Floating water wheel

[MAL]

I have a concept for a floating water wheel that I could use some input on.  I am located on the Mississippi River so I have plenty of water, but not much head.  The water wheel must be light weight so it can be removed when the river freezes over.  My idea is to use whole barrels, attach paddles arround each barrel and an axle through the center.  The barrels would provide flotation and you could use more barrels as necessary to provide as much power as needed.  The paddles debth and size is also adjustable to provide needed power.  My hope is that 2 barrels will be enough to turn a generator or an alternator, but I can add more if necessary.  If you are having trouble visualizing this concept it will look like a rolling pin with paddles. 

Any input will be greatly appreciated,

MAL   

[electrondady1]

fill the barrels with expanding foam

[Frank S]

in open water the Mississippi flows at about 5  MPH  or 440 FPM however near the shore at a distance of 30 ft this could be as low as 50 FPM and right next to the shore say 5 or 6 ft this could be azs low as 20 FPM or less depending on depth I know several places where it hardly moves at all .
 so the first thing is to determine the ft per minute rate near where you plane to install this device
 Remember a barrel has an approximation of 6 ft in circumference. your  floating circumference distance will be 2 times the radius from the center of the shaft to the surface of the water inn  inches  times 3.1416  divided by 12 to get feet divide this into the FPM flow rate to get free RPMs
to figure what size or how many paddles or how many barrels first you need to know what your gear ratio is going to be to spin your generator at the desired RPMs

[kenneth keen]

Whatever you do don't fill the barrels with foam! Besides costing you a lot of money that is an environmental polluting disaster, simply releasing deadly chemicals into the air to propel this gunge into your natural wooden floats. Instead of that collect empty plastic bottles and screw their lids on. Put them in the barrels if you feel that the barrels would after some time begin to take in water. Those plastic bottles can be removed after five or six years should the barrels fall apart or you can use better polypropaline (industrial) plastic barrels which will last sixty years. They have sealable tops and when filled with plastic bottles will take the strain of even ice. You can drive a car over disposable bottles and they will not burst. If you buy new empty bottles they will split - all our industries like to produce crap for consumers but their nasty drinks full of chemicals to make kids' teeth fall out, are put in "disposable containers" which are made to withstand temperature differences of over 60˚and will withstand almost ANY force humans can create.
Your main challenge will be to get some sort of gearing which will turn your very very slow revs per minute, into hundreds of revs to get your generator going. Using long stretches of electrical cord may help if your revolving parts are big enough and the cord does not slip when the load is placed. You don't say how you fix your axis, if it is held top and bottom by ropes from another fixed point upstream or somehow fixed to the river bed.
Go for it! The great thing about making something movable like that is that when the cops or sherifs or whatever those unimaginative office workers are called in your precinct, arrive to complain that you are getting something for free (which is probably just not on, in the land which they used to call free), you can take it out and say "sorry boss, didn't want to ruin your day, I'll go elsewhere with my bright spark ideas, somewhere they NEED a man with ideas and the guts to try them out" so you won't be put in prison for upsetting the power company's monopoly. 

Best of luck and how about some photos?

[MAL]

in open water the Mississippi flows at about 5  MPH  or 440 FPM however near the shore at a distance of 30 ft this could be as low as 50 FPM and right next to the shore say 5 or 6 ft this could be azs low as 20 FPM or less depending on depth I know several places where it hardly moves at all .
 so the first thing is to determine the ft per minute rate near where you plane to install this device
 Remember a barrel has an approximation of 6 ft in circumference. your  floating circumference distance will be 2 times the radius from the center of the shaft to the surface of the water inn  inches  times 3.1416  divided by 12 to get feet divide this into the FPM flow rate to get free RPMs
to figure what size or how many paddles or how many barrels first you need to know what your gear ratio is going to be to spin your generator at the desired RPMs

Thanks for the info this will give me some where to start.  I can't measure the river speed right now, because there is ice, but I will play arround with the numbers.  5 mph sound about right, I have always been under the impression that current speed varies between 3 and 8 mph.   So for starters I will go with the worst case senerio at 3mph=264fpm.  I can't get an acurate floating circumference at the moment, but that number will be adjustable because I will have additional flotation on each end.  If I wind up with a 10''radius I will have 50.42 rpm's.  The next step for me is to decide what type of generaror to use.  After a breif search it looks like a generator head will need over 3000 rpm's, an alternator will need about 1800 rpm's or I could make my own generator with windings and magnets if that is the best option, but there would be a learning curve on that one if I chose that option.  I am open to suggestion on my sourse of electricity, but I am leaning toward an alternator on my first prototype because of cost and symplicity.  I have not found any information on the pro's an cons on these 3 alternatives.  Do you have any suggestions?

[Frank S]

Mal; the 5 MPH figure is mean channel current average and what is called clean water. Just like air water is subject to obstruction resistance disrupting laminar flow. this can create turbulence and even eddy currents creating pools flowing in reverse or in cases of large obstructions off shore leaving a choke channel leading back to the main body the flow rate can increase  to several times the river's natural speed.
 I know of one place in Arizona where the Verdi and the Salt rivers converge the main bodies may be running at 8 MPH certain times during the year but along the shore where there are boulder islands the rapids between them will be 2 times that speed other times during the year up to 3 or 4 times the actual convergence speed at the time. the only way you will know for sure how much the surface speed will be will mean you will have to (heave the log) to borrow a phrase from ancient mariners   

[MAL]

Yes, that all makes sence, but if I "heave the log" now it will bounce on the ice. I have lived at this location for 46yrs and have a good idea what the river is doing in front of my house.  The current in front of my home is very similar to the current in the channel, but probably a little slower.    For now all I can do is plan, engineer and learn about hydropower.  I have read/watched a lot about hydropower, but I haven't seen much at all about the advantages and disadvantages between a generator vs an alternator.  Is there a thread that explains the pros and cons of each?

[jlt]

I have played with a similar  design but the river running through my property is much smaller.

  I used several 6ft  4"x4" 6'  long pieces of wood daisy chained together. they had blades made from 1/8 aluminum and had 2 4blade sets on each piece of wood.  the first piece of wood had a 5ft section of hydraulic hose that was connected to the axial turbine.
    The axial turbine had a 15 inch rotor and 16 neo mags. and 12 coils and single rotor
At about 7mph you could not stop it from turning by holding onto the hydraulic hose. It only made about 40 watts.
 
I believe it was capable of a lot more but the rpms were to slow.

 If I had a better stream to work with I would still be trying to perfect it. The canal company takes almost all the water for irrigation in the summer time

[MAL]

Do you think building your own generator was the best way to go?

[Frank S]

determine what your target wattage requirement will be this will help you decide your course of action
If you know for an absolute fact you have say 5mph water or 440 fpm and a circumference length of 6 ft then you would have approximately 73 RPMs at  this speed you will either need a DIY generator with many poles or a gear up to get a decent RPM maybe both. There are many good home built generators on these forums but even those usually need  150 to 300 RPMs t0o produce any substantial amount of wattage.
 the re worked Delco based generators need several 100s of RPMS to do much good but if you can gear one up to around 1000 to 1800 RPMs most of the better built ones will produce 200 to 300 watts easy enough.
 There is a lot of power to be harnessed from moving water providing you can get the sizing of your paddle wheel set up correct

[MAL]

I will check the rivers flow when the ice clears.  I can say with some confidence that I have seen a wide range of current speed...right now, in the middle of a drought, I would guess it to be about 2mph, or in a flood I have seen as high as 15mph or so.  As a rule the flow is close to the average speed of the river, and is very consistant. 

My targeted wattage would have to be as much as possible.  The purpose of this project is to save money and be less dependant on the grid/(OFF).  With all that said it looks like I need to create as many rpms as I can. 

As it stands right now I probably average about 1000 kwh per month usage, but I dont know how to translate that to wattage.  I have noticed that whole house generators seem to start at 700 watts.  That is the purpose for my questions...to get some idea what to expect...where to start...which direction I shoud go...what has worked in the past.  I dont expect to get off the grid on the first try, but also I dont want to just throw money into a hole on a failed project.  You have been very helpfull, thanks 

[birdhouse]

As it stands right now I probably average about 1000 kwh per month usage, but I dont know how to translate that to wattage

1000watts is equal to 1Kw.  it's an instant type measurement.  now when you introduce time...  1000 watts being used for one hour equals 1Kwh (killo watt hour). 

now lets say you have something that draws 200w, and you run it for 5 hours, it will consume 1Kwh even though it's only drawing .2kw or 200w.   

lets take your 1000Kwh monthly usage, or 1000000wh.    that same 200w load would have to run for 5000 hours to use that much electricity. 

make sense? 

adam

[MAL]

Yes that makes sence, but I am still a little confused as to what size generator would run my home.  I don't expect to fully power my home with a few barrels in the river, but I am trying to understand what to expect from a generator and what size I need to shoot for.

[Frank S]

Yes that makes sence, but I am still a little confused as to what size generator would run my home.  I don't expect to fully power my home with a few barrels in the river, but I am trying to understand what to expect from a generator and what size I need to shoot for.

This is not all that easy to figure out without knowing peak usage.
1000 Kwh divided by 30 days would be 33.33 Kwh per day or 1.38 kwh per hour, but real time usage does not work that way. So either you would need a large bank of batteries + a generator capable of 1.5 kw continuous output or better.
 Get  one or more Kill A WATT meters and create a log of daily usage find out where you can reduce the load factor by staggering the usage  try to reduce the monthly totals by closely monitoring where you actually need energy and where you do not. get rid of as many parasitic loads as possible.
 Read Chris Olson's threads, He has wind solar battery & standby and runs a TOTAL electric home with the exception of heating, in a very severe cold climate.
 In your situation hydro would be a lot more stable than his wind but the concept is similar.
 Just remember he has a  unique custom designed system and has invested tons of money into it   

[thirteen]

I tried to find it but about 2 years ago someone on here made a floating water wheel and had it in a creek. It seemed to work ok. will you have a lot of junk floating into your barrels. In your house there are probably several items that burn electricity even tho they are not turned on. There insides continue to operate like the TV, computor, oven, dryer, empty beer frige in the man cave(HAHA). When I leave I have a power bar that I just reach over with my foot and shut off all the power to the things at my desk. We have a intertainment center and while I'm at home it gets shut off the way with 2 power strips, when I am gone the boys leave everything on and say it takes a long time to activate everything. Three months ago I gave them the power bill between 2 months and told them to pay the difference. They paid the whole thing and have not complained at all and they shut it off when they leave most of the time. So test your power usage and that will help. You may need to put a reflective tape on your barrels for people that cannot see while on the river. It is funny sort of when you get a Kill A Watt meter and discover where your power is going and where you are wasting money. From old friges to TV's to radios left plugged in nd not used. The biggest ones I found was the frige and the seldom used old TV in the back room. It was better to buy a new efficiant frige. It will take 2 years to pay for it's self in power savings.
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[MAL]

There will be some floating hazzards...high water can bring large trees ocasionally.  I shouldn't have much trouble with boats at my location.

[stratford4528]

If its of any interest I made an alternator that produced power at 12 revs per minuite. Only 40 watts but it did it at very low revs. I drove it direct with a 4ft water wheel. I broke it down to rebuild and make more efficient but never got round to doing it. If you could make something like it it saves gearing and transmission losses.

[marius]

hi, I am in the process of building a floating waterwheel, build on the frame of an old catamaran boat, floats nicely, channels the water to the paddle ( with a diameter of 150 cm(5ft) and will use pulleys to speed up the alternator, our stream flows at about 2m/sec, I hope to get 1kw for an investment of 3000 New Zealand dollars, will use it to heat our home during the winter as that would be the best constant use for us. marius.