Energy Matters Forums

[mikef]

It is an interesting setup there. One of the issues faced is that you can not rely on water pulling more than 11 metres of head down a pipe after which the weight of the water causes a vacuume to form in the pipe. So removing that suction component by producing power instead of wasting that energy is worthwhile.

In a backyard pool this is not a factor hence we can utilize the energy of the water falling to minimize the input from the pump.

[Smurf1976]

A bit of info on the system in Tas that I mentioned. Note that the concrete building in the photo, really is the actual power station. It's basically just a concrete tube housing the machinery, so designed because it is right at the water's edge on Great Lake (into which water is discharged) so as to make maximum use of the available head. You can see the lake itself in the background at the lower right of the picture.

To the best of my knowledge, this would be the oldest example of recovering energy from pumping in Australia. Maybe there's something else somewhere else, but not that I'm aware of. This one has been in use for 45 years (and Great Lake itself has been used for power generation since 1916).

http://www.hydro.com.au/system/files/do ... Sheets.pdf

[gyro]

Hi Fellas
I am currently purchasing the bits for my micro-hydro setup! I have a small stream alongside my home that has a steady flow of water for most of the year but not enough to run Archimedes screw type generator full time so here is what I propose to do. There is only about 1 metre of fall from the dam so I intend to raise this by 500mm to 1.5 metres the water flows downhill to the pipes under the road so if I trench this to the dam I should be able to increase the head a little as well. In the top of the dam I am going to insert a 300mm PVC storm water pipe and inside of it the Archimedes screw generator to supply 48 volts DC from permanent magnet motor/generator. At the end of the pipe I intend to instal a water wheel with rare earth magnets fitted at the extremity of the wheel and a coil to collect the pulses as it turns. This way I get 2 soursces of energy 1 from the water wheel when water is at slow flow 2 from the Archimedes screw generator during rainy days.
I would like however some information if possible? how many turns and what gauge copper wire do I need in my coil to collect up to 10 amps at 48 to 55 volts from passing magnets and do I need laminated core?
Regards
Tony

[Tracker]

So yes, you can recover wasted energy under some circumstances. But it's not likely to be a workable situation at home.

and that is the real issue...

It IS possible and practical, if the cost of implementing is zero.. It's really only academic.!

One should ONLY run the pool filter when needed , or you are an environmental-vandal.
Running the filter to make power, is gross stupidity !

Even the thought of setting up a recyclable-micro-hydro (excess PV to pump), is likely crazy, as the volume required to be viable, would mean that the costs of the upper and lower tanks , could NEVER be recovered, unless you have 50K tanks sitting around..
..
.

[Gordon-Loomberah]

If your turbine is very good at extracting the energy from a very low head source (1.5m), you would need over 60 litres of water per second to get to 500W output. If this screw is near the top of the pipe as I think you are proposing, say 0.5m head, then you are going to need ~200litres/sec down that 300mm pipe.
Water wheels were recently discussed in another thread, there is not a lot of power to be had from them unless they are quite large and you have a good flow.

All I can say is good luck trying to make that all work!

[Tracker]

I would like however some information if possible? how many turns and what gauge copper wire do I need in my coil to collect up to 10 amps at 48 to 55 volts from passing magnets and do I need laminated core?

Not sure that ANYONE could tell you that as there are just too many unknowns.. like how strong are the magnets.. Were I in your shoes, then I would be looking for a Fisher-Paykel washer and remove the motor and bearings.. You could then experiment with the phase connection of the windings and see what you can get.
Even if you strip it and rewire the poles totally, , I can't imagine any better way to start..

With that original question.. There are U-Tube clips from those who have documented what they did. I remember trawling through them ages ago

" and do I need laminated core?" The designs that I saw, just use coils.. I think the issue with laminated cores is that they "restrain" the magnets.
It would be fairly simple to have three disks - two fixed with embedded coils and one with the spinning magnets, between. (see U-Tube)

I think that I wrote something ages ago about recovering the parts from a washing machine, for DIY wind turbines.. Search for Fisher Paykel or did I call it FingPaykel...

PS - In designing an Screw generator, I would think that you should be looking at how a Jet-Turbine works, with directing blades etc. to increase the applied force.. eg.. Have a system of Revolving-Fixed-revolving-fixed Blades.. Gordon, might have a better idea..
..
.

[lantern]

You could try going to the "Powerspout" web site and fill in the questionnaire. They mess with Ficher & Paykel
rotors.

[Tracker]

http://www.powerspout.com/

What a good find - At least it shows how a practical system can be produced.
You can also see that you could add more inputs and increase the power (and water consumption)
..
.

[gyro]

Hi Fellas
Thanks for the info I am presently having the Archimedes screw made out of 1.6mm stainless steel with 100mm pitch 6 flights my calculations are that with the tube full at 1 metre of head I can get just over 10 horsepower which is somewhat too much for my 600 watt generator so I will lift the end on a float to acheive a consitant 600 watts regardless of the amount of water available at any given time. I have done some experimenting with the Fischer-Paykel motor and find it needs too much torque because it is rated at 7.5 horsepower at 240 VAC 3 phases. The water wheel may have up to 32 rare earth manets 30mm diameter controlled by IC so that energy is only extracted from wheel in sets of 4 (eg: at very low flow only 4 magnets are used and as flow increases speeding the wheel up the IC will add 4 magnets each speed increase to create more drag and at the same time increase output transversely as the water volume drops) I will be building the water wheel from Marine Ply 10mm which will be fireglassed over with a couple of coats of resin over the mangnets to prevent them rusting up. In flood situations the the top of the dam will cantilever downwards over the Micro-hydro system protecting it from heavy floating debris and reset itself back up when water levels return to safe levels.