A Submerged River Mill ??

[PepeLapiu]

Hi all, I am thinking about buying an off-grid land and build a house there. It will be on the side of a river so I can install a home mad river water wheel for electricity.

I live in Northern Alberta where there is often 2-3 feet of ice in winter, even on rivers. So I will need to make the turbine part completely submerged. Unlike traditional water wheels, this one will be turning on a vertical axis. So that the whole wheel will be submerged under the ice, thus never freezing in winter. The wheel will rotate around a pole driven into the river bed. The pole will also stick out of the water/ice level and a shaft following the pole will take the wheel rotation to the generator above water.

One of my concerns is the strength of the pole. It will have to be strong enough to resist the ice flows of every Spring as the ice melts and flows down the river. But that is a minor problem. I am mostly concerned with the amount of electricity I can generate with this water mill. How much of water flow will I need to put my mill in and how big should the 8 blades be to make 5 kW/hour?

I wish I could post a sketch of the wheel for clarity but I am able to do this at the present time. Do you know of anyone who has made a submersed water turbine? I know it would not be as efficient as a wheel partly in the water but that would not work for my -35 Celcius Winters up here. But I think I can make some sot of a cover on the upstream side of the wheel so that the flowing water will only act on the downstream side of the wheel.

Any ideas? Suggestions? I hope I would not need too much of a current in the river as I would like to use a boat in front of the house if possible. The house will be a beautiful log home with fireplace and cathedral ceilings and all, completely off grid with possibly no access by car, only with snowmobiles, ATVs and boat access will be possible. The main obstacle t this dream is the ability to generate some electricity. Any feedback will be appreciated.

Thanx,

PepeLapiu  

[PepeLapiu]

I composed a poor man's drawing of what I am talking about. Here it is:

http://www.otherpower.com/images/scimages/9634/b473_1_.png

This is a look at the wheel from above, as if your were looking down from a boat.

The blue arrow denotes the direction of the current. I only drew 4 blades but there will be 8 of them. The wheel will be about 5-6 foot in diameter and the blades will be 4-5 foot tall, water depth allowing. The red half crescent represents the casing which would shield the upstream side of the wheel from getting too slowed down by the current.  

[TomW]

Thought I would save you folks  having to cut n paste the link to the drawing.:

[PepeLapiu]

Thanx Tom.

An electrician told me that if I use only electricity to heat I will require an average 24,000 kWh (84.1 GJ) each year. I wrote above that I need the generator to make 5 kW per hour but I could be wrong, don't know much about electricity.

Mainly I would like to know how much of a water flow i will require in the river to get all that power.

Thanx all,

PepeLapiu  

[wdyasq]

It would be extremely hard fore someone to recommend a size of a device that is only an idea.

I don't know how knowledgeable your electrician is or how honest he is.

You might want to look at the 'Gorlov' turbine. I think there is test data on it. It will take a bit more expertise to build but it is somewhat proven and there have been working models in the water.

Ron

[finnsawyer]

Basically, what he is proposing is a VA(Water Turbine).  Such a thing should operate pretty much like an air version, except the water is denser and heavier.  With the red casing the blades will be carrying water around with the result that that water must rejoin the flow on the left causing water to be deflected beyond the blade tips with a loss of power.  Forget the casing and go to a bucket (egg shell?) design like the air VAWTs.

I don't know whether he could do a horizontal arrangement instead.  There is no reason he couldn't drive a pipe into the bottom.  He would need a 90 degree gearbox.  That could be a problem underwater, or at least expensive.

[jmk]

 They already make them. I just saw a show on the science channel where they put three of them down at the bottom. They are in New York, and are using the tidal currents. The first time they put them down the blades broke on all three. The current was to strong. They are only about eight foot rotors but kick out 25 kw. They modified the blades to make them stronger, and they are doing fine now. They look just like a three bladed wind turbine (hawt) except the blades are wider. They look like a trolling motor but the blades aren't as wide.

[PepeLapiu]

The 24,000 kWh figure was corroborated by a study from 1997. But since that time appliances and electricity usage have changed a great deal. I would be using a gas or propane stove and the home will be extremely efficiently built with me being an insulator by trade. Also I suppose I will be using CFL's instead of incandescent lights and some of the heating could be done with a wood stove to help but I don't want to depend strictly on wood for heating. So the 24,000 kWh per year is a bit high for sure but I would rather aim high and have some power to waste then aiming low and ending up with not enough.

I think the Gorlov turbine would run on an horizontal axis, no? A gear box would add complexity, cost and also some power lost would result from it too. I like the vertical axis better, it's far easier to build and maintain. I could even build 2 or 3 of them if one was not sufficient.  

Thanx for your reply.

Cheers,

PepeLapiu  

[PepeLapiu]

Water is 800 times more dense then air to be precise, this is what makes it interesting. Also, a river always flows while the wind is not as dependable up here.

I am sorry, I don't understand what you mean by a bucket or egg shell design. Can you be more precise please?

I agree that it would be more efficient if the blades were empty upon exiting the red case. But I am hoping the pressure of the flow can be sufficient to generate some torque..... don't you think? A good design would have the upstream side out of the water but that isn't possible with the winters up here.

The horizontal 90 degree gear box would be a great thing, only I am afraid that would be very expensive, no? It would also require some maintenance such at lubricants to be constantly added and inspections. Too bad water itself can't be considered a good lubricant. But just imagine having to cut a hole in 3 feet of ice to go down in freezing and moving water to lubricate a gear!

Thanx for your reply, I will still try to look into the 90 gear box if that can be done reasonably.

Cheers,

PepeLapiu

[PepeLapiu]

Can you be more specific on which TV show and which TV channel you saw this on? I would be very interested in getting more details about that.

Thanx,

PepeLapiu

[PepeLapiu]

I found an article on the subject:

http://www.sciencedaily.com/releases/2006/06/060614120238.htm

They also mention that under water gear boxes are high maintenance and expensive

[electrak]

Hi there, just thinking( no experiance ) Seeing that in a river the water flows in one direction and is 800 times the force as air, Have a propeller in a tube ~4' well casing maybe? with the bearing around the outside of the prop. Place the magnets on the outer edge and the coils inbedded in the bearing. Using plastics as the bearing( teflon, UHMP, ect.) Water will lubracate these to some degree. It will need some sort of protection from sticks and stones.

[kenneth keen]

Nice to see someone starting something I myself started ten years ago. I live in France where I have at least a dozen neighbours who own and operate mills and who I look to for advice. One major point is the "sticks and stones". One operator who is thankfully running an "over the top" wheel said that you should never have an undershoot wheel. He gets his wife to go out there at least twice a day to clear debris that has collected on the surface of the river, since when this gets between the wheel (or turbine) then you can have a major operation getting it dislodged. With a turbine constantly under the water then you will need a filter which is accessable all the time (or very very efficient). Another friend who has a major piece of mechanical equipment automatically raking the four metre (12 feet) wide metal grill or filter, had to turn the whole thing off in the Autumn (November) as the amount of leaves on the surface was too much to deal with.

Since you are an insulation expert that is a major advantage regarding heating your place. Remember that no one (who has limited resources) ever uses electricity to heat a home. If you don't mind keeping a stove running, then with correct insulation, you should be able to keep the whole place warm enough. It is better to spend thousands of dollars in the construction of your house just on insulation than thousands of dollars each year on heavy equipment which must be replaced since you are trying to generate kWs of energy which is then just seeping through the walls and roof.

Regarding the pole which you are worried about in the centre of the turbine: if the river is frozen around the pole it needs to be kept turning so that the pole does not freeze solid. If this ice is three feet thick and is more or less a mini-glacier then the amount of pressure that it will put on the pole will be enough to move it. A photo would help make the situation clear.

I have little ice to deal with but due to all the above and other problems I have not build anything serious yet, not wishing to see equipment washed away or rust solid. I am still researching various methods of gaining HEAT from the water, both mechanical and thermodynamic, but have seen NOTHING which operates without a huge amount of hassle. My own pet idea has been to mount whatever I do build on a raft, that way the flow is constant.

Best of luck with your project and don't rush into something which drains your dollars too quickly....

[wdyasq]

The Gorlov is a vertical axis device.

Using 'Gorlov' alone as a search term in Google, the first 6 hits were on the Gorlov turbine.

If you care to build an unknown device, it is your choice.

Ron

[finnsawyer]

I'm sure you have seen pictures of commercial anemometers.  Those cups are like half an egg shell.  That's what I'm talking about.  People build V(ertical) A(xis) W(ind) T(urbines) out of half steel drums.  That's the bucket form.  The basic processes of the VAWT should also work for water flow.  I'm not going to explain it.  It's been covered extensively on this site.  Do a search.  

[ebby1234]

Have a look at this site that is if I have managed to copy it correctly(www.bluenergy.com/davishydroturbine.html)

[PepeLapiu]

OK, buy bucket  or egg shell, I thought you meant the case of the turbine but I can see now that you are talking about the blades themselves. Sorry for the confusion.

[PepeLapiu]

OK, I found it, looks very interesting. However I contacted them to find out if they would sell me a turbine or the blueprints and they haven't replied

[PepeLapiu]

>> I live in France

Je viens de Quebec alors je parle Francais aussi.

>> One major point is the "sticks and stones".

I plan on getting the hole thing under water so the floating debris won's be to much of a problem for me.

>> One operator who is thankfully running an "over the top"

>> wheel said that you should never have an undershoot wheel.

I am sorry but I don't know what you mean by "over the top" and "undershoot"??

>> Remember that no one (who has limited resources) ever

>> uses electricity to heat a home.

Not true, in Quebec most people heat their home with electricity since it is so cheap there. In fact if I can generate enough from my turbine, it will be free so I might as well use free electricity rather then anything else, no?

>> Regarding the pole which you are worried about in the

>> centre of the turbine: if the river is frozen around

>> the pole it needs to be kept turning so that the pole

>> does not freeze solid.

I already have a solution for this. A tube will surround the shaft (or pole) and between that case and the pole an anti-freeze will be poured in. The anti freeze will have to be biodegradable should it leak out and it will be lighter then water so that it should float in the case. I don't know what i will use yet, vegetable oil maybe? But the ice can freeze around the tube or case but inside the case the shaft remains  in anti-freeze and free of ice.

>> If this ice is three feet thick and is more or less a

>> mini-glacier then the amount of pressure that it will

>> put on the pole will be enough to move it.

The more I think the more I realize that planting a pole in 3 foot of ice and expect it not to move is too much of a challenge. I think it would be safer to make it that I can remove the top portion of the pole ans shaft along with the motor on top during the ice flow season. So for a few weeks I would have to live off of a gas or diesel generator.

>> Best of luck with your project and don't rush into

>> something which drains your dollars too quickly....

Thanx for the kind wishes. I have to figure out a way to make some electricity or this remote log home dream of mine can not be sustained.

I think I should first make a scale version of my mill and try that out. If it works I shall build a full size one with either aluminum or titanium for corrosion protection.

I like your raft idea, it might save me the trouble of having to drive a pole into a muddy river bottom and see the ice sweep it away every Spring. But with a raft I would have to sacrifice the raft every Fall and watch it get frozen stiff or live an other few weeks without power until I can walk on ice and install the turbine on ice again.

Cheers,

PepeLapiu

[PepeLapiu]

Found this:

http://www.optimset.com/index.html

Might be promising.

[jmk]

   The name of the series is Building The Future, and the show is The Search For The Ultimate Energy. The turbine is bigger than I thought. I'm not sure on the specs, they never said anything about the size. I was guessing from what I could remember from seeing it previously. I saw it again tonight and it looks to be around 18' or so. Some pictures it looks bigger and others make it look smaller? Sorry I couldn't get back sooner. I watch a lot of science shows and couldn't figure out which show it was until I saw it again. I get the program from Direct tv channel 284. I actually looked this show up on the discovery site. I couldn't find the exact show, and it made me feel as if it was done airing but they showed it again tonight. Wed 7:00 Jan 30th science channel 284. I thought that they had made three of these but when they said all three broke because the current was to strong they were talking about the three blades on the one turbine.

[TimV]

First ask yourself why dams on small streams that have been there for years and years are made out concrete mesured in feet of thickness and not inches. This should give you an idea of how thick your "pole" would need to be to withstand the fury of a raging iceflow. I read once water was one of the most powerful forces on earth. I still believe that.  Add ice and you have water power on steroids...(And I only thought baseball players used steroids.)

 I must admit I saved the links to the submersible generator you posted.

See if you can find any info on the old Chase Machinery Building generator in Orange, Mass. It had an operating year round turbine generator with some similarites as to what you describe. I think mother nature will be your biggest obstacle to surmount . It supplied power to several city blocks as I remember.

I think if you google "Chase turbine" or Chase machinery" add Orange Mass if nothing comes up.

[kenneth keen]

Sorry I was out of touch for a while. To your own comments:

>I plan on getting the hole thing under water so the floating debris won's be to much >of a problem for me.

That is a good, but also remember that a lot of debris and stones just get swept along the river bed and will end up stuck somewhere in your mechanics. A very heavy metal grill is what is used in France - costs lots of money of course.

>> One operator who is thankfully running an "over the top"

>> wheel said that you should never have an undershoot wheel.

>I am sorry but I don't know what you mean by "over the top" and "undershoot"??

Over the top means that the water flows over the top of the wheel and undershoot means it flows under the wheel.

>> Remember that no one (who has limited resources) ever

>> uses electricity to heat a home.

>Not true, in Quebec most people heat their home with electricity since it is so >cheap there. In fact if I can generate enough from my turbine, it will be free so I >might as well use free electricity rather then anything else, no?

It is just that most people cannot easily produce large amounts of electricity. If you can only produce (after a lot of effort) 1kWatt then it would be silly to use this just for heating as it would not be too effective in making a house warm but it would be very effective in giving you lights all over the house, music all around and computers and small motors and machines etc.

>> Regarding the pole which you are worried about in the

>> centre of the turbine: if the river is frozen around

>> the pole it needs to be kept turning so that the pole

>> does not freeze solid.

>I already have a solution for this. A tube will surround the shaft (or pole) and >between that case and the pole an anti-freeze will be poured in. The anti freeze >will have to be biodegradable should it leak out and it will be lighter then water >so that it should float in the case. I don't know what i will use yet, vegetable oil >maybe? But the ice can freeze around the tube or case but inside the case the shaft >remains  in anti-freeze and free of ice.

Sounds ok in theory, I imagine that a lot can go wrong in a real situation ie the leak will happen and it is a messy result that you get which is not very nice to have to look at. Nor will the wildlife be grateful for this.

> So for a few >weeks I would have to live off of a gas or diesel generator.

Good that you are flexible in your thinking.

From what I can remember it is the HEATING that is your main requirement. As I said at the start then check that you INSULATE correctly and (like the eskimos) you will be amazed at how little energy you will need. It is great to have your own little machine running away shifting power from the river to where you need it but I have never in my life seen an independent system which is sturdy enough to be able to withstand nature's forces and yet still be affordable or practicle.

>I think I should first make a scale version of my mill and try that out. If it works >I shall build a full size one with either aluminum or titanium for corrosion >protection.

That is a very good idea, small first, just to see how it works and then full scale once you get the thing balanced.

>I like your raft idea, it might save me the trouble of having to drive a pole into a >muddy river bottom and see the ice sweep it away every Spring. But with a raft I >would have to sacrifice the raft every Fall and watch it get frozen stiff or live an >other few weeks without power until I can walk on ice and install the turbine on ice >again.

A raft can be made of treestems bound together and then your machine set on top. Dismantled and then set somewhere safe each winter is one solution...not so sure that this would satisfy you;-)

You haven't given up have you?

Kenneth Keen

[kenneth keen]

Well I am still alive but I don't know about our friend on the ice! I ended up buying a 140kg steel stove to heat my place not willing to experiment with things twisting in the water and maybe getting destroyed and then destroying all in their path as they move downstream. Needless to say that a stove burning 35kg of wood a day was also not a solution which satisfies. Cutting wood, storing for two years, moving from one place to the other and then constantly watching that the fire does not go out is not my idea of a smart solution to keep warm.

Smart is moving 3000kms south if necessary. Then leaving the door open since it is not necessary to heat when the mean temperature is already 15˚without burning a think. Then moving back north when the sunshine returns. 

Good to see the site alive still. Haven't stopped all my experiments but just need a pair of spare hands to be able to turn my system on. Even then if it works I will just have a 16mm steel cable of 35m which turns once a second, but with a lot of torque. What I connect it up to still remains open. First have to get it to be switchable. Set it in motion, turn it off. Not easy when you are dealing with 3 tons of water gushing past every second.

[Mary B]

Winter use brings up the problem of water flow also. Many streams the flow goes to a trickle in winter.

[kenneth keen]

"Many streams the flow goes to a trickle in winter"

Well that was a useful comment. I will take a note of that in my book and tell my friends too

[XeonPony]

Winter use brings up the problem of water flow also. Many streams the flow goes to a trickle in winter.

I'll let the pile of  machinery at the bottom of the raging river know that once summer hits and I can get near it!