Tidal power Science project.

Un bel giorno snipped-for-privacy@hotmail.com digitò:

Yes, someone did:

--
emboliaschizoide.splinder.com

Talk to someone who owns a boat that is used in saltwater. It is a very nasty environment. Even after using semi-exotic materials (e.g. stainless steel), there are high maintenance requirements.

If that's your only concern, use the tides in bodies of fresh water.

--
Keith

:I am just curious if anyone has thought about a float that is lifted :up against a ratchet and pawl to the highest point, then released at :the lowest point of the tide to fall at 1G. It seems, intuitively , :that the stored energyu/ impetus would give greater burstsof energy :from aDC motor, which could be stored in a supercap, then bled off :slowly to smooth out the oulse. Just noodling, I haven't had the time :to think it through, so I am tossing raw meat into the midst of the :pack and await enlightenment. ;>

:Kwiz

The CETO wave power system looks to be promising.

Mechanical ratchet and pawl systems are high maintenance and not suitable for long and reliable service imo.

A different way to implement the idea:

Imagine a tube pointing down into the water. As the water rises, the air trapped in the tube will be compressed. A check valve at the top of the tube directs this compressed air into a tank. As the water falls, the column of water creates a vacuum at the top of the tube. A check valve causes this vacuum to create a vacuum in a second tank. An air motor between the two tanks can provide an output.

promising.http://www.ceto.com.au/home.php

It will only be cycling a couple of times per day. Such things can be made to last for 100,000 cycles with careful design. 274 years is long enough.

The idea is dumb. The energy generated by float falling a few feet twice a day would never recover the energy use to construct it.

A 1000kg float falling 2m twice a day with 100% conversion efficiency would produce about 450mW. About enough to make one cup of tea every 3 days.

:On Feb 20, 9:55 pm, Ross Herbert wrote: :> On Wed, 20 Feb 2008 09:17:41 -0800, snipped-for-privacy@hotmail.com wrote: :>

:> :I am just curious if anyone has thought about a float that is lifted :> :up against a ratchet and pawl to the highest point, then released at :> :the lowest point of the tide to fall at 1G. It seems, intuitively , :> :that the stored energyu/ impetus would give greater burstsof energy :> :from aDC motor, which could be stored in a supercap, then bled off :> :slowly to smooth out the oulse. Just noodling, I haven't had the time :> :to think it through, so I am tossing raw meat into the midst of the :> :pack and await enlightenment. ;>

:> :Kwiz :>

:> The CETO wave power system looks to be promising.http://www.ceto.com.au/home.php :>

:> Mechanical ratchet and pawl systems are high maintenance and not suitable for :> long and reliable service imo. : : :It will only be cycling a couple of times per day. Such things can be :made to last for 100,000 cycles with careful design. 274 years is :long enough.

Aside from the mechanical reliability, about which you are probably correct, and going by the description in the OP's post, there would be only 2 energy generation periods per day, ie. whenever low tide occurred. If I choose a suitable location in my state where tides are roughly 8M http://161.152.28.103:10003/pls/lweb/cdc_tide_prediction I see that low tides generally occur when energy demand is not exactly at its peak. This method of energy generation would not be particularly efficient unless there was some way of storing the energy for later use to make it viable as a base power generation source.

CETO, on the other hand is continuous in action 24/7, relying upon simple wave action for its operation. As they say "many hands (pumps in this case) make light (no pun) work", thus making it suitable for a use as a base power generating source.

:Aside from the mechanical reliability, about which you are probably correct, and :going by the description in the OP's post, there would be only 2 energy :generation periods per day, ie. whenever low tide occurred. If I choose a :suitable location in my state where tides are roughly 8M :http://161.152.28.103:10003/pls/lweb/cdc_tide_prediction I see that low tides SNIP

Sorry, that link won't work directly I have found.

You will need to go here

and select BROOME and then in the next screen hit search to display the 7 day tidal data.

tides

Not a very high percentage of the earth's coastlines have tides anywhere near that high (it's caused by oceanic slop like in the corner of a square bucket), and mostly they aren't high population areas anyhow, as it's much harder to build port facilities.

The average neap tide is 0.5m, king tide is 1.5m, between high and low. Multiply that difference by the mass of your float and you have the maximum available energy. You'd need to cover several square kilometers of area with floating objects that could derive useful power from motion that has average twice-daily peaks of

0.07mm/second (0.26m/hour). It's just not viable.

Doing something with tidal flow in/out of a large estuary or bay, now that's a possibility. I even recall seeing a proposed scheme to dam the Mediterranean, which has a net inflow from the Atlantic, and use the drop to reclaim sea-front land and generate GW. It'll never happen though.

Clifford Heath.