Discuss Generator question? Will the load stipulate the amount of power needed to turn the gen shaft? in the Hyrdoelectric Power Forum area at ElectriciansForums.net

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Benburton12

So I'm about to install a generator in my back garden that has a turbine on it, i have a small river running in my back garden and I hope to harness the rivers kenetic energy, I was just wondering that when i connect my generator to a load such as a small light, will the shaft on the turbine become a bit harder to spin because doesn't the magnetic field in the generator increase as you add a load and will that but more resistance and strain on the shaft. Thank you.
 
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Benburton12

I'm new to this site and I thought I'd join so I can ask questions and help other people out too, thank you
 

telectrix

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you're right. he bigger the load, the harder the genny is to turn.as long as the water has enough force to power whatever load you're driving, it will work. imagine using your hand as a friction brake on the water wheel.the harder you brake it, the more work the water needs to do to turn the wheel.
 

ruston

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It will work the same way as an old wind mill , or pedalling a bike. the resistance of the movement will dictate the power required to do the work.
 
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Benburton12

It will work the same way as an old wind mill , or pedalling a bike. the resistance of the movement will dictate the power required to do the work.
Ahh right thank you for your answer I understand now, also another thing, I heard that all the generators in uk power stations all spins actually at the same time and cut though each magnet at the same time too, is this true or not, because the uk uses 50Hz and if generators don't spin at the same time then you would have didn't phases coming at different times.
 
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Benburton12

you're right. he bigger the load, the harder the genny is to turn.as long as the water has enough force to power whatever load you're driving, it will work. imagine using your hand as a friction brake on the water wheel.the harder you brake it, the more work the water needs to do to turn the wheel.
Thank you for your answer I understand now.
 

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You probably already know this but if you are going to use a wheel then water going over the wheel will give better results than water going under the wheel. Yes this may mean alterations to the water flow of the stream.
 

telectrix

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You probably already know this but if you are going to use a wheel then water going over the wheel will give better results than water going under the wheel. Yes this may mean alterations to the water flow of the stream.
could use the generator to power a motor to pump the water to the top of the wheel. :gru:
 
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Benburton12

You probably already know this but if you are going to use a wheel then water going over the wheel will give better results than water going under the wheel. Yes this may mean alterations to the water flow of the stream.
Cheers for that and it maybe a bit hard for me to make the water fall on top of the turbine because of way the river is because it's not deep enough you see, but I'll try my best.
 

Dan

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The struts holding it up aren't actually holding it up, it's flat I think. And a motor is spinning the wheel because it took a second or so to get up to speed.

Not sure where the water goes though.
 
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Benburton12

The struts holding it up aren't actually holding it up, it's flat I think. And a motor is spinning the wheel because it took a second or so to get up to speed.

Not sure where the water goes though.
Ahh right ok, cheers
 

snowhead

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Cheers for that and it maybe a bit hard for me to make the water fall on top of the turbine because of way the river is because it's not deep enough you see, but I'll try my best.
How about building a small Dam to lift the water level up, assuming you own the River?
 
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Benburton12

How about building a small Dam to lift the water level up, assuming you own the River?
Yea that's a good idea, but I'd probably have to redirect the river flow then build the dam then redirect the river flow back to the original place. And if I mess up the redirection of the river flow then my whole garden may flood.
 

Dan

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Yea that's a good idea, but I'd probably have to redirect the river flow then build the dam then redirect the river flow back to the original place. And if I mess up the redirection of the river flow then my whole garden may flood.
If you do do something make sure you take loads of pictures for us!
 

ruston

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If you have no fall to create a head of water , and you know that you can get a water wheel to work to some degree , depending on the power you require you could couple more than one wheel together to give the drive more torque .
 
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Benburton12

If you have no fall to create a head of water , and you know that you can get a water wheel to work to some degree , depending on the power you require you could couple more than one wheel together to give the drive more torque .
Ok cheers.
 

telectrix

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but don't drop the camera in the water unless it's one of these waterproof jobbies.
 
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Benburton12

If you do do something make sure you take loads of pictures for us!
Also when I read that guys thread, you know the one about the renewable energy, I think he was thinking that the compressed air tank would have to be already fully compressed before hand by just using normal mains power and then most of the work would be done by the compressed air rather then the motor, I think he would put a electronic device in the system that only required the motor to feed off the power of the battery only when the compressed air tank was like half empty, so that would give time for the battery to gain charge and then after the motor could feed off the battery for a few minutes or so then be automatically switches off. Maybe that was what he was thinking, I'm not sure, what do you think?
 

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Just as an aside, I presume you are aware of the EPA and LDA permissions required to install even a small hydro plant. ..... even if the stream is on your own land.
 
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Benburton12

Just as an aside, I presume you are aware of the EPA and LDA permissions required to install even a small hydro plant. ..... even if the stream is on your own land.
I am aware of something similar like that, but the river that runs through my back garden doesn't have fish or wild life in it so I thought I'll just install the generator and turbine without asking for permission because I don't want them to say no, fair enough if there was fish and other wild life in the river then I probably wouldn't think about putting any type of renewable energy system in place. But for now it's safe, I will be sure to clean all parts properly and make sure that the generator is ovisously water tight.
 

ruston

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You could also rig up a shaft drive and have the generator housed well away from the source. This will add to the losses , but if the river/stream is fast flowing with a good quantity of water you should be able to overcome this.
 
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Benburton12

You could also rig up a shaft drive and have the generator housed well away from the source. This will add to the losses , but if the river/stream is fast flowing with a good quantity of water you should be able to overcome this.
I'll think about it but thanks for the idea, it's just I don't want to spend too much money on it so that the pay back period is faster.
 

ruston

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I'll think about it but thanks for the idea, it's just I don't want to spend too much money on it so that the pay back period is faster.
It's difficult to give advice not knowing the situation , and your objectives . Good luck though, it sounds like a nice project.
 

Dan

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Just so others know what's gone on here. Ben and Ajay were the same person. But after several attempts at trying to get through to him to remove one of the accounts he carried on arguing with himself in the convo lol

Haven't got time for trolls so both accounts have gone.
 
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