• Joe
  • Joe
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  • From: Cornwall
  • Registered: 2022-01-23
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Topic: Generate your own hydro power

For a few weeks I've been looking at all sorts of schemes to generate around 5kw of electricty. Along one boundry I have a stream 3m wide flowing at between 2-4 m/s. These are old numbers from the EA who used to have instrumentation on our property. I found some undershot waterwheel calcs online and these indicate about 0.6kw based on a 1200mm dia wheel with a blade size of 530 wide x 225 high.  The calc assumes one blade fully in the water at any one time.

I've come up with a new design of waterwheel where I can have say 7 or more blades in the water in a linear style, using the same sized wheel.  Does this mean that I can generate 7 x 0.6kw= 4,2kw or am I completely wrong?

Any help with this would be much appreciated.

I used to be indecisive, now I'm not so sure.
  • Registered: 2022-01-21
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Re: Generate your own hydro power

Is your design sort of like one of the tracks on a tank, but with panels below the track extending into the water, and then panels becoming pointing upwards in the air as the track goes back round in the air above the water?

William

  • Joe
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Re: Generate your own hydro power

Yes, that's it William. but the panels are hinged so they fall back when out of the water.

Joe

I used to be indecisive, now I'm not so sure.

4 Reply by jackneve (edited by jackneve 2022-02-18 17:33:38)

  • Registered: 2022-01-21
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Re: Generate your own hydro power

I wonder if it works like this. The first paddle uses the full force of the fall, ie uses all the potential energy available to one paddle.
(1) Maybe each of the 6 following paddles has the same potential energy usage, so you might get the 4kW.
(2) Maybe you would  get less usage of the 6 following paddles, ie, there may be less potential energy for them.

The first case seems quite likely.  You might want to make a model to try it before you go to the expense of a full size device.

The effect of a good outcome would be the same output voltage, but 7 times the available current, and hence power.

EDIT, Now I realise the paddles are probably not on the underside of an undershot wheel, and if they are in a straight line in a horizontal channel, then I don't think you would get the full power multiplication, as only one "slug" of water is  working. From the top of my head - not referenced to any data.

  • Registered: 2022-01-21
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Re: Generate your own hydro power

This might possibly be relevant.

https://en.wikipedia.org/wiki/Continuous_track

Joe's mention of the panels being hinged concerns me. The panel needs to get into the water.

I am wondering if the panel needs to be fixed firmly, with each panel having a piece of side wall along the side of the panel on each side, with the side wall piece wider near the track, and having a slope, each piece of side wall being like a trapezium. From a bird's eye view, each panel that in the air and its side wall pieces looking like a capital letter H. This being because the side walls and panel need to cut into the water like a diver in a diving contest.

A link to a video of a waterwheel.

https://www.youtube.com/watch?v=OPfjoAQxvcQ

William

  • Joe
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Re: Generate your own hydro power

Hi William,

Thanks for you interest.

The hinge effect would 90 degrees where the blade would fold back in the opposite direction of water flow only. It would continue to fold back even as it enters the water and present a minimal surface area. I do agree that having moving parts in this type of application is not the best.

On blade design I've used https://www.backwoodshome.com/design-ca … terwheels/ for the calcs and the paragraph at the end of the calculation explains a bit about the blade design.

Joe

I used to be indecisive, now I'm not so sure.
  • Registered: 2022-01-21
  • Posts: 382

Re: Generate your own hydro power

Off topic, but a useful information site linked by the backwoodshome site referenced in the previous post

https://www.backwoodshome.com/the-chole … -be-fatal/

It's about important precautions to prevent chimney fires in wood burning stoves, so common nowadays.

  • Alfred
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Re: Generate your own hydro power

jackneve wrote:

It's about important precautions to prevent chimney fires in wood burning stoves, so common nowadays.

I sincerely hope it’s the wood-burning stoves, not the chimney fires, that are “so common nowadays”!

"Has it ever struck you that life is all memory, except for the one present moment that goes by you so quick you hardly catch it going?"
― Tennessee Williams