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0.5kw hydro electric project

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MicrohydroBIGI

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Joined
May 17, 2024
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Hey guys i have been working on a hydro project here on the big island of hawaii for a fee months now have layed 1100ft of 2inch line with around 65ft of drop or so. I have gone through a handful of cheap chinese turbines so far and am on my third one as of now. The link to the turbine can be seen below.
MHJYD 300W 1000W 220V... https://www.amazon.com/dp/B09WYP8QWF?ref=ppx_pop_mob_ap_share

I have had issues with each turbine in power production. I assume based on my head and flow rate i should be producing anywhere from 0.3-0.6kw of electricity. Is this incorrect? When i test using a volt meter on the DC side of the rectifer im getting 273v and 0.61amps. Not much power correct? That was measured when hooking the dc leads of the rectifer to a 24v battery bank for just a moment. What charge controllers work with an input of 276v? How do i put a load on the turbine to see what my max power is with a voltage that high? Is it safe to charge 24v bank with that high of voltage or any long length of time, surely not?
 
You would probably do better with a gravity water wheel than an impulse turbine. Even with zero flow in the pipe, you have a maximum of 28PSI static pressure @ zero flow, but I suspect with friction you will have something less than 50gpm of flow, near zero pressure, and something less the 5fps velocity. I think there is more energy available using the weight of the water than would be available in an impulse turbine. This is based on 65' head and 1,100ft of standard 2" pipe.
 
Gold Country Russ said:
You would probably do better with a gravity water wheel than an impulse turbine. Even with zero flow in the pipe, you have a maximum of 28PSI static pressure @ zero flow, but I suspect with friction you will have something less than 50gpm of flow, near zero pressure, and something less the 5fps velocity. I think there is more energy available using the weight of the water than would be available in an impulse turbine. This is based on 65' head and 1,100ft of standard 2" pipe.
Click to expand...
Thanks russ! any calculators rolling around which i can double check that on. Based on volume of water i see coming out of pipe i would assume atleast 100gpm but im not positive.
 
First confirm the head by installing a 0-30 or 0-60 pressure gauge in the outlet end of the pipe, with the pipe full of water and the outlet closed, what is the pressure?
Next, weigh an empty 5-gallon plastic bucket. With water flowing thru the pipe, time how many seconds it takes to nearly fill the bucket. Reweigh the filled bucket, subtract the empty bucket weight, divide the remaining weight by 8.31, the result is gallons. Divide the result by the fill time in seconds. The result is gallons per second so X60 = GPM.
Exactly what type and size pipe is it? Any elbows or other restrictions?
 
Gold Country Russ said:
First confirm the head by installing a 0-30 or 0-60 pressure gauge in the outlet end of the pipe, with the pipe full of water and the outlet closed, what is the pressure?
Next, weigh an empty 5-gallon plastic bucket. With water flowing thru the pipe, time how many seconds it takes to nearly fill the bucket. Reweigh the filled bucket, subtract the empty bucket weight, divide the remaining weight by 8.31, the result is gallons. Divide the result by the fill time in seconds. The result is gallons per second so X60 = GPM.
Exactly what type and size pipe is it? Any elbows or other restrictions?
Click to expand...
Is pressure not always the same regardless of pipe friction? Isnt only flow rate affected by pipe friction? Before we go to micro urinal turbines id like to atleast make 100w @ 12v 😂

How am i supposed to get a correct amp reading if theres not much i can tie into the end of a 276v dc rectifier output? Any suggestions?
 
Last edited:
Gold Country Russ said:
First confirm the head by installing a 0-30 or 0-60 pressure gauge in the outlet end of the pipe, with the pipe full of water and the outlet closed, what is the pressure?
Next, weigh an empty 5-gallon plastic bucket. With water flowing thru the pipe, time how many seconds it takes to nearly fill the bucket. Reweigh the filled bucket, subtract the empty bucket weight, divide the remaining weight by 8.31, the result is gallons. Divide the result by the fill time in seconds. The result is gallons per second so X60 = GPM.
Exactly what type and size pipe is it? Any elbows or other restrictions?
Click to expand...
Its black roll pvc tied together with compression fittings, and no elbows its straight all the way. Theres 900ft of black roll and 200ft of white pvc in the middle with some T’s for fish ponds and what not but nothing restricting flow or drawing water at the moment.
 
MicrohydroBIGI said:
Is pressure not always the same regardless of pipe friction? Isnt only flow rate affected by pipe friction? Before we go to micro urinal turbines id like to atleast make 100w @ 12v 😂

How am i supposed to get a correct amp reading if theres not much i can tie into the end of a 276v dc rectifier output? Any suggestions?
Click to expand...
Pressure along the pipe is a function of vertical drop, pipe diameter, pipe roughness (Manning's "N" number) and flow rate. There are online calculators.

Lots of info online on best turbine configuration for head and flow rates available. Many impulse jet microturbines have multiple jets on valves so that you can tune the flow rate to the available water as the seasons change.

High head favours Pelton wheel type impulse turbines, low head favours Francis turbines or other similar "in water flow" devices.

Link to turbine type descriptions

Also note that there will be an optimum electrical load on the turbine to extract the most power for each flow rate/pressure point. To get data and find optimum loading, you could try loading the turbine output to various resistances with a series of 240V loads like hot water heater elements, resistive heaters, light bulbs etc.
 
Here's a good read from Home Power magazine. They were the print version of DIY solar and all things renewable not that many years ago.


1716056331231.png

100 GPM in 1100 ft of 2" Poly does not math out. 185' feet of friction loss says it's not possible to move that much water in a 2" pipe. To me it looks like you've either got more head or a lot less flow.

Here's that calculator. https://www.omnicalculator.com/physics/friction-loss

Just for fun we will use your 100 GPM and 65' of head. 65' x 100 / 12 = 541 watts

1716055977681.png
 
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OzSolar said:
Here's a good read from Home Power magazine. They were the print version of DIY solar and all things renewable not that many years ago.


View attachment 216172

100 GPM in 1100 ft of 2" Poly does not math out. 185' feet of friction loss say it's not possible to move that much water in a 2" pipe. To me it looks like you've either got more head or a lot less flow.

Here's that calculator. https://www.omnicalculator.com/physics/friction-loss

Just for fun we will use your 100 GPM and 65' of head. 65' x 100 / 12 = 541 watts

View attachment 216171
Click to expand...
2" pipe friction @ 50 gpm = .0537 per ft. x 1100 = 59.07 feet plus some for fittings so just about equal to the total head. At the outlet it should equalize at roughly 50GPM, zero pressure, and 4.78 feet per second velocity. The best way to make power with it, I'm pretty clueless.
 
Gold Country Russ said:
2" pipe friction @ 50 gpm = .0537 per ft. x 1100 = 59.07 feet plus some for fittings so just about equal to the total head. At the outlet it should equalize at roughly 50GPM, zero pressure, and 4.78 feet per second velocity. The best way to make power with it, I'm pretty clueless.
Click to expand...

On this page there are three videos demonstrating what im working with. I think you may be nearly right about the gpm i tested with 5gal bucket it seemed to be 1gal/sec, theres enough pressure to where the turbine spins and im unable to close pipe with my hand.
 
MicrohydroBIGI said:

On this page there are three videos demonstrating what im working with. I think you may be nearly right about the gpm i tested with 5gal bucket it seemed to be 1gal/sec, theres enough pressure to where the turbine spins and im unable to close pipe with my hand.
Click to expand...
MicrohydroBIGI said:

On this page there are three videos demonstrating what im working with. I think you may be nearly right about the gpm i tested with 5gal bucket it seemed to be 1gal/sec, theres enough pressure to where the turbine spins and im unable to close pipe with my hand.
Click to expand...
65' head Divided by 2.31 = 28.1 PSI X 3.14 sq. in. (area of 2" ID pipe) = 88lbs pressure required to stop flow.
 
Gold Country Russ said:
65' head Divided by 2.31 = 28.1 PSI X 3.14 sq. in. (area of 2" ID pipe) = 88lbs pressure required to stop flow.
Click to expand...
So do you think i have “near zero” or 28psi based on what you see and info? Somewhere inbetween? Feels closer to 28psi, 5ft/sec, 1gal/sec based on my stone-age bucket test. IF i do have that much pressure and flow, what should i expect coming out the other end and do you have any recommendations on what to load onto it to see?
 
Yes, it has 28psi at dead head, zero flow. But if you drill a hole in the side of the pipe a few inches above the outlet, tap it, and install a pressure gauge you will see near zero pressure when there is full flow. If you install a tiny nozzle to the end of the pipe it will have near 28PSI, the bigger the nozzle the less the pressure, all the way down to full flow (as restricted by pipe friction) with near zero pressure. To have any usable pressure you will need to restrict the flow to something less than full flow to reduce the pipe friction loss. With the flow reduced to 25GPM you would have 21PSI usable pressure.

That creek looks like a really fun place to play. Have fun with your experiments.
 
MicrohydroBIGI said:
I have gone through a handful of cheap chinese turbines so far and am on my third one as of now. The link to the turbine can be seen below.
MHJYD 300W 1000W 220V... https://www.amazon.com/dp/B09WYP8QWF?ref=ppx_pop_mob_ap_share
Click to expand...

I swear, that looks like the impeller for a vacuum cleaner.
Suspect it is much lower efficiency than one actually designed for hydro.

The toothed pully is also a sign of something repurposed.

First order of business is determining flow x pressure representing max power delivered, as Russ is guiding you through.

From pressure you can determine velocity of nozzle output. For a Pelton wheel, maximum power transfer when buckets move at 1/2 that velocity.
Select a turbine to support operating conditions. There should be some way to tune load to hit that RPM; one might be adjustable constant-voltage charge controller. Don't know if any MPPT do a good job for turbines.

Obviously much larger pipe would have worked better for the flow you want to use.
Depending on terrain, could divert and run in a ditch across hill, make shorter steeper run in pipe.
 
Hedges said:
I swear, that looks like the impeller for a vacuum cleaner.
Suspect it is much lower efficiency than one actually designed for hydro.

The toothed pully is also a sign of something repurposed.

First order of business is determining flow x pressure representing max power delivered, as Russ is guiding you through.

From pressure you can determine velocity of nozzle output. For a Pelton wheel, maximum power transfer when buckets move at 1/2 that velocity.
Select a turbine to support operating conditions. There should be some way to tune load to hit that RPM; one might be adjustable constant-voltage charge controller. Don't know if any MPPT do a good job for turbines.

Obviously much larger pipe would have worked better for the flow you want to use.
Depending on terrain, could divert and run in a ditch across hill, make shorter steeper run in pipe.
Click to expand...
Thanks , this thing came with a 1/2 inch nozzle. When running its making 276v dc just need a mppt that will go up that high so i can bring it down to my 12v system but i find nothing, do you guys know if any that do?
 
Hedges said:
I swear, that looks like the impeller for a vacuum cleaner.
Suspect it is much lower efficiency than one actually designed for hydro.

The toothed pully is also a sign of something repurposed.

First order of business is determining flow x pressure representing max power delivered, as Russ is guiding you through.

From pressure you can determine velocity of nozzle output. For a Pelton wheel, maximum power transfer when buckets move at 1/2 that velocity.
Select a turbine to support operating conditions. There should be some way to tune load to hit that RPM; one might be adjustable constant-voltage charge controller. Don't know if any MPPT do a good job for turbines.

Obviously much larger pipe would have worked better for the flow you want to use.
Depending on terrain, could divert and run in a ditch across hill, make shorter steeper run in pipe.
Click to expand...
Orginally the system came off a 15ft waterfall and fed some fish ponds, i added an extra 400ft of pipe on the top side of creek and another 300ft on the bottom side to run this project. The waterfall would be the place to divert more but its a an entire other project with drilling and rebar and concrete and placing a 4-8inch line along a cliff, one day. This was easiest most accessible option, and if i can get it to make 100+ watts @ 12v DC i will be pleased.
Why do they ship all these chinese wheels and turbines with these rectifiers? I do see its an easy to way to steady voltage but where does one go from there?
 
MicrohydroBIGI said:
Thanks , this thing came with a 1/2 inch nozzle. When running its making 276v dc just need a mppt that will go up that high so i can bring it down to my 12v system but i find nothing, do you guys know if any that do?
Click to expand...

Transformer. Is output 1 phase or 3 phase?
Variable taps or variac would let you adjust load.

Oh, rectifier? Tap in before that.

There are 150V, 200V, 250V Midnight Classics. Yours is a bit above that.
Sunny Boy 5000US series, has turbine mode, makes AC.
Either of those is multiple kW.

Any power supply, e.g. 240V fat snake for a PC, internally makes 360VDC then steps down. It can probably take DC in on its AC power pins. We did that with a power supply meant mounting in a chassis (even though it was PF corrected.) It is even the right size for your application.

 
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