Talk:Tidal power

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[edit] Talk Page Archive

Archive 2 has been created with a link at above right. It is an exact copy of the talk page as it was before this edit. Archive 3, when needed in the future, should be a new subpage (same as creating an article) titled "Talk:Tidal power/Archive3" and the link added to the template on this page's code. For further information on archiving see Wikipedia:How to archive a talk page. See also User:5Q5 for the used archiving procedure. Thank you. Crowsnest (talk) 11:41, 28 March 2008 (UTC)

[edit] Citations needed

With one exception the citations requested for the price calculations have already been provided, i.e. the price paid for renewable energy in remote areas can cost US$0.50-60 cents per kilo watt as turbines are run on diesel power that is transported long distances to the remote locations. This is common knoweledge in the industry. The dilemna arises as to which remote location to choose. Does ones choose a location in remote Canada or Australia? As for the other citations they have already been provided in the text of the main page i.e the citation requested for price calculations is developed from the power equation above on the main page, so therefore the evidence has already been provided, the citation for the shrouded turbine has been provided many many times here on this discussion page and has caused a mini war between some editors - please read the "Developments in Ducted Turbines" by Kirke, the run of river citation seems to indicate a lack of understanding of tidal stream and run of river as tidal stream is exactly that, tidal stream, harnessing the flow of the flood and ebb tide, however, a run of river is a system that uses the natural flow of a river which flows constantly in one direction 24 hours a day - run of river is therefore self explainatory, the citation requested for the revenue increasing 8 times when the velocity doubles arise from the power calculation already provided above on the main page - as velocity doubles the power output increases 8 times due to the velocity cubed element in the equation for example 2 x 2 x 2 = 8 but 4 x 4 x 4 = 64 ..... simple maths - therefore the revenue which is directly proportional to the power, will increase 8 fold for every doubling of the velocity - all these have been provided.Tidalenergy 08:52, 15 November 2007 (UTC)

[edit] Source of Tidal Energy

I note that the opening paragraph currently states that the source of tidal energy is the Moon. This is not quite correct. The source of tidal energy is actually the rotational energy of the Earth. If the Earth did not rotate with respect to the Moon, lunar tides would still exist but they would be static and thus it would be impossible to extract energy from them. On the other hand if the Earth rotated but the Moon did not exist, there would still be (much smaller) solar tides from which energy could be extracted. Thus there is a very definite limit to the amount of energy that can be extracted from tides. While that limit is large, it is quantifiable. The supply is definitely not inexhaustible and extracting too much of it will, sooner or later, lead to undesirable side effects such as 25 hour days (or even longer). Of course this is also happening naturally as our tidal acceleration article explains. -- Derek Ross | Talk 05:42, 5 December 2007 (UTC)

This is an important point. Not that harnessing tidal power will have a noticeable effect on the length of the day (it won't within the next few million years), but that the tidal energy source is very limited in practice, not just in principle as for solar/wind/nuclear. Whereas the world's electricity production is, apparently, currently ~5TW, the tidal energy source is about 3.7 TW, only a small fraction of which will ever realistically be converted to electricity. (Increasing drag using turbines will probably not significantly affect the total source, but, counterintuitively, it's at least as likely to reduce it as increase it.) I would have thought a more accurate description of the energy source, together with a note about the potential contribution to global energy needs, should feature prominently. -- Kicocolm (talk) 11:28, 10 December 2007 (UTC)
Check through the history of discussion on this page. It was mentioned a few times but due to war between editors it was deleted by a person who believed their opinion on tidal barrages was pre-eminent. Please feel free to try again. 210.9.237.1 (talk) 05:19, 16 December 2007 (UTC)
There seems to be a misinterpretation, here and elsewhere at WikiPedia, on the consequences of 3.7 TW tidal dissipation (see the link above to Munk & Wunsch, 1999), which is mixed up with a 3.7 TW tidal energy source. This would only be true in case of an equilibrium between dissipation and propulsion, e.g. a car driving at constant speed with a motor compensating for the energy dissipation. Since the Earth's rotational energy is the source of the fluctuating tides, there is no equilibrium (other than the case when one Earth day has lengthened to 28 days). There is only a tiny tidal dissipation which "will have a noticeable effect in millions of years". So, it is clear that the mentioned 3.7 TW is only a fraction of the available amount of tidal energy (in the order of EW, 1018 Watt). Kraaiennest (talk) 23:45, 12 February 2008 (UTC)
I agree that the source of tidal energy is not the moon but the earth's rotation. Tides involve no transfer of energy, kinetic, potential, or otherwise, from the moon to the earth. The moon, through its gravity, simply provides a mechanism for this rotational energy to be used at the earth's surface. This section should be changed unless there is an objection. Rudkins 17:05, 12 February 2008 (UTC) —Preceding unsigned comment added by Rudkins (talk • contribs)

[edit] Lots of tidal stream designs appearing

Just a quick note to the FIG to say your prejudiced opinion about tidal stream not being as common as you claimed can be checked on the Tidal Power page. Seems like your Severn Barrage will never see the light of day given all the money being invested in tidal stream technologies around the globe. See for yourself how many are being commercialised AND see the shrouded designs that you claimed didn't work. Sorry to say I was right about that old man. Tidalenergy (talk) 04:17, 22 March 2008 (UTC)

[edit] Types of Tidal turbines reverted

There are a number of shrouded turbines emergeing that may or may not have significance in the industry that need to find a place on the main page. Removal of the comparisons and contrasts make the page poorer for the exercise and limits the value of information. 210.9.237.1 (talk) 00:44, 24 March 2008 (UTC)Ю

[edit] Tidal stream or barrages layout corrected

If the Tidal Stream is the first heading then the fist dot point should be Tidal Stream not the other way round. 210.9.237.1 (talk) 04:46, 28 March 2008 (UTC)