How to quantify the abilities of a PMA before attatching it to the turbine.

[prepperquest]

Hello everyone,

I am new here so please allow me to introduce myself.

I am your neighbor from the NL. And I have been spooked a bit by the pandemic and wars breaking out around us and such.

So I thought it important to learn how to be self reliant.

So I took up (indoor) farming of nutrient dense produce like potatoes currently.

Also, since I could not find a commercially available wind I thought the only way forward was to build one my self yet I lacked the experience and knowledge on how to actually pull that off.

So I started crowd sourcing ideas on several fora like this one and we have gotten rather far in the meantime but as we are nearing the assembly of the alternator and the installation on the turbine we have a bit of uncertainty on how to proceed.

Please see the turbine spinning. It is rather mesmerizing

Anyway. What it is we are looking for is a way on how to quantify the limits of the coil and magnet configuration. I mean it would be a shame if we spend a lot of time and effort just building the PMA only to find it does next to nothing in practice.

Here is the alternator test bench and the stacked coils I believe are a good candidate for PMA building.

I have come to believe the way forward is using gravity and weights to test for torque on the alternator while all coils are shorted. But the details of how to actually do it are a bit unclear still.

Does anyone here have an idea on how to proceed?

I am surre I missed quite a bit of details that one might need to form a mental image of what is going on so please do not hesitate to ask for details yes?

Kind regards.

 

[Exfarmer]

Hate to say it but these type of turbines produce very little sadly. Many people have tried to improve on the design but with little joy

 

[prepperquest]

Sadly you are correct These drag types VAWTs are indeed the least efficient as far I am aware of at the moment.



But for me I do not dare going with lift type blades yet as that would bring safety concerns as then the blades would have to spin much faster. Around 4 times faster than the wind while these drag type blades spin at a Tip Speed Ratio of around 0.44 (44% of the wind speed)



Based on https://www.omnicalculator.com/ecology/wind-turbine

it should be possible to get somewhere near the 330 watts at 5m/s. It certainly is not much but at least I hope to be able to trickle charge my 48V battery bank (a Lifep04 16S array of cells)



In regards on how to quantify the PMA Permanent Magnet Alternator.

One idea is to use a weight and attach it tot he PMA test bench. And then measure the difference in time the weight takes to drop from a known height with the coils open circuit versus the coils short cirtuited.



But the conundrum then becomes what do we do now with this measurement of time? How can we get to units like watts as to make sure the PMA will not fry it self when a storm hits and we get 19m/s winds.



Or perhaps someone can suggest a totally different way of tackling this problem?

 

[rogeriko]

You need higher rpm to generate electricity. First purchase a commercial HWT that has been tested before you try to improve whats commercially available.

 

[prepperquest]

You need higher rpm to generate electricity. First purchase a commercial HWT that has been tested before you try to improve whats commercially available.

I am not sure I agree with you yet. But truth be told you might well be correct.

For example I can generate electricity with a single 0.4mm enameled copper wire wound in a single loop and then run it through a horse shoe magnet.

Now of course the potency will be next to nothing but I am making this remark to signal that I am no longer really clueless but that I think we should focus on the nuances of all matters concerned.

I can build an alternator that generates around 52vAC at around 4 RPM running at 3.7Hz. At least I still think I can. But how do we quantify it's power potential is the question at hand.

 

[prepperquest]

my earlier post in is still in limbo because of moderation aproval needed. It is probably because it had a link in it to a calculator that I use to predict some kind of output posibilities.

Sadly you are correct These drag types VAWTs are indeed the least efficient as far I am aware of at the moment.



But for me I do not dare going with lift type blades yet as that would bring safety concerns as then the blades would have to spin much faster. Around 4 times faster than the wind while these drag type blades spin at a Tip Speed Ratio of around 0.44 (44% of the wind speed)



t should be possible to get somewhere near the 330 watts at 5m/s. It certainly is not much but at least I hope to be able to trickle charge my 48V battery bank (a Lifep04 16S array of cells)



In regards on how to quantify the PMA Permanent Magnet Alternator.

One idea is to use a weight and attach it tot he PMA test bench. And then measure the difference in time the weight takes to drop from a known height with the coils open circuit versus the coils short cirtuited.



But the conundrum then becomes what do we do now with this measurement of time? How can we get to units like watts as to make sure the PMA will not fry it self when a storm hits and we get 19m/s winds.



Or perhaps someone can suggest a totally different way of tackling this problem?

 

[rogeriko]

This guy has made hundreds of turbines just like yours.

Hugh Piggott's blog | Scoraig Wind Electric News

The Piggott Turbine - Wind Empowerment

The Piggott Turbine Hugh Piggott’s A Wind Turbine Recipe Book gives a step by step guide for manufacturing a range of SWTs from 1.2-4.2m rotor diameter using only basic tools, techniques and materials. Figure 2‑5 shows the carving of blades from planks of wood and the grinding and welding of a...

windempowerment.org

https://www.youtube.com/user/scoraigwind

 

[prepperquest]

ok please ex use me for getting a little frustrated.

I have bought all his books and non of them contain the answer to my question.

Can we please just stay focused on the matter at hand?

 

[prepperquest]

ok please exsuse me for getting a little frustrated.

I have bought all his books and non of them contain the answer to my question.

Can we please just stay focused on the matter at hand?

 

[prepperquest]

you know what? to avoid us getting an emotional dissatisfactions between each other. I will bury this question here for now.


I would love to still talk about potatoes soon.

 

[prepperquest]

This guy has made hundreds of turbines just like yours.

Hugh Piggott's blog | Scoraig Wind Electric News

The Piggott Turbine - Wind Empowerment

The Piggott Turbine Hugh Piggott’s A Wind Turbine Recipe Book gives a step by step guide for manufacturing a range of SWTs from 1.2-4.2m rotor diameter using only basic tools, techniques and materials. Figure 2‑5 shows the carving of blades from planks of wood and the grinding and welding of a...

windempowerment.org

https://www.youtube.com/user/scoraigwind

So although MR. Piggott never build hundreds of a VAWT like ours and I have most books already. Basically making such statement not to the benefit of the community.

Please allow me to elaborate why that is.

You see that in the meantime we have finally arrived at a consensus on how to arrive at a clearly defined unit as to measure the power potential of a PMA.

So that means that I will continue building.

All will be open source of course so in case there be farmers with a rather large field and some unused corner then who knows it might be of benefit.

Now all I have left is a gazzilion questions on potatoes My go to prepper staple

 

[prepperquest]

@moderators, this thread may be closed and marked as solved in the meantime

 

[prepperquest]

You see that in the meantime we have finally arrived at a consensus on how to arrive at a clearly defined unit as to measure the power potential of a PMA.

*unit should be method

 

[prepperquest]

This guy has made hundreds of turbines just like yours.

Hugh Piggott's blog | Scoraig Wind Electric News

The Piggott Turbine - Wind Empowerment

The Piggott Turbine Hugh Piggott’s A Wind Turbine Recipe Book gives a step by step guide for manufacturing a range of SWTs from 1.2-4.2m rotor diameter using only basic tools, techniques and materials. Figure 2‑5 shows the carving of blades from planks of wood and the grinding and welding of a...

windempowerment.org

https://www.youtube.com/user/scoraigwind

So I have some updates to share should anyone be interested.

And Yes My Piggott NEVER build anything like this ever!!

Just to get a heads up if there is interest or not. Or indeed leave it at, in my scenario, potatoes.

 

[prepperquest]

the PMA is nearing completion

 

[prepperquest]

this is going at things from a complete new angle as opposed what is to be found in the books.

now I can already tell though that even at these insane dimensions and magnet count. it still would benefit power potential if one was to increase the rotational speed.

I will leave this as a cliffhanger for now just to gauge if there is interest in to the why. But I would be ecstatic to tell more about it