Edited 6/6/06 with input from [jmvw] (see annos).
This system would utilize a pair of large, thin, flat bladders containing a Hydraulic Fluid (i.e. water). These bladders would be installed below the sand on a beach at a depth such that it will not be exposed during normal wave action. The bladders are connected with 2 small scale Turbine type generators. The interior of this bladder system would be filled with a very porous Foam material that would allow it to maintain its shape and return it to shape during each cycle.
The mechanism of operation would be that the incoming waves or tides would cause increased pressure on the beach, forcing liquid out of the upper Bladder through the Turbine to generate power. As the wave retreats the water would return to the lower bladder through a low restriction check valve thus resetting for the next wave(or Tide). Though power generated would be relatively small it would be sufficient to supply power to individual homes without the deleterious visual impact and complex mechanicals of many related systems.-- jhomrighaus, Jul 05 2006 Now THAT is a half baked idea. I like it.-- Galbinus_Caeli, Jul 05 2006 I have the feeling you just taught someone a lesson here.-- methinksnot, Jul 05 2006 Can I bun it even if *I* don't really understand how it works? ....OK, I did.-- xandram, Jul 05 2006 Its a sub sand whoopee cushion filled with water, with a generator replaciing the brrraaaatulator.-- Galbinus_Caeli, Jul 05 2006 would foot traffic boost power generation?-- bleh, Jul 05 2006 Why have a bladder here at all? Why not just toss the turbine in the sea? Wouldn't the storage vessel be a communicating vessel?-- jmvw, Jul 05 2006 Detail is essential. Possible... well, it sometimes helps. The bladder is here because it's a good word. The turbine is not in the sea because it's on top of the bladder. The storage vessel communicates with the bladder via the turbine. The communicating vessel is moored in the bay and beams telemetry from the turbine via satellite. Got it?
Sorry [methinks] - hijack averted, plane back on course.-- wagster, Jul 05 2006 That is the quickest chown I've seen in a while [wagster].-- methinksnot, Jul 05 2006 What's a chown?-- wagster, Jul 05 2006 "Change ownership" it's a UNIX command.-- methinksnot, Jul 05 2006 Aha, I call it CDLLAP - Copy Delete Logout Login Annotate Paste. Chown is better.-- wagster, Jul 05 2006 Why bury it? Why not just shape the bladder like a beached whale?-- MoreCowbell, Jul 05 2006 Underwater turbines are in current research phases, and do much better than this one by placing it in a high current area.
The challenge is having moving parts in saltwater, where corrosion means lots of service needed (compared to wind turbines), and also the environmental impact of cuisinarting marine life, esp. in rich tidal areas.-- sophocles, Jul 06 2006 Perhaps this could work if the communicating vessel were very large. Such as a bay. And the bladder too, such as an ocean.
I think it might be helpful to reduce speeds or rotating parts: aim for large slow moving components, such as a very large slow turning horizontal turbine, rather then fast moving turbines. This should help save the marine life and it will reduce corrosion problems.-- jmvw, Jul 06 2006 If you have ever lived on or near a beach you will discover that sandy beaches can change greatly over time. I have seen beaches move inward and outward 50 feet over a few years. It would be difficult to place something in the sand and have it stay covered.-- MoreCowbell, Jul 06 2006 Just to make a clarification here. This is a closed loop system. There is no contact with the outside water or with wildlife. There are 2 moving parts the Turbine(which is realtively small) and a check valve. This also eliminates any issues with corrosion as the only parts to contact seawater are rubber or plastic. The entire point here is that this would not be visible and would not harm wildlife etc.-- jhomrighaus, Jul 06 2006 What replaces the water in your storage vessel when the water withdraws? Not vacuum, I'm sure. If air, wouldn't be some part of the system visible?
Perhaps your system should have two bladders, one downwave from the other. And no foam, gravity would take care of refilling the upwave bladder.
I still think it would be more efficient to do without the bladders and just put the turbine in the sea.. Corrosion can't be that big of a problem.. steel ships deal with it it all the time.-- jmvw, Jul 06 2006 This is a fine idea, with many excellent components. Two communicatingbladders with a turbine between. Tide in: bottom bladder compressed, top bladder filled. Tide out, top bladder drains, botoom bladder fills. I like the use of tide for gravitational energy, I like the concealed aspect and I like that the moving parts and widgets are kept safe from the ocean.-- bungston, Jul 06 2006 I too like the 2 bladder approach. i will incorporate that into the idea. This should allow generation in both directions. thanks [jmvw]-- jhomrighaus, Jul 06 2006 Surely a water turbine is a hydrine?-- wagster, Jul 06 2006 OK, so a contained system of 2 bladders with a turbine between.
However, this would rely on a pressure difference between the 2 bladders. Would you get enough pressure difference?
1. You'd have to put one bladder under a wave, and another where no waves go.
2. You'd have to have compressible sand. This is the hard part now. You wouldn't need compressible sand if you put this above the sand, below the waves.....
I still am more enamored with higher energy possibilites such as the concept of turbines under, say, the Golden Gate bridge (a few billion gallons of water move through each day). (No more fishbone here, though)-- sophocles, Jul 06 2006 random, halfbakery