| |
| |Erik Friis-Madsen
| |
| |Denmark
| |
| |Overtopping device
| |
| |Offshore
| |
| |Hydroelectric turbine
| |
| |2003
| |
| |align=left| With the Wave Dragon wave energy converter large wing reflectors focus waves up a ramp into an offshore reservoir. The water returns to the ocean by the force of gravity via hydroelectric generators.
| |
| | |
| [[File:WaveDragon.JPG|thumb|center|Wave Dragon seen from reflector, prototype 1:4½]]
| |
| |-
| |
| |WaveRoller
| |
| |AW-Energy Oy
| |
| |Finland
| |
| |Oscillating wave surge converter
| |
| |Nearshore
| |
| |Hydraulic
| |
| |1994
| |
| |align=left|The WaveRoller is a plate anchored on the sea bottom by its lower part. The back and forth movement of surge moves the plate. The kinetic energy transferred to this plate is collected by a piston pump. Full-scale demonstration project built off Portugal in 2009.<ref>{{cite web | url=http://www.scientificamerican.com/article.cfm?id=waveroller-uses-swinging-door-for-u-2009-11 | title=WaveRoller uses swinging door for underwater wave energy | author=Susan Kraemer | publisher=Scientific American | date=November 3, 2009 | accessdate=December 9, 2010 }}</ref><ref>[http://www.aw-energy.com/index.html AW-Energy Oy]. Aw-energy.com.</ref>
| |
| | |
| [[File:WaveRoller wave energy farm installation in Peniche, Portugal 2012.JPG|thumb|center|WaveRoller farm installation in Peniche, Portugal. August 2012]]
| |
| |-
| |
| |Wave Star
| |
| |Wave Star A/S
| |
| |Denmark
| |
| |Multi-point absorber
| |
| |Offshore
| |
| |Hydroelectric turbine
| |
| |2000
| |
| |align=left|The Wavestar machine draws energy from wave power with floats that rise and fall with the up and down motion of waves. The floats are attached by arms to a platform that stands on legs secured to the sea floor. The motion of the floats is transferred via hydraulics into the rotation of a generator, producing electricity. Wave Star has been testing a 1:10 machine since 2005 in Nissum Bredning, Denmark, it was taken out of duty in November 2011. A 1:2 Wave Star machine is in place in [[Hanstholm]] which has produced electricity to the grid since September 2009.<ref>{{cite web | url=http://www.cleanindex.net/startups/article/danish-wavestar-energy-retires-company-s-old-test-plant-and-plans-ten-fold | title=Danish WaveStar Energy retires the company’s old test plant – and plans a ten-fold expansion of the full-scale wave power plant | author=Mats Renvall | date=November 27, 2011 | accessdate=2012-01-05}}</ref>
| |
| |}
| |
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| ==Potential==
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| The worldwide resource of wave energy has been estimated to be greater than 2 TW.<ref>{{Cite book| title=Green Energy and Technology, Ocean Wave Energy| author=Cruz J.|coauthors=Gunnar M., Barstow S., Mollison D.| editor=Joao Cruz| publisher=[[Springer Science+Business Media]]| year=2008| isbn=978-3-540-74894-6|page=93}}</ref>
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| Locations with the most potential for wave power include the western seaboard of Europe, the northern coast of the UK, and the Pacific coastlines of North and South America, Southern Africa, Australia, and New Zealand. The north and south [[temperate zones]] have the best sites for capturing wave power. The prevailing [[westerlies]] in these zones blow strongest in winter.
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| ==Challenges==
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| There is a potential impact on the marine environment. Noise pollution, for example, could have negative impact if not monitored, although the noise and visible impact of each design varies greatly.<ref name="ocs"/> Other biophysical impacts (flora and fauna, sediment regimes and water column structure and flows) of scaling up the technology is being studied.<ref>[http://www.nerc.ac.uk/research/programmes/mre/background.asp Marine Renewable Energy Programme], [[Natural Environment Research Council|NERC]] Retrieved 2011-08-01</ref> In terms of socio-economic challenges, wave farms can result in the displacement of commercial and recreational fishermen from productive fishing grounds, can change the pattern of beach sand nourishment, and may represent hazards to safe navigation.<ref>[[Steven Hackett]]:''Economic and Social Considerations for Wave Energy Development in California'' [http://www.energy.ca.gov/2008publications/CEC-500-2008-083/CEC-500-2008-083.PDF CEC Report Nov 2008] Ch2, pp22-44 [[California Energy Commission]]|Retrieved 2008-12-14</ref> Waves generate about 2,700 gigawatts of power. Of those 2,700 gigawatts, only about 500 gigawatts can be captured with the current technology.<ref name="Renewable Sea Power">[http://find.galegroup.com "Renewable sea power: waves, tides, and thermals—new research funding seeks to put them to work for us."] McCormick, Michael E., and R. Cengiz Ertekin. "Renewable sea power: waves, tides, and thermals—new research funding seeks to put them to work for us." Mechanical Engineering-CIME 131.5 (2009): 36. Expanded Academic ASAP. Web. October 5, 2009.</ref>
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| ==Wave farms==
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| {{Main|Wave farm}}
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| === Portugal ===
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| * The [[Aguçadoura Wave Farm]] was the world's first [[wave farm]]. It was located {{convert|5|km|mi|0|abbr=on}} offshore near '''[[Póvoa de Varzim]]''', north of [[Porto]], Portugal. The farm was designed to use three [[Pelamis wave energy converter|Pelamis]] wave energy converters to convert the motion of the [[ocean surface wave]]s into electricity, totalling to {{nowrap|2.25 [[Megawatt|MW]]}} in total installed capacity. The farm first generated electricity in July 2008<ref>{{cite web|title=First Electricity Generation in Portugal|url=http://www.pelamiswave.com/news?archive=1&mm=7&yy=2008}}</ref> and was officially opened on September 23, 2008, by the Portuguese Minister of Economy.<ref name="gov.pt">{{cite web|title=23 de Setembro de 2008|url=http://www.portugal.gov.pt/portal/pt/comunicacao/agenda/20080923.htm|publisher=[[Government of Portugal]]|accessdate=2008-09-24}}</ref><ref>{{cite news | title=Making waves: UK firm harnesses power of the sea ... in Portugal | url=http://www.guardian.co.uk/technology/2008/sep/25/greentech.alternativeenergy |work=The Guardian | accessdate=2008-10-09 | location=London | first=Alok | last=Jha | date=September 25, 2008}}</ref> The wave farm was shut down two months after the official opening in November 2008 as a result of the financial collapse of Babcock & Brown due to the global economic crisis. The machines were off-site at this time due to technical problems, and although resolved have not returned to site and were subsequently scrapped in 2011 as the technology had moved on to the P2 variant as supplied to Eon and Scottish Power Renewables.<ref name="Pelamis Sinks">{{cite web|title=Pelamis Sinks Portugal Wave Power|url=http://cleantech.com/news/4276/pelamis-sinks-portugal-wave-power-p|publisher=[[cleantech.com]]|accessdate=2009}}</ref> A second phase of the project planned to increase the installed capacity to {{nowrap|21 MW}} using a further 25 Pelamis machines<ref>{{cite news|title=Babcock, EDP and Efacec to Collaborate on Wave Energy Projects|author=Joao Lima|url=http://www.bloomberg.com/apps/news?pid=20601081&sid=aSsaOB9qbiKE&refer=australia|publisher=[[Bloomberg Television]]|accessdate=2008-09-24|date=September 23, 2008}}</ref> is in doubt following Babcock's financial collapse.
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| === United Kingdom ===
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| * Funding for a {{nowrap|3 MW}} wave farm in '''Scotland''' was announced on February 20, 2007, by the [[Scottish Executive]], at a cost of over 4 million [[pound sterling|pounds]], as part of a £13 million funding package for [[Renewable energy in Scotland#Wave power|marine power in Scotland]]. The first of 66 machines was launched in May 2010.<ref>{{cite news | author = Fyall, Jenny | title = 600ft 'sea snake' to harness power of Scotland |work=The Scotsman | date = May 19, 2010 | pages = 10–11 | url = http://news.scotsman.com/scotland/600ft-39sea-snake39-to-harness.6303096.jp | accessdate = 2010-05-19 | location=Edinburgh}}</ref>
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| * A facility known as [[Wave hub]] has been constructed off the north coast of Cornwall, England, to facilitate wave energy development. The Wave hub will act as giant extension cable, allowing arrays of wave energy generating devices to be connected to the electricity grid. The Wave hub will initially allow {{nowrap|20 MW}} of capacity to be connected, with potential expansion to {{nowrap|40 MW}}. Four device manufacturers have so far expressed interest in connecting to the Wave hub.<ref>{{cite news | title=Wave farm wins £21.5m grant |work=The Guardian | date=April 26, 2007 | author=James Sturcke | url=http://www.guardian.co.uk/environment/2007/apr/26/energy.uknews | accessdate=2009-04-08 | location=London}}</ref><ref>{{cite news | title=Tender problems delaying Wave Hub |publisher=BBC News | date=April 2, 2008 | url=http://news.bbc.co.uk/2/hi/uk_news/england/cornwall/7326971.stm | accessdate=2009-04-08 }}</ref> The scientists have calculated that wave energy gathered at Wave Hub will be enough to power up to 7,500 households. The site has the potential to save greenhouse gas emissions of about 300,000 tons of carbon dioxide in the next 25 years.<ref>{{cite news|title=Go-ahead for £28m Cornish wave farm|url=http://www.guardian.co.uk/environment/2007/sep/17/renewableenergy.uknews|work=The Guardian|accessdate=2008-10-12 | location=London | date=September 17, 2007}}</ref>
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| === Australia ===
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| *A [[CETO Wave Power|CETO]] wave farm off the coast of '''[[Western Australia]]''' has been operating to prove commercial viability and, after preliminary environmental approval, is poised for further development.{{Citation needed|date=April 2009}}<ref>{{cite web | url=http://www.ceto.com.au/home.php | title=Renewable Power from the Ocean's Waves | publisher=[[CETO Wave Power]] | accessdate=November 9, 2010 }}</ref><ref>{{cite news | title=Wave of the future needs investment | author=Keith Orchison |work=The Australian | date=October 7, 2010 | accessdate=November 9, 2010 | url=http://www.theaustralian.com.au/special-reports/climate-change/climate-change/story-fn5oikwf-1225935586957 }}</ref>
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| * [[Ocean Power Technologies]] ([[OPT Australasia Pty Ltd]]) is developing a wave farm connected to the grid near '''[[Portland, Victoria]]''' through a 19 MW wave power station. The project has received an AU $66.46 million grant from the Federal Government of Australia.<ref name="Reeds12July2012">[http://afr.com/p/business/companies/lockheed_martin_woodside_in_wave_My0jdU2iFjWnsq4gT282EK/ Lockheed Martin, Woodside, Ocean Power Technologies in wave power project], Portland Victoria Wave Farm</ref>
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| *[[Oceanlinx]] will deploy a commercial scale demonstrator off the coast of South Australia at [[Port MacDonnell]] before the end of 2013. This device, the ''greenWAVE'', has a rated electrical capacity of 1MW. This project has been supported by ARENA through the Emerging Renewables Program. The ''greenWAVE'' device is a bottom standing gravity structure, that does not require anchoring or seabed preparation and with no moving parts below the surface of the water.<ref name="ARENA" />
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| === United States ===
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| * '''Reedsport, Oregon''' – a commercial wave park on the west coast of the United States located 2.5 miles offshore near [[Reedsport, Oregon]]. The first phase of this project is for ten PB150 [[PowerBuoy]]s, or 1.5 megawatts.<ref name="Reeds14Mar2012">[http://www.alternative-energy-news.info/technology/hydro/wave-power/ America’s Premiere Wave Power Farm Sets Sail], Reedsport Wave Farm</ref><ref name="Reeds03Oct2012">[http://www.forbes.com/sites/davidferris/2012/10/03/in-wave-energy-oregon-races-to-catch-up-to-europe/?ss=business:energy] US catching up with Europe - Forbes October 3, 2012</ref> The Reedsport wave farm was scheduled for installation spring 2013.<ref name="Reeds04102012">[http://www.oregonlive.com/pacific-northwest-news/index.ssf/2012/10/setback_arises_for_wave-power.html] Reedsport project delayed due to early onset of winter weather - OregonLive Oct 2012</ref> Project has ground to a halt because of legal and technical problems, August, 2013. See:-
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| http://www.oregonlive.com/environment/index.ssf/2013/08/oregon_wave_energy_stalls_off.html
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| ==Patents==
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| *{{US patent|3928967}} — 1974 ''Apparatus and method of extracting wave energy'' – The original "Salter's Duck" patent
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| *{{US patent|4134023}} — 1977 ''Apparatus for use in the extraction of energy from waves on water'' – Salter's method for improving "duck" efficiency
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| *{{US patent|6194815}} — 1999 ''Piezoelectric rotary electrical energy generator''
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| *{{US patent application|20040217597}}{{Dead link|date=August 2012}} — 2004 ''Wave energy converters utilizing pressure differences'' ([http://www.freepatentsonline.com/y2004/0217597.html src])
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| == See also ==
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| * [[Ocean thermal energy conversion]]
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| * [[World energy resources and consumption]]
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| {{subject bar|portal1=Renewable energy|portal2=Energy}}
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| ==Notes==
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| {{Reflist|group=lower-alpha}}
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| ==References==
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| {{Reflist|30em}}
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| ==Further reading==
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| *{{Cite book| title=Ocean Wave Energy – Current Status and Future Prospects| first=Joao| last=Cruz| publisher=Springer| year=2008| isbn=3-540-74894-6}}, 431 pp.
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| *{{Cite book| title=Ocean Waves and Oscillating Systems| first=Johannes| last=Falnes| publisher=Cambridge University Press| year=2002| isbn=0-521-01749-1}}, 288 pp.
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| *{{Cite book|title=Ocean Wave Energy Conversion| first=Michael| last=McCormick| publisher=Dover| year=2007| isbn=0-486-46245-5}}, 256 pp.
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| *{{Cite book| title=Renewable Energy Resources| first1=John| last1=Twidell| first2=Anthony D.| last2= Weir| first3=Tony| last3=Weir| publisher=Taylor & Francis| year=2006| isbn=0-419-25330-0}}, 601 pp.
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| ==External links==
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| {{Commons category|Wave power}}
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| {{Commons category|Renewable energy}}
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| * [http://www.uu.se/en/news/news-document/?id=1339&area=5,12,16&typ=artikel&na=&lang=en "Ocean waves – our new electricity supplier"] {{Wayback|date=20100107095548|url=http://www.uu.se/en/node1019|df=yes}} (Uppsala university 2010)
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| *{{cite news | title=Power From the Restless Sea Stirs the Imagination | author=Kate Galbraith | date=September 22, 2008 |work=New York Times | url=http://www.nytimes.com/2008/09/23/business/23tidal.html?em | accessdate=2008-10-09 }}
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| *[http://www.economist.com/search/displaystory.cfm?story_id=11482565 "Wave Power: The Coming Wave"] from the Economist, June 5, 2008
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| * [http://www.offshorewind.biz/2013/04/22/russian-company-develops-mobile-wave-energy-generator/ Russian Company Develops Mobile Wave Energy Generator]
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| *[http://www.greenleft.org.au/back/1992/64/64cenb.htm "The untimely death of Salter's Duck"]
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| *[http://www.technologyreview.com/Energy/14268/ "Ocean Power Fights Current Thinking"]
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| *[http://www.publicaddress.net/default,4132.sm "Wave energy in New Zealand"]
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| *[http://www.lorc.dk/Knowledge/Wave-energy/Wave-technologies Wave technologies: types of devices] (LORC Knowledge 2011)
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| *[http://news.bbc.co.uk/1/hi/sci/tech/1032148.stm "How it works: Wave power station"]
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| {{Ocean energy}}
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| {{physical oceanography}}
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| {{Natural resources}}
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| {{DEFAULTSORT:Wave Power}}
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| [[Category:Energy conversion]]
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| [[Category:Wave power| ]]
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| [[Category:Power station technology]]
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| [[Category:Sustainable technologies]]
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