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Join Date: Feb 2009
Posts: 9

water wheel

02/14/2009 8:00 PM

I have a 300 foot run, of one inch of water estimatied of a 60 foot elevation drop. And 24 foot water wheel. what will be the horse power of this be? An will it be sufficient enough to generate power to my house?

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#1

Re: water wheel

02/14/2009 8:04 PM

NEI

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#3
In reply to #1

Re: water wheel

02/15/2009 12:26 AM

And OP is wondering what NEI means.

OP will probably never be back to his/her own thread.

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#2

Re: water wheel

02/14/2009 8:33 PM

The theoretical maximum horsepower you can generate using a water wheel or water turbine is a function of the head and the volume. It has nothing to do with the size of your water wheel, per se, but only the energy represented by the falling water. This relation is:

HP = (H * CFM) / 540,

where

HP = Horsepower (1 HP = 745.7 Watts, to one decimal)

H = Head, in feet

CFM = Volume, in cubic feet per minute

You mentioned having a "... 300 foot run, one inch of water ..." Are these the dimensions and flow depth of a sluice/millrun? More info needed here, please.

What kind of water wheel do you have? Overshot? Impulse? Crossflow "turbine"? Pelton?

Note: The size of the water wheel determines your torque, not your power output. The head and the volume determine that.

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#4
In reply to #2

Re: water wheel

02/15/2009 12:01 PM

To begin with I understand your comment but if i have enough torque by using gear boxes and transducers i can run a pump back up to the source of water and gain more water flow; theoretically. I am not sure, all that is available is yet. As for more information part from the spring to the water wheel is 300 feet. From the spring height to the top of the water wheel is estimated to be about 60 feet. The one inch pipe water is the amount of volume flowing.

I appreciate your interest and reply I wish there was a way we could talk one on one. It sounds like you and I have the same thoughts going in the same direction.

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#5
In reply to #4

Re: water wheel

02/15/2009 4:58 PM

"if i have enough torque by using gear boxes and transducers i can run a pump back up to the source of water and gain more water flow."

Hi Mr. Thinker,

Have you considered using a larger pipe to move more volume, perhaps? A lot simpler, cheaper and less maintenance. And the power you'd use to run a pump would instead be available for your house.

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#6
In reply to #5

Re: water wheel

02/15/2009 10:06 PM

Yes ; I thought about putting in a swimming pool and use it as a reservoir,to hook up a pump in order to create a bigger flow of water. The only obstacle I had was , the law of nature says you never get more out than you put in. However there is more than one law of nature at work in this situation. Maybe that will make the difference, I'm not sure? I'm adding alot of cost. I also thought about using a four wheel drive transmission, that I have. I could hook it up to the drive axle of the water wheel and use the front drive shaft to operate a pump, while using the rear drive shaft to run A generator. Do you think that would work?

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#7
In reply to #6

Re: water wheel

02/16/2009 12:28 AM

Hello mrthinker:

Does this 1" water pipe come from a tap or is it part of a diverted water flow from a stream?

I have not worked it out because I do not know what is available for you to use.

The only obstacle I had was , the law of nature says you never get more out than you put in.

You are right. But you could also ad 'over time'. If you want this water to generate large amounts of power for very short periods, say driving an electric drill, that would work, after you have your reservoir built up. But as you say, you will only ever get the PE once. You can save it to a battery, but once you use it to power something it has gone. However, if it was possible to increase the constant flow to get enough to turn your wheel, then you may have something to work on.

It sounds to me that you mentioned the water wheel because it could possibly be more convenient than another supply and free!

The wheel needs enough to start it revolving, and the size of the wheel acts as a fly-wheel. But I can't ever see it moving with just a 1" flow.

If you are thinking about driving the wheel by using your car, I can see that may be on, but there is to many complications. You may as well go buy a generator to generate your power when you want and where you want it. It may be slightly more efficient and more 'reliable' than hooking a part of your car to a 24' ~ 8M water wheel. You will loose lots of power just turning the wheel and, I cannot ever see it being cost effective. Sorry and all that but I am working with the info you have given.

Water was driving the wheel originally, has the flow dried up, or been diverted, or was the sluice filled by a diverted stream in the first place? And why can you not divert enough to drive your wheel as you originally asked by water?

This sounds interesting and I would like you to keep in touch. But please do not attach your car to the wheel, OK? I doubt you would have a slow enough gear to turn the wheel. And the water was probably keeping the shaft of the water wheel cool as it flowed over. Running it using your car could rip the side of the build the wheel is on/in, out! Don't go there OK?

Good luck and take care. Any pics available?

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#10
In reply to #6

Re: water wheel

02/16/2009 1:03 AM

Hello mrthinker:

Is it possible to place the swiming pool or reservoir above the 60 ft drop in elevation ?? All hydro electric plants have the reservoir above the generators, water is stored in low electric needs and flow increased for higher demand times. !!

Cheers Gary

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#18
In reply to #6

Re: water wheel

02/16/2009 8:11 AM

" I thought about putting in a swimming pool and use it as a reservoir"

I wish I could do that! I could then copy a friend who uses the captured energy in his pool's temperature differential and heats his entire home in winter here in the North East. His energy bill for heating for the entire year was under $50 and that included the juice used to operate the heat exchanger pumps.

"I also thought about using a four wheel drive transmission"

I would try to avoid gearboxes and other intermediate devices in your power generation pursuit. Every time you do that you are loosing power.

L.J.

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#32
In reply to #4

Re: water wheel

02/17/2009 5:38 AM

Ever hear of TANSTAFL? There ain't no such thing as a free lunch? Any energy used to pump the water up the hill will cost you more energy than you can generate by the same water running down the hill.If this were not so, hydro electric dams would not need a river of water, only a low pond and a high pond and recirculate the water up the hill with pumps powered by the water going down hill. Walla! Perpetual motion! Insofar as generating electricity,you need to consider previous poster's information to calculate amount of power available.

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#8

Re: water wheel

02/16/2009 12:32 AM

As already mentioned you'll need the change in height (already known - 60 foots) and the volume of water per time.

Perhaps you could time how long it takes to fill a bucket/rubbish bin/swimming pool.

Knowing these two values it's easy to get the total available energy. Next step would be to estimate the losses in the water wheel, alternator etc and see if it's worth doing.

Sounds like it could be a great project

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#9

Re: water wheel

02/16/2009 12:48 AM

mrthinker --

From the Worthington Pump Water Data charts (some 50 years old) Table ET-1 the following head losses for water flowing through 100 feet of new 1" schedule 40 steel pipe (1.049 nominal inside diameter):

6 gpm, 2.68 ft. head; 8 gpm, 4.54 ft. head; 10 gpm, 6.86 ft. head; 12 gpm, 9.62 ft. head; 14 gpm, 12.8 ft. head; 16 gpm, 16.5 ft. head; 18 gpm, 20.6 ft head; 20 gpm, 25.1 ft head and for the purpose of one example calculation below 40 gpm, 95 ft. head.

You have a 300 foot run of pipe. Add 5 ft. of length to the calculation for every screwed 90 degree elbow; 29 ft. for every globe valve (gate valve are only about a foot, check valves 13 ft, most other ordinary pipe fittings 2 or 3 ft. each and maybe 1/4 ft. for each screwed pipe coupling).

Now if you open the end of the pipe and just let the water run on the ground the most you'll get out of the pipe is a around 40 gpm. Actually a bit less because some of that potential energy from the 60 feet head gets used up when the liquid goes from zero velocity hear the inlet up top to 13-14 feet /second where it squirts out at the bottom and the energy is lost. If the pipe ran straight down vertically that would be 60 feet. That would be a head loss through 62 ft. (remember three screwed couplings for three 20 foot lengths of pipe and a gate valve at the end so you can shut off the flow.)

But you have 300 feet of pipe plus some for fittings for a number like 305 ft. for the head loss calculation. And you get back the velocity head as long as the water stays inside a closed vessel like a water turbine off some sort.

OK you are going to want to figure the flow rate that will give you the most energy. (remember "head" is an energy number that really means foot-pounds per pound of fluid and the pounds cancel out leaving feet (ft.))

Now another thing in the US pump business that everyone used when we were still ignoring the metric system was the formula:

Head in ft. x gpm /3960 = horsepower (actual power transmission in the fluid).

A pump with 50% efficiency (typical of small centrifugal pumps driven by fractional HP motors) then would need a motor to put out 2 times that "fluid horsepower" to drive it. So a pump that would put out 19.8 gallons per minute at 100 feet head and 50% efficiency would need exactly 1.0 horsepower. Another point to make about centrifugal water pumps is that they can run with reverse flow as water turbines at about the same efficiency as they run as pumps.

Now let's take a look our energy source. The water has a potential energy content relative to your water wheel 60 feet below of 60 feet. (remember ft-lb. per lb of water) If you can get that water down to your water wheel or water turbine without and of that energy lost to friction that's great. But that would require a very big expensive pipe. You have proposed a 1" pipe and it will lose more energy the faster it flows. You have a number of possible flow rates and can calculate the head loss in pipe friction for each. Subtract this from 60ft (ignore the velocity head at this point, it's a second order effect), multiply by the flow rate and divide by 3960 to get fluid power in the liquid at the inlet to your water wheel. Plot this power versus flow rate (gpm) and you will get a curve which shows the flow rate for maximum power. This is the combination of head (ft.) and flow (gpm) that your water wheel or water turbine should operate. So select this machine based on its efficiency at this set of conditions.

Now let's look at our problem. Turns out that out maximum power comes at about 10 GPM and the head left after friction loss is about 39 feet. Ten times 390 and divided by 3960 is about 0.10 horsepower or about 75 watts. Now if we use a small centrifugal pump as a water turbine and it has about 50% then you'll have about 38 watts into your generator. Let's say you have a nice efficient little alternator off a motorcycle direct connected to your water turbine with a very efficient belt drive or direct. It will put out around 2-1/2 amps at 12 volts which will light a small lamp you can read with or charge a storage battery up in a day or so.

Does this answer your question? Bottom line is that if you want to generate serious electricity from water flow you will need a very large flow rate, usually orders of magnitude larger than that available (legally in many areas) to a homeowner.

If you can obtain the hardware and pipe at minimum cost you could probably supply a source of emergency power from a "self charging" battery until you tired of frequently cleaning the debris out of the strainer up at the inlet end. Better, assuming that you have rights to use the water, use the water for irrigating your garden and go get a small solar panel to charge the emergency battery.

Ed Weldon

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#11
In reply to #9

Re: water wheel

02/16/2009 1:43 AM

GA for calculations and the end result. After so many calculations and seeng the head and pipe size, the futility of doing the calculation was obvious (recently did it for the head loss in the pipe line but that was at least for some gardening or so).

But the GA goes for the calculations and the reply that will convince where none of the languages will suffice.

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#12
In reply to #9

Re: water wheel

02/16/2009 2:08 AM

This is not the first question on this aspect. People get carried away by the fact that a high head is available.

The parameter of interest is not the head - but the available energy - which is depending upon the flow. And a simple calculation of potential energy at source and the flow rate could have given the energy available at the lower level and multiply by the pipe line, generator and turbine losses.

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#13
In reply to #12

Re: water wheel

02/16/2009 2:53 AM

Thanks, sb, for the GA. I appreciate your patience wading through all my words. I really need to edit that all down to much fewer words since this type of question comes up so often.

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#14
In reply to #13

Re: water wheel

02/16/2009 4:42 AM

You are most welcome. Along with long lecture.

Next time anyone asks the same question I will refer to this link. /

Or psst...., dont tell any body I will cut the whole thing and paste in the reply, edit the values with algebraic x,y,z and get GAs .

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#20
In reply to #14

Re: water wheel

02/16/2009 8:49 AM

Hey sb! That gives me an idea (the only one I've had this morning): I'll create an alter-ego called "bs" who has a gremlin avatar facing the other way and then cut 'n' paste your posts along with solicitous requests for OTs.

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#23
In reply to #20

Re: water wheel

02/16/2009 11:07 AM

There is only one problem.

You have to rectify what-ever creative work I do with the thingies.

Are you upto the challenge ? remember it is us vs you (it is Gremlins )

And we will enter the tools you want to use

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#30
In reply to #20

Re: water wheel

02/17/2009 12:49 AM

Hey! This is all getting pretty high-handed!!! Are you sure you're all real hydraulic engineers???

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#31
In reply to #30

Re: water wheel

02/17/2009 2:05 AM

Engineers ? Who ? Gremlins ? Are you serious ?

PS: We do dabble in hydraulics (oil) but may be upto a few hundred bars only. Infact our steams are at a higher pressure (before we go out of steam let me tell you). else we are usually into power generation, only problem is our minimum hydels are a MW sizes

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#34
In reply to #20

Re: water wheel

02/18/2009 2:05 PM

You'll get your lardy-ass smacked one day.

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#15
In reply to #9

Re: water wheel

02/16/2009 7:03 AM

A GA for you, Sir Weldon

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#17
In reply to #9

Re: water wheel

02/16/2009 7:34 AM

Hello Ed,

Just gave you a GA. Very sound piece.

Take care...................

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#16

Re: water wheel

02/16/2009 7:15 AM

I have to agree with the above posts in that your flow would be very low with such a small pipe over such a long run. Using similar calculations to above, the max flow available would only be 1.2l/s with a 1" pipe, when the frictinal losses equal your total head. If possible would you be able to use larger pipes, as this would greatly increase the potential flow. A 2" pipe would max out at about 7.5l/s (~120Gal/min) and a 3" pipe at around 26l/s (400Gal/min). Obviosly these are relatively large flows of water and so it may not be at all possible to pull these flows from the source (bar using a resevoir as mentioned before).

However, even using these much larger flows the theoretical power (stealing the previous post formulas) would only be about 1.5kW, which is just about enough to run a small electric heater.

Just to give an idea of how much water is needed to create meaningful power; The Hoover dam has an peak flow of ~1,300,000l/s (or 20,000,000Gal/min) at ~500ft head, creating a peak output of ~2,000,000kW. By comparison, your 20Gal/min is a mere drop in the ocean.

All this aside, it still does sound like a fun project, that i'm sure would be enjoyable to work on. As for running your house off of this supply, i don't think that it would be possible.

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#19
In reply to #16

Re: water wheel

02/16/2009 8:39 AM

Hi, shanemcconn!

Welcome to CR4!

Good to see your well-thought-out answer to the OP. I hope to see lots more of you enyoing the action in here.

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#21

Re: water wheel

02/16/2009 9:15 AM

Hi, mrthinker!

Welcome to CR4!

Your question is interesting, and it looks like you're getting lots of action on it.

The concensus seems to be that your flow is too small to generate enough electricity to be useful to you. Also, that your pipe run to the waterfall is making the amount of power originally available from your source much less than it started out as being.

Even were that not so, the flow is quite small.

Are you operating from a well, or is there a definite spring source at the rop of your waterwheel's water source? If there is a spring, then the amount of water available might be more than just the 1" pipeful you can see/imagine flowing there. If there is more water available consider the following course of action.

If you owned one or more commercially made hydro generators made for home electricity consumption by people who have streams and waterfalls near their homes (you can locate them on the internet), you might be able to insert it in line at the beginning of the flow; or, if there is enough flow from the source for several of these tiny turbines in parallel or one or two in series, you might get something more useful out of it.

Rather than allowing the pipe outflow to run off into the air onto a water wheel, place a coffer dam around the source to capture as much of the upspring as possible. Rather than running a straight pipe to the edge of a drop, run your (screen-protected) pipes at an angle down from the source to near bottom of the waterfall drop. Before it gets into these pipeline(s) to the generator(s), allow the water to flow at source into a catch basin or holding tank, and on through the turbines in as immediate a sense as possible, and then let the water flow out of them into what's left of the little waterfall drop at the bottom. You might place outflow pipes at various heights of the tank (e.g. bottom, middle, top)to run more generators as the source flow changes over the course of the seasons. It's all according to what's available from the source and your operating budget.

A local geologist, geological engineer, or environmental engineer will let you know what you can drive with the flow you have; and the home hydro generator people will provide you with the right generator(s) to get the maximum amount of electricity from your source.

Mark

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#22

Re: water wheel

02/16/2009 10:13 AM

Hello, I got into this a few years back when a customer wanted a water wheel for appearance and to make power. I have a engineer friend that collects old engineering books and I asked him to see if he had information and would make a quote on calculating the gear ratio, HP, size of bucket on the wheel and basically design the wheel. He found a ton of information in a 1877 engineering book and after going over it his estimate for a basic design was over 40 man hours. There are so many variables that you have to take into consideration and the calculations that the 1870's engineers did was really impressive. First you need to decide if you want a over the top flow (over slung) or under flow (under slung) type of wheel. Then you need to figure out the size of the wheel and how many buckets it should have. This is where it really gets hard. if the buckets are to wide or large they will not have time to fill as the wheel turns and it will be to heavy. If you make them to small your water will run over and you will loose power. There are many other variables that needs to be addressed that I will not get into now. One thing I would suggest is to make the buckets as small as you can and set them in 2 " from the outside edge of your wheel so if the water over fills it will tend to run down into the next bucket. You should also put a small hole in the bottom of each bucket so that some of the water will run through to the next bucket. you then can adjust the size of the hole to let more water go through to the next bucket if you are over filling. An over slung water wheel is all about keeping as many of the buckets full as long as you can because the weight of the water is all that turns it. This is where the calculations get hard too because as the wheel turns each bucket will become lighter as the water empties out of it. On the other hand the under slung water wheel can be designed to use the head of the water to turn the wheel and they are more efficient. The wheel is designed more as a paddle wheel so the force of the water turns it instead of the only the weight. If you design the wheel to be enclosed sort of like a water turbine it will have more power but somewhat harder to fabricate IMO. Over all I had a great learning experience building the over slung wheel and it was truly a beautiful site to see it turning but due to lack of funding it never did make any electricity. One of the things that I found very hard to do was getting the wheel balanced and this is very important. I made my wheel from steel and we had a hard time finding a paint that would stay on it. I would also suggest that you use sealed pillow block bearings because the water will deteriorate the grease pretty quick. The customer I built the wheel for had a very nice stone wall built on the back side of his dam and had a curved stairway going down from each side to a bench in front of the wheel. I fabricated the wheel, formed and poured the concrete, installed the wheel, and then I set up a forge and anvil on site and built the curved handrails for the stairs leading down each side. In the end the customer had very nice looking working water wheel for around 15,000.00. If you are serious about building a wheel I would suggest that you first look for a engineering book from the 1870's because it will have chapters of information and calculations that will help you. Back then the water wheel was the choice of power for just about every type of industry so they had the design down to an art. One thing for sure is you are in for a learning experience and I would like to wish you Good luck.

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#24

Re: water wheel

02/16/2009 11:23 AM

I'd say pipewelder is on the right track. You do not have enough flow to get much of anything out of a paddle type water wheel, so you need to use buckets to increase force. In this case, head becomes irrelevant. Since gravity is the acceleration, f=ma is just f = weight of the bucket with water. Depending on your budget, you may decide to use more than one wheel where the higher wheel spills into the lower wheel.

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#25

Re: water wheel

02/16/2009 11:52 AM

I was looking at some prices for wind tubines from an old job we did here in the office and we were quoted €9,000 for a full install of a 1.3kW wind turbine. Now that will usually only give you 1/3 of its rated output (so around ~450W).

So if you could up the pipe size (and therefore your flow) you could get a meaningfull amount of power out of it, at least compared to a €9,000 wind turbine. To really get our teeth into your potential power, we would really need some acurate info on your water wheel ,ie bucket volume, amount of buckets, bucket design, overall water wheel design (over/under) and also on your water source, ie. max flow available from the water source, consistency of water source and ability to remove used water after the water wheel.

Once you have all that info it will be clearer what your max power and/or options are.

I also definatly agree with trying to source an old engineering book on water wheels (watermills) or hydrulics.

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#26

Re: water wheel

02/16/2009 12:48 PM

HI

I design and install micro-hydro and solar for a living. As stated above, a 1' pipe is not enough to pass a useful amount of water. If you up your pipe size, and have the available flow, a 3" or 4" pipe can pass 100 gpm(US) without much friction loss. This equates to about .6kVA of power production at 60 feet of effective head. With a battery system this is 14.4kVA/day of power production. Enough to run an energy efficient home. If your trying to convert this to HP (less than 1 horse) for direct power consumption, you'll be disappointed. At this volume you need a way to collect the power throughout the day... as in batteries. ES&D, Harris and a few others make pretty efficient micro-hydro units for this purpose. Also, if you are over-producing power throughout the day you can run a pump as a diversion load and send water back up to a storage resevoir for future energy production. Hope this helps.

C.Deacon

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#27
In reply to #26

Re: water wheel

02/16/2009 7:59 PM

Lighthasmass --- GA for you. Real numbers from people who do this to buy groceries.

What manufacturer's water turbines or water wheels do you like to use?

Ed Weldon

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#28
In reply to #27

Re: water wheel

02/16/2009 8:45 PM

Mr. Weldon - I default to ES&D out of Canada. They were the first to use brush-less alternators and I haven't had any problems with them. Harris also makes a good unit, and is comparable to ES&D now that they have switched to a brush-less design. Alternative Machine and Power out of Grants Pass, Oregon custom makes units and have run reliably in the systems I've installed. These are all DC generators and have a limit of about 2kVA. Apparently Harris has a unit rated to 3.5kVA but I don't have any first-hand knowledge of it. I've also worked on larger systems with AC units made by Canyon Industries out of Demming, Washington. Their units are custom and range up to 350kVA. Chris Deacon.

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#29
In reply to #26

Re: water wheel

02/16/2009 11:40 PM

hello lighthasmass:

Thanks for your input, as you do it to earn a crust! I think he would be better off planting some pretty flowers in the wheel boxes and getting a generator!

Take care....................

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#33

Re: water wheel

02/17/2009 4:57 PM
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#35

Re: water wheel

02/22/2009 9:45 AM

Hello mrthinker,

The drop you mention supplies sufficient head for a micro hydro turbine generator, however the flow rate in litres per second will determine the wattage output.

Good luck in your venture.

Peter

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#36

Re: water wheel

03/01/2009 9:58 PM

My in laws live on an organic farm off the electrical grid. a local installed and made a pelton wheel with 4 table spoons, 4 small water jets, motorcycle alternator, dodge mechanical voltage regulator. this ran through 250 feet of 14/2 house wire into a cpu controlled batt charger / ac to dc inverter. I think the dodge voltage regulator sits at the tool shed at the batt charger end. I believe the mcycle alt puts out 26 or 36 volts ac. the 1 inch line has a head of about 22 feet from small pond to water jet / spoon setup. distance of water line is about 550 feet. they phoned me and asked in advance if it would work and i said no way. I was wrong. it does and has since 1991.

the solar cells / smashed and broken glass top layer and deformed punctured bottom layer was given free. these 2 sol panels can detect [charge?] when a full moon is out. this is also hooked in through inverter charger. this is charging 8 [?] gel cell batteries. there is also a 50 year old elctric wall heater [1500 watts ?] hanging exposed by the batteries as a energy dump in case the batteries are full and water wheel and solar cells are still charging with no load from the house or barn.important!

unfortunately lightning hit and took out the very expensive charger / inverter and they had to replace. [3000 watts continous/ 5000 peak ?]

water wheel is about 6 or 7 inches in diameter with spoons attached. i don't know how many spoons to attach to a 24 foot water wheel. just kidding.

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#37
In reply to #36

Re: water wheel

03/04/2009 8:06 PM

I want to thank you for hope for what i want to do. if it were possible, would you be interested in helping me with this project? I don't know were you are located at but we are in Pa. I have an idea, waiting for your response.

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#38

Re: water wheel

03/05/2009 1:25 AM

I would love to help. I will contact my in laws and anyone else who has know how. I live 300 feet from Vancouver BC, Canada.[Burnaby] info coming asap.

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#39

Re: water wheel

03/24/2009 12:38 AM

I got a hold of my inlaws. the charger / inverter is made by "EnerMaxer".

The best resource for you is " www.energyalternatives.ca/ [according to inlaws]

go to " micro turbine courses". please read the customer testimonials before deciding to join courses or send money to anyone anywhere. a 24 foot wheel is not a micro hydro turbine though some useful information may be found there. I see there is a "design, troubleshooting, and Faq sections.

Inlaws also recommended "Pauls power house" but I couldnt find anything.

I found out tonight that the motor cycle alternator didn't work at first. A local had custom rewound or plain repaired the windings. don't know which.

there are some formulas somewhere that will grind out useful data. I just don't know where right now. ? Is the water wheel an undershoot or an overshoot ? over the top of the wheel down or towards the wheel and down on a smaller footprint of radius with water loaded in bucket ?

the one I had seen long ago rotated about 12 rpm. this then may require a speed increaser. pulley belts or gearbox.

I recommend lightening protection [inverter/chargers/solar panels] and I haven't got a clue about that or know any one that does. leaving friday [mar 27]for a week. hope this helps. these people know a lot more than I or anyone else I know. keep us posted please.

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