Capillary action Hydro-station

[Double K]

This is something I dreamed up and was wondering about the feasability of it, so assuming no one steals the idea (if it is even possible) then it could mean cheap & clean energy.

 

I'm no chemist/bioligist/mathematical genious, however I think this could work although from research I have done into this system there are some problems to overcome.

 

The premise is this:

 

Trees can use capillary action to transport water (in the case of old red-woods they are known to transport up to 4 tonnes or 8,000 lbs from ground level PER DAY! sometimes hundreds of feet up.)

(source) http://www.davidlnelson.md/Cazadero/Trees&CapillaryAction.htm

 

So with this in mind, I discovered they were able to replicate this in a lab but were only able to get water to a height of 28 feet (sadly I found this link a few weeks ago and can't find it again but it's out there in the ether somewhere) 28 feet is still considerable, and also if you could stack towers each 28 feet high, you could possibly achieve a higher total effect.

 

The "Hydro-station" would be a system using capillary action to transport the water to a high point and then capture the energy thru standard turbines as it falls back down - this could be a closed loop, essentially providing perpetual energy from a small water source (of course there would be losses due to evaporation, however these would be minimal.)

 

The main problem with capillary action is extracting the water at the top of the system. Trees of course have the sun to do it for them, which then vaporises slowly through the leaves, a power generating system would need to extract the water much faster than this, but the water is there, there must be a way to leech it out at the top! What would best do this!?

 

Also I see a small laser etched silicon cell that causes capillary action, so perhaps this technology could be used to create the system, in which case I imagine extracting the water at the top of the system would be easier...

http://pesn.com/2010/03/18/9501628_Laser-etched_silicon_draws_fluid_upward/

 

How do you solve the problem of extracting the water at the top of the system. How high can the system go, what would limit it? Gravity - pressure - etc.

 

Low pressure head turbines could also be utilised in the 'dams' at the top and bottom of the system also.

[Mr Skeptic]

First of all, you won't ever make a perpetual motion machine.

 

Second of all, capillary action is only one component of the tree's water transport system. Equally important is that water evaporates at the top. Think of it this way: you put a straw in a glass of water, nothing much happens. You suck on the straw, water goes up.

[Double K]

A straw isn't a great depiction of capillary action really, and to some degree you are right, in that the tree doesn't just use straw like structures to transport the water.

 

Capillary action, or capillarity, refers to certain phenomena associated with the behavior of liquids in thin tubes or in porous materials. Liquids, such as water, will tend to move "up-hill" (against the force of gravity) which does not normally occur in large containers. The interface between liquids, or a liquid and a gas, can form a meniscus or crescent shape.

http://en.wikipedia.org/wiki/Capillary_action

 

Capillary action does not require suction, and has been achieved in labs with no source at the top "drawing the water" but through molecular bonds that occur (basically the water climbs up itself) The problem has been extracting the water at the top of this system.

 

No system is really available for power that provides zero losses and so "perpetual motion" is likely not to be an outcome, but in a closed system where none or little of this water or fluid could escape then losses could be significantly reduced...

 

http://www.timedomaincvd.com/CVD_Fundamentals/xprt/Plug_n_Pois.html

 

Finite Viscosity: Poiseuille (fully developed) Flow

 

If we consider the case of flow in a pipe or channel when Re is low BUT after the flow has been in the pipe for a distance much longer than the entry length, the fluid velocity will vary with radial position. The velocity must be zero exactly at the walls, and viscosity causes the velocity to be small in the vicinity of the walls. Therefore the flow in the center is actually faster for the same volumetric flow.

 

 

In the case of a cylindrical pipe with flow along the axis the velocity distribution is a simple quadratic, known as Hagen-Poiseuille or simply Poiseuille flow. A residence time and volumetric flow can again be defined in terms of the average velocity, but in this case the residence time is an average: streamlines near the center spend less time in the channel, and streamlines near the walls have very long actual residence times.

 

 

When large pressure differences exist across a long pipe (so that Re stays fairly small) one can integrate the Poiseuille formula to find the molar flow through the pipe (which of course is the same at all locations along the pipe in steady state)

[insane_alien]

his point was that trees don't depend purely on capillary action. if they did then there would be no tree taller than 10meters.

 

you couldn't stack towers either. not how it works.

 

if this was in any way viable then it would already be used.

 

going back to the tree part, trees actually have to expend energy to get 4 tonnes of water per day. that doesn't come for free. in fact, aside from growth an maintenance i'd suspect thats actually the trees biggest energy usage. it eneeds to set up chemical potential gradients in order to pump the water up and this takes energy. if these didn't exist then trees would not get to the size they are.

[PaulS1950]

Whether the process is actually feasible or not you can "stack" the towers as long as each tower begins with a resivoir. Use the capilary action to get water to the first rservoir and then use another to lift it to another, and another - each time the reservoir would be open to atmospheric pressure and the next stage could lift from there.

I do think it would be difficult, if not impossible to get enough volume in this way to be a usable power source - even for a single unit dwelling but I like the creative effort.

[Sisyphus]

It won't work like a neverending pump, because capillary action is not an input of energy. It's passive. If the capillary action gets a certain quantity of water up a certain height (giving it potential energy), then it will take more than that amount of energy to get it out of those tubes.

 

Think of it like a magnet - you can extract energy from the force pulling two magnets together, but then you have to use more than you extracted to pull them apart again. Capillary action is the same thing, just with the adhesive forces between solids and liquids. Water up in the tree is actually the lowest energy state, despite the additional gravitational potential energy, because you've used up the potential energy of the intermolecular attractive forces. A tree can keep sucking up more and more water only because there is an energy input - the sun - evaporating water at the top, making room for more water, etc. Like if you had a chain being pulled towards a magnet, and every time a new link touched the magnet, you pried it off. It would keep pulling the chain, but you'd have to keep using energy to pull new links away.

 

In short, you can't ever get more energy out of a machine than you put in.

Edited May 6, 2010 by Sisyphus

[Double K]

the adhesive forces between solids and liquids. Water up in the tree is actually the lowest energy state, despite the additional gravitational potential energy, because you've used up the potential energy of the intermolecular attractive forces. A tree can keep sucking up more and more water only because there is an energy input - the sun - evaporating water at the top, making room for more water, etc.

In short, you can't ever get more energy out of a machine than you put in.

 

Ok yes, I realise there is always losses in ANY system.

 

However, if a chemical was added to break these bonds at the top, then that would solve the problem no?

Or if a vacuum existed at the top (which goes back to the straw analogy I suppose)

Just how much pressure would be needed to extract the water at the top? Because that's really the key, and could the system provide enough energy to power something simple enough (and with left-over power for elsewhere)?

 

Initially it's true that alot of energy would need to be expended to kickstart the system. Lets imagine this for example a standard - modern - hydro electric dam the water is already stored at a high point and no energy is needed as it already exists (potentially) with the water at a high point. the system is built on the side of the dam and initially the power to create the suction at the top would have to be supplied but once vacuum was achieved the system should theoretically act much like a siphon hose (although generally those are gravity driven ie the water flows to a low point, however if the suction continued theres no reason that I could not link two basins full of water and siphon continually between the two assuming the vacuum was never broken.

[Sisyphus]

I'm not talking about losses. I'm talking about getting more energy out of a system than you're putting in, which is always impossible.

 

With the chemical idea, you're essentially just using that chemical as fuel. With a vacuum, that's going to take more energy to produce than you can generate using it.

[Skye]

To maintain the vacuum you need a pump that will be supplied with energy. You're not going to get more energy from the turbine of a hydroelectric plant than the pump uses pumping water from the capillaries.

[Double K]

Capillary action is itself a "pump" mechanism, the vacuum pump is merely assisting this much like the siphon hose analogy not alot of energy is required to transform the potential energy of the system into kinetic.

 

Now here's the kicker I guess, is that the energy is already there as potential (and gravity) Hey I'm not saying it's not a flawed system by the way...merely trying to nut out the details...

[Sisyphus]

That's exactly the point - it isn't a pump mechanism. And the system has less potential energy in it when the wick is filled with water. There is no way around it.

[Mr Skeptic]

Yes, there is potential energy in capillary action. It is the surface tension of the water. However, once the capillary is filled with water, there is no more potential energy. Now it will take energy to empty it.

[Double K]

Yes, there is potential energy in capillary action. It is the surface tension of the water. However, once the capillary is filled with water, there is no more potential energy. Now it will take energy to empty it.

 

Actually you just need to break the molecular bonds at the top of the system (this is done in trees by gasifying to vapor thus seperating the component molecules)

Adding a chemical to decrease the viscosity could possibly achieve it?

(although destroys the idea of a "clean" technology as you're then polluting the water source)

 

"A single molecule of water looks like a letter V, with one oxygen atom at the bottom point and two hydrogen atoms at the top. These atoms share some of their negatively charged electrons, forming a strong connection called a covalent bond.

 

The oxygen atom grabs more of the shared electrons, which makes it slightly negative, leaving the hydrogen ends slightly positive. This small shift in charge is what attracts water molecules to each other......

.....The difference in the liquid form is that, at a given time, approximately 10 percent of the hydrogen bonds are broken.

 

Nilsson's group, in contrast, claims that water takes on a new structure, in which a molecule essentially grabs on to only two of its neighbors - with just one hand and one foot. At room temperature, 80 percent of water molecules are in this state, while the rest have the traditional four hydrogen bonds.

 

The implication of this new two-bond model is that liquid water would be made up mostly of chains and perhaps closed rings, as opposed to the tighter network of tetrahedrons."

http://www.livescience.com/environment/041201_water_bonds.html

 

Interesting article actually!

[Mr Skeptic]

Vaporizing water is going to cost a lot of energy any way you do it. Sucking water upwards is still going to take all that gravitational potential energy to do.

 

Look, you have potential energy right now. If you fall down to the floor, you release that potential energy. So here's my idea: fall onto an electric generator. Then get up. Than fall again. Yay, a perpetual motion machine!

[Simpleton]

If I take an extra thin tube and bent the top one inch over the edge of a six inch glass , then that tube is gone drip at a highth of 5 inches even if the 6" glass ihas only 3" of water.

Edited May 7, 2010 by Simpleton
spelling

[insane_alien]

no its not, due to capillary action.#

 

trust us when we say its not going to work. you said it yourself that your no chemist or that. well, we are(and i'm assuming thats why you asked us). and we are telling you that it won't work

[Simpleton]

I can not argue. I am really nobody. I am just slowly learning to express my self and most of what I learned in the last few years comes from her. I did work with aquariums a lot and I seam to remember some instances where a rag or a peace of thin tubing hanging out of somewhat low water tank ended up in the morning with most of the remaining water on the floor on the floor. It certainly gave me the impression that water was released from hire up then the inside level of the tank.

I do appreciate to be corrected

[Mr Skeptic]

A siphon is different. Water goes up, yes, but it also goes down farther than it goes up. You can't siphon water upwards, only downwards. Think of it this way: it is the water flowing downwards that sucks the water upwards. It has to go down further than it goes up, otherwise it can't suck hard enough.

[Double K]

With a siphon the initial force to get the water moving is produced with suction, once the water is thru the hose it can easily continue to flow, however this is gravity fed, so the rest of the draining isnt really capillary, its just gravity...and in this case the bottom of the hose (the free end) must be lower than the top of the hose (the submerged end)

[Mr Skeptic]

You can use a piece of cloth or paper as a siphon as well.

[mortonman1]

i like the idea. but plants use bulk flow as their main way of making the water move up the stem. so when you think of it going up and falling down, i doubt itll work unless you have a root system capable of creating bulk flow for the water to go up the stem. the main source of water going up a stem is sunlight, and/or transpiration. the leaves lose water through its stomata and creates a vaccum so that water goes to replace the area where water just was--- if that makes sense. so for your mackine to work, you need; one, a tree. the tree would use transpiration and bulk flow to get water, but then you would thus extract that water to get it to go down your generators. when you extract the water, that means the leaves DONT get water, and thus the tree dies. so unless you can manually feed the chloroplasts water, it wont perform photosynthesis, and will die. its a good idea though. if you figure out an idea as a counter to this, PM me or reply

[CaptainPanic]

Extracting the water at the top will use more energy than you can get from the turbines...

 

It has to use more energy, because if it didn't you would have invented the perpetual motion machine - which is impossible.

 

If your next thought now is: come on, how hard can it be to squeeze some water out of a tree? Remember that you also don't get a lot of energy from a few m3 of water at just 10 meters high. It doesn't take much to waste all that energy.

[Diddi]

This is something I dreamed up and was wondering about the feasability of it, so assuming no one steals the idea (if it is even possible) then it could mean cheap & clean energy.

 

I'm no chemist/bioligist/mathematical genious, however I think this could work although from research I have done into this system there are some problems to overcome.

 

The premise is this:

 

Trees can use capillary action to transport water (in the case of old red-woods they are known to transport up to 4 tonnes or 8,000 lbs from ground level PER DAY! sometimes hundreds of feet up.)

(source) http://www.davidlnelson.md/Cazadero/Trees&CapillaryAction.htm

 

So with this in mind, I discovered they were able to replicate this in a lab but were only able to get water to a height of 28 feet (sadly I found this link a few weeks ago and can't find it again but it's out there in the ether somewhere) 28 feet is still considerable, and also if you could stack towers each 28 feet high, you could possibly achieve a higher total effect.

 

The "Hydro-station" would be a system using capillary action to transport the water to a high point and then capture the energy thru standard turbines as it falls back down - this could be a closed loop, essentially providing perpetual energy from a small water source (of course there would be losses due to evaporation, however these would be minimal.)

 

The main problem with capillary action is extracting the water at the top of the system. Trees of course have the sun to do it for them, which then vaporises slowly through the leaves, a power generating system would need to extract the water much faster than this, but the water is there, there must be a way to leech it out at the top! What would best do this!?

 

Also I see a small laser etched silicon cell that causes capillary action, so perhaps this technology could be used to create the system, in which case I imagine extracting the water at the top of the system would be easier...

http://pesn.com/2010/03/18/9501628_Laser-etched_silicon_draws_fluid_upward/

 

How do you solve the problem of extracting the water at the top of the system. How high can the system go, what would limit it? Gravity - pressure - etc.

 

Low pressure head turbines could also be utilised in the 'dams' at the top and bottom of the system also.

 

There is another method for transporting the water vertically in a passive manner; evaporation and condensation!

Evaporation due to sunrays coupled with capillary action, even with another very beneficial addition; a fully producing greenhouse incorporated into the design, with last but not least water turbines for water heading back down the irrigation tubes from the highermost point.

 

The implications?

a greenhouse that can evaporate seawater and contaminated water (sun evaporates water from a seperate "dirty" pool), while also using the evaporative action of plants to humidify air. The warm humid air from both/all sources seeks the uppermost point in the closed climate greenhouse, where it can be condensed in a condensation tower, which uses a heat conducting fluid/air/material to capture the heat released as the humid air condenses, transporting it to a thermal mass... which is then used to level out heat spikes for the greenhouse climate.

The plants would furthermore be able to clean sewage water and other organically polluted water without prior, seperate evaporation by sun, instead allowing microbiology and plant biology to break down and incorporate the organic materials back into the carbon cycle of plants and soil.

 

...I'm all for passive, organic or biological "tech"!

That's why I want to marry the fields of computer-/information technology, passive/appropriate technology and biological/organic resources, living and nonliving (byproducts). Information technology is the most capital intensive and frail of the three, but with such incredible potential and versatility... an unmissable tool! I want a collection of DIY communities to spring up around the world and a general trend towards information sharing and massive, cloud or hive-like collaboration between people and workstations: efficient and sustainable utilization of technical resources, basically!

Edited April 27, 2013 by Diddi