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Posted

OK so I'm probably going to start an argument and or some may think I'm crazy but here goes

 

scenario Hypothetical

you have your pool working and from the pump outlet you have a inline hydro generator .

the  hydro generator   then supplies power which could be used to charge your batteries on your inverter

for argument sake lets  say you have a 1.1 kw pool pump, and we know that due to losses you cant  produce as much as you supply  but lets say you can

make 500w.

What say you

cheers

Posted

It's doable but keep in mind that it might cause some additional pressure on the pump. And, as per thermodynanic's first law "energy cannot be created or destroyed, but rather transferred or changed - whatever energy is captured by the hydro generator, will be lost elsewhere - possibly from the pump motor. i.e. the pump motor would most probably suddenly work harder than it would have without the hydro generator. 

Perhaps one way to get around this would be to have your outled higher up than the pool and rely on gravity to turn the hydro generator. But I suspect the pool pump might possiblt also work harders to push the water higher up? Perhaps, if you can, connect a wattmeter to the pool pump in such experiments. 

Posted

I agree with what you say but lets for argument sake say that the water that comes back into the pool anyway  now hits a hydro  wheel generator so almost nothing changes from the pump side. so absolute minimum change or strain on pump .

problem is where would you could you find a genie to do it .

but its makes for interesting thought

cheers

 

 

Posted
35 minutes ago, maxomill said:

I agree with what you say but lets for argument sake say that the water that comes back into the pool anyway  now hits a hydro  wheel generator so almost nothing changes from the pump side. so absolute minimum change or strain on pump .

problem is where would you could you find a genie to do it .

but its makes for interesting thought

cheers

 

 

What do you mean?

You need to purchase / build one ;)

Posted

http://www.hobbytronics.co.za/p/58/36v-micro-hydro-generator

One needs to that heed of Silver's observation.

I have a borehole that fills two reservoirs which then gravity feed my home providing about 4-5 bar of pressure. I can use one of these hydro generators to keep the irrigation system charged and still have 2-2.5 bar pressure to ensure the sprayers work properly.  

Addendum: This is a 3.6V  300mA unit so it it not going to save the world but it means I would not  have to power the irrigation unit when it is installed.

Posted

There was a guy here a few months ago trying to tell us that hydro systems are inefficient.After a lot of to-and-fro-ing, turns out he's argument is based on the speed at which the water exits the turbine. Your visual acuities tells you there's energy there! Trouble is, the law of the conservation of energy tells us it must all add up to zero. So if our turbine is 85% efficient, something we can calculate because we know the total amount of energy we start with (volume of water multiplied by how far it has to drop), then we know there is a maximum of 15% to be scavenged somehow, and we also know that we're going to get nowhere near 15% because if we do, we'll mysteriously see the efficiency on the turbine drop, probably as we start to create back pressure and what not.

So... same thing here. Kinda reminds me of how a car turbo captures the "waste" energy in the exhaust line... when it actually doesn't really do that, or to be precise, things are more complex. What the turbo does isn't to somehow find energy that wasn't there, what it does is increase the air-flow through the engine, and when you have more airflow you can inject more fuel while still keeping the mixture stoichiometrically correct, and so make more power with a smaller displacement. The total power, however, will still be a linear function of the amount of fuel you started with.

So my gut feeling about this... is that whatever you can reclaim is going to be low tens of watts... just a gut feeling though.

Posted

Another example, my new condensor tumble-dryer. What it does is pre-heat some of the inlet air with the hot outgoing air, and at the same time it condenses water out of the moist outgoing air with the incoming cold air. So it's being more efficient about this... but the kitchen/garage area is now much colder than it was, so if I had some kind of whole house heating (I don't) I would have seen the difference come out of that :-)

Posted
1 hour ago, Chris Hobson said:

http://www.hobbytronics.co.za/p/58/36v-micro-hydro-generator

One needs to that heed of Silver's observation.

I have a borehole that fills two reservoirs which then gravity feed my home providing about 4-5 bar of pressure. I can use one of these hydro generators to keep the irrigation system charged and still have 2-2.5 bar pressure to ensure the sprayers work properly.  

Addendum: This is a 3.6V  300mA unit so it it not going to save the world but it means I would not  have to power the irrigation unit when it is installed.

that's a bit small but a good example. A 500W turbine will cost about R16K. Not something I'm prepared to buy just to prove a point. IF, on the other hand I had a steady flow or water somewhere, it could well have been proven ;)

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