Water Wheel Powered Generator

Kinetic energy = mv²/2, in compatible units. For a low-head turbine/wheel, you might be able to capture 60% [??] of it. This can give an idea of how much flow is needed. (Fairly large undershot wheel, maybe?)

You don't mention a number of necessary bits of salient information needed to give you a detailed answer.

This stream, how deep is it at the place you want to place the water wheel?

Is the flow of water constant all year round?

What is the elevation of the "fall" of the stream?

What are the "seasonal" conditions? Does the stream ice up over winter?

The power you wish to extract (250V @ 750W) is it DC or AC?

Is there a constant demand for that power at that level?

Are you able to divert some of the stream via a pipe to drive the water wheel or are you planning to just put the wheel in the stream?

If you need the power to be constantly available, then consider using the waterwheel driven alternator to charge a battery bank, then use that power to drive an inverter to provide the "regulated" power.

kinetic energy of water flowing through 1 m2 is 1/2*m*v2 watts.the energy per M2 of your stream is 1/2*5*1.5*1.5*1000=3750watts.so you can use a water wheel of 1 m2 to extract power.the design depends upon foundation facility there.Wane type is preferable

Sorry to mention, but how did you manage to obtain 3750Watts with the formula & values you mentioned???? It does not compute even if you were correct, and you are not correct!

The OP did not even mention the volume of water going through at the mentioned speed (5 kph taken as 5 km per hour). If he ment 5 kg per hour then you will need either the elevation drop or the flow speed...

But, 750 = 1/2 * mass * v² replacing either the v or the m will enable you to get either the m (kg/s) or the speed (m/s). which might me computed to say that he needs ~100 L/s flow if 5km/h

(or if 5kg/h then a speed ~ 200m/s ???)

Which is which? ----> Paddle width, diametre of the wheel etc will come into the works.

Not too sure of your maths here. 5 kph is 1.39 m/s. 1 kg moving at 1.39 m/s has a kinetic energy of 0.5*1*1.39^2 = 0.97 J. The volume of water passing through an orifice in the stream of 1 m2 cross-section in 1 second is 1*1*1.39 m3 = 1390 kg. The power available, assuming 100% efficiency, from this flow is 1390*0.97 J/s or 1343 watts.

correction on above calculation.Area 1m2.velocity =5000m/3600s=1.3 m/s.Kinetic energy=1/2*1.3*1.3*1.3 =1.09*1000=1090 watts..60 percent energy can be drawn to generator=659 watts per meter sq area..Try to design the rotor based on this calculation.The rotor to develop 750w should have750/659=1.13M2.upon the depth and width of stream the type of water wheel design has to be selected.Please quote the stream depth and width.

In Northern California, I met a Truck Driver, that close to his cabin, he had a 6' wheel connected to a 10 speed Truck trans... He said the ratio was 40:1. to an Altinator for a Reefer. To Twelve D-9 Bateries ---- But his House was All 12 V. He also had a inverter / converter. // He also had a 3208 Cat engine. 6 Belts driveing 6 Altinators. to his Batteries. It was show room clasic!

If I haden't been surching for my Son... I would have stayed longer like he asked me to do. So I Could build a Grandfather Clock Generator for him. ( With a Quick Connect centrifical Wheel.)

A usable guide to find the potential electricity in Water, is, " flow in litres per second, times head in metres times the "gravitational acceleration," (informally called little g) which is roughly 9.8 (at sea level) for this guide, gives you power in Watts, which you then multiply by the efficiency of your hydro unit and conversions. Hydro units are usually approx. 60%, though some claim up to 70%. However in your situation, that will be very hard to ascertain, - as another poster suggested, an undershot wheel could extract the available energy, I guess you could try calculating the area of the blades that would be required, then build a small one to see how close your guess was. (:-)) Geoff Thomas.

If you need to increase the flow and pressure, install a pipe of a size that you feel is right for the amount of water you have. Then after 10 or 20 feet install a water ram it will increase the pressure which you run into a smaller pipe then into a pelton wheel box with two injectors (one on top and one on bottom) then relase water thru drain pipe back into stream.

This is the best one I have ever seen. Virtues...very simple. Easy to make. Very effective. Nearly maintenance free. Will not disturb fish or mess up the environment. Nearly impossible to jam.

Drawbacks...ummmm There must be some but darned if I can think of any.

Any efficiency numbers? Maximum rpm (or rph)? Would Tesla love it or not?

When you consider efficiency, do you consider the cost of building the dam, removing the silt from the reservoir, building fish "ladders" to somehow keep from disrupting migration patters and the years of turbidity you put into the water when you build a dam? Not to mention the environmental studies which might at any time put paid to so many mini-hydro electric projects! The Tesla Turbine of the type shown in the picture does not have any of that.

Well...if we just consider the turbine itself, the available energy you can pull out of a stream is about half as compared to "bucket" type (Pelton) turbines...Tesla claimed to be able to get up to 60%, with his turbines, other experimenters seem to be getting about 40%. But then, to put that into perspective, modern turbines seem to be running at efficiencies of slightly over 90%, BUT they chew up fish, get clogged with water weeds, and require a fair amount of mechanisms to keep "on track". Please note that although the picture really DOES show a tesla turbine that was adapted to a slow moving stream, they normally worked a little differently in that they had a central hole in each disk which would discharge water, and the water would be shot tangentially into the stacked disks...this substantially increases the efficiency of course. But...it starts to complicate things as well.

Another interesting note is the ease which it can be scaled up. A bucket type turbine is pretty much a one off in power in versus power out, and not very versatile outside of its rated range. If the water runs high in a flood, you cannot take advantage of it. A tesla turbine can be stacked, even on site, to take advantage of changing water currents and variable heads.

So, my take on this? I could make two or three tesla turbines for the effort and materials I would expend to make one pelton wheel. If all I had was a stream running past my shop, and especially if that stream had fish and kids swimming in it, or was full of benign CO2 eating water weeds, a low efficiency tesla turbine just like the one in the picture would work just fine. If it doesnt' turn the generator fast enough, well, I would just make it bigger to get more energy out of what I have.

(The tesla turbine was used for steam...its "runaway" (unloaded) speed was too great for the materials they had available in Tesla's day, so there is no doubt that it works. I made a tesla windmill last year out of old election signs. The results were mixed, but then, I don't think anything would work all that well in the freezing rain. Maybe if I had an incentive, like the OP...)

So yeah...Tesla would have loved it...a stream moving past at a walking pace...right up his alley!

Even an undershot wheel needs some 'ducting' to harness the available mass flow.

I'm afraid you need the rest of the Tesla turbine to get anywhere near the efficiency - in which case - the fish that make it through the high pressure nozzles, then get sliced.

However, I suspect you know full well the 'monument' is producing no power past perhaps turning itself and are just 'pulling the OP's leg'.

_{But for that GA, possibly indicating the OP is sucked in, I'd have let it go.}

It would be more interesting to see efficiency numbers for that particular turbine, rather than other generalities. There is a lot more material in that device than would be present in a simple paddle wheel. The channel in which it resides looks like low velocity, but the appearance is uncertain.

Maybe I'm going out on a limb, but I would bet that I could stop the rotation with my bare hands. What I see here is low torque combined with low rpm = low low power.

Lots of wheels are shown turning with no load but it's different when you put a load on them. You need more than 5 kph, you need volume, how much water is passing this point, is there any chance of damming this to get a head then control the flow to try to keep output steady.