Hydrokinetic clean energy systems

[Freegrass]

Moved this over from the freeform season chatter thread. I started this discussion over there while drunk, but I would love to debate this a little further while sober.

Is my device even possible? I've been thinking about this for more than 20 years now after I became a diver and was confronted with these oceanic forces. But the lessons I had on mechanics in high school aren't sufficient to make all the calculations. I don't know how to convert force into energy. I just know there's a lot of potential energy in the ocean, and I keep wondering why these ocean pressures and currents still aren't being used on a large scale to create energy. (we can discuss the Pelamis and other devices in this thread also)

1 bar is 10 metric tons of force per m²
At 10m depth, you already double the pressure to 2 bar.
At 50m you have 6 bar, or 50 ton of force/m², or 5kg/cm²

So there's a lot of force in the ocean that you could utilize to generate energy. The problem is getting that device back up. I presume that conservation of energy dictates that you would need the same amount of energy to bring that device back to the surface than what you were able to generate at the bottom. So it's basically impossible to use that force to generate energy.

BUT! And this was the big insight I had - what if you could use ocean currents to bring that device back to the surface? Then the amount of energy you would be able to generate would depend on the strength of the ocean currents. And I know how powerful ocean currents can be from when I went fishing with my dad in the north sea as a kid. The first time we threw anker I was so surprised how fast our zodiac went over the current. It was as if we were still having the engine on. Filling a bucket with water had to be done carefully, or I could have been pulled out of the boat.

So after a lot of head breaking over many different ways to use marine power, I eventually came up with some kind of underwater kite. This kite would be connected to the ocean floor, and "fly" up and down through the water column in an 8 shaped pattern. Computers would control the kite, and those kites would be slightly positively buoyant, floating 10m beneath the surface of the ocean at slack tide - as to not interfere with traffic on the surface.

The kite would thus be able to start at 10m depth when the current picks up, to maybe 50m or deeper at full current strength, constantly moving up and down to generate energy with the water pressure. Would such a device be easier to maintain than underwater turbines? The principle is much easier, with very few moving parts. So would a device like this work?

I just find it so frustrating that we still don't have a device that can generate energy from ocean currents, and this idea has been in my head for more than 20 years now. So please help me out of my misery!

Unlike last year at this time, this year there is not a pile of thick ice near the Fram Strait vulnerable to export.

And Cryosat still insists there is

It is confusing to have such inconsistency between HYCOMM, PIOMAS and CS2SMOS. I'm leaving out Mercator because my brain can only handle three things at a time. Cryosat is the source data for CS2SMOS so they should be the same. My guess is that CS2SMOS is just a more smoothed version of Cryosat. I hope the differences can be resolved and a winner chosen by the end of the 2021 melt season. Perhaps comparing what the different models say now vs. the end-of-season condition will allow judging which of the current estimates was most realistic. The presence or absence of thick ice along the shore of ESS east of the New Siberian Islands (prominent band of 4M in PIOMAS, thin sliver of 3M in HYCOM, nothing more than 2M in CS2SMOS) could be a good test case. Or it may not reveal much because if it disappears by Sept. the CS2SMOS fans would say "See, PIOMAS was wrong", and the PIOMAS folks would say "There was a lot of melt along the shore of the ESS this year." Perhaps the analysis of thickness data from MOSAIC will bring improvement and better harmonization of thickness models. To the degree feasible, it would be great to get model validation data by measuring the actual thickness at sites where the models disagree. Maybe the U.S. and Soviet (and who else?) submarines playing cat and mouse in the Arctic Ocean could take Sundays off to resurface, take some ice cores, then go back at it on Mondays. A profile of the late great Wally Broecker said he used discrepancies as his best learning opportunities. I hope somebody is doing a PhD on the great ASI thickness model debate. Carl Sagan said "Extraordinary claims require extraordinary evidence". A corollary is "Different claims require that not everybody is correct," (not necessarily that somebody is right and somebody is wrong because they might ALL be wrong). John Lennon said "Just Gimme some Truth!"

If you had a torpedo shaped underwater device with a propeller and wings to make it go up and down in the water column, would you be able to power it with a piezoelectric generator and measure ice thickness uninterrupted the whole year round?Does such a device exist? From the surface to 10m depth, you double the pressure, and every 10 meters you get another 1 bar of pressure. So 6 bar at 50m depth. And the same energy again when you go back up and reverse the process...How much energy would you be able to generate with a piezoelectric generator, and could that energy power a measuring torpedo under the ice?I've been thinking about this for so long... Can anyone help me with the calculations? I have no idea if a device like this could ever work...I also have a design in my head to generate power with a piezoelectric generator in the ocean, but I lack all the education to do the calculations...Can anyone help me out of my misery?(it's alcohol day. I hope I'm still making sense...)There's a little problem of buoyancy... The propeller and the wings would have to be able to overcome positive and negative buoyancy of the piezoelectric generator...You could use current for that in an oceanic piezoelectric generator, but now I just gave away my brilliant idea that was gonna make me rich... PLEASE HELP!If we could figure this out, we wouldn't have to worry about energy ever again... Because it's so simple... I can imagine underwater kites going up and down in the water column to generate infinite clean power...I just need to figure out how efficient that would be... And I don't know how...

A torpedo shaped device that creates it own piezoelectric energy by propelling itself forward so it can go up and down in the ocean column with its own wings and engine to create more energy to move forward and up and down is basically a perpetual motion device, isn't?Is it possible? Or did I smoke too much shit?

All you really need is to sheath your glider in a wax that melts at about -1C and coat it with rubber. The expansion will give you positive buoyancy to glide upwards, near surface it freezes, contracts and you glide down. Trivial battery capacity would be required for it to autonomously rescue itself from situations where the temperature differential stops this working. A propellor/turbine for charging during gliding, or powered flight is trivial. You could also pressurise an emergency compressed air blowtank by capturing a bubble at the surface, everytime you come up in a lead to transmit, and using depth to pressurise it into your storage tank.Wax piston actuators have been used in engineering for a very long time.Such a vessel equipped with all the necessary sensors nav and com systems could be built for under 500€ these days. A midrange cellphone reprogrammed could handle most of it. You can find plenty of kids with the necessary skills and experience on YouTube.For those interested in the electronic design constraints of the satellites we rely on for viewing and data of the polar regions, and Apollo, it's a far more difficult business than for submersibles. I attach a PDF from MIT satellite and probe design school for your reading pleasure.

A torpedo shaped device that creates it own piezoelectric energy by propelling itself forward so it can go up and down in the ocean column with its own wings and engine to create more energy to move forward and up and down is basically a perpetual motion device, isn't?Is it possible? Or did I smoke too much shit?

Perpetual motion devices are certainly considered outside the realms of the possible. And the device you describe would not function - I think a small nuclear battery like they use in satellites would be the best bet.Anyone for crowdfunding our very own nuclear sub in the Arctic?

[kassy]

There are many projects looking into wave harvesting and being close to the coast is possibly a pre.

Just checking out an idea is not policy and solutions.

[etienne]

I think the idea could be used to store energy. I see 2 possibilities.

1 - A pulley could be placed at the bottom of the ocean, and a cable would pull the element down when energy is available, and the element could go up when there is a need for energy.

2 -  you could put a balloon at the bottom of the ocean, and blow it up when there is enough energy, and use the pressure for example to generate electricity when needed. It should be possible to store a lot of energy in the balloon because of the pressure. And the pressure would be constant from the beginning to the end.

In a current, I heard of turbines, and of a project with elements connected with an electricity generating device that would produce electricity when everything moves. I don't think that the project ended with something financially interesting.

Just checking ideas could be walking the walk, in the past, topics have been moved when not in the right category.

[Freegrass]

That's actually a good idea Etienne. Instead of pumping water uphill into a reservoir, you pump air down into the ocean in some kind of bladder.

Shall we start a company? 

The problem with compressed air batteries is efficiency because of temperature. But those are being worked out.

[etienne]

The temperature issue might not be so complicated, at the bottom of the sea, overheating must be almost impossible, and on the other side the cold could be recycled to keep the fish at a low temperature. You just need a turbine that works at low temperature, which should be possible do create. The only issue is to have air that is dry enough so that you don't have condensation in the turbine.

Add a windmill to pump the air, and we created a refrigerator that that works with wind power and has electricity as byproduct.  A cool project that could probably be financed by some foundation or government and could solve so many problems in remote locations.

Added : I just don't know how long a bladder can survive in salted water.

[Freegrass]

Belgium again leads the way in small hydrokinetic clean energy systems.

Could the future of energy be found in rivers? At Turbulent, have no doubts about it! Our micro-hydropower technology opens possibilities to generate clean, renewable and reliable energy in places that were never viable before. In this video, you will find a complete explanation on how we can help you generate green energy for the local people, to help the planet while making a sustainable profit. Start your project now on www.turbulent.be

[Freegrass]

Oops... It looks like someone else already came up with my idea of an underwater kite... 
This system though uses the kite to speed up a turbine instead of my idea to use the ocean pressure at different depths.

Maybe I should contact them so they can add my system to the kite? 

[NeilT]

If you really want to bend your mind on what is, essentially, a gravity engine, think on this.

What holds a ship up in the sea is the same force that tries to sink it.  Because the "weight" of the mass of water you displace, to create the buoyancy, is created by the gravity pushing down on the mass of water you are displacing.

Of course once you get into the water, things change.  Creating buoyancy at 2 bar takes energy, which can be harnessed to give back energy when the buoyant vessel rises to the surface of the water.

The difference between an attempt to reset an above air gravity engine (lifting the weight back up again) and a below water gravity engine, is that things weigh less in water than they do in the air. 

Flooding and returning to the start point is free, donated by gravity.

Creating the buoyancy is an interesting one, because there is the possibility to have reservoirs of force both outside the water (weights above) and in the water (chambers of buoyancy).

The question is whether the same rules of conservation of energy apply in a water borne environment where the very pressure which creates the forces you are using, donated by gravity, also affects the weight of the vessels you are using.  The mass is the same, but the weight, mass being affected by gravity, is different.

Personally I think that smart engineering, materials and a whole load of effort could produce something which would deliver energy by utilising the multiple gravity fields of above water, in water and on water.

Now here's the kicker.  It would deliver such a small amount of energy for such a massive infrastructure that you would be far better off dropping turbines in the ocean flow, with or without  large anchored funnels and take the power out direct.

These ocean flows are not stopping any time soon and will deliver power for up to 20 years without replacement.   The method has already been tested in the Scottish isles and is currently deploying in Wales and Canada.

These are mainly tidal devices, open ocean flow has the potential to deliver far more power, just as wind turbines have improved in performance for massive offshore as opposed to onshore.

Some links.

http://www.emec.org.uk/marine-energy/tidal-devices/
http://www.emec.org.uk/marine-energy/wave-and-tidal-projects/
https://www.novainnovation.co.uk/bluemull-sound