Restoring a historic watermill in the Italian Alps and putting it back into action. Help welcome!

Hi all!
Like I mentioned in my previous post, we’ve recently come to purchase an old watermill (in the state of being rebuilt) sitting atop a 6000 m2 terrain. We are planning to rebuild it, and it would be a dream to get the mill back to running again! We are by no means experts on hydropower, or even engineers for that matter. So we are learning as much as we can while we’re moving along with the build. At this point we want to asses how viable it would be to produce electricity with the waterwheel. Any help from you guys is much appreciated.

Edit: since I’m discussing my larger plans for the homestead as well below, I’ve added the thread to the homestead forum as well. Hope that’s ok!

First a bit of info on the history of the mill (you can skip this part if you’re more interested in going straight into the more practical stuff) The old mill has been there for at least a hundred years, but we haven’t been able to track the history of the site yet. The valley was known for featuring many mills as it is very rich in water, so the site could have featured a mill dating back a lot more then 100 years. I’d love to dig into the archives to find out more about the history. The donkey trail that runs alongside the border of our domain is called —loosely translated— the mill trail, and there is an old water fountain near the mill which has the engraving that translates to ‘mill borough/ mill village’. It is said that there used to be 6 mills running alongside the small river that flows trough our garden, but after a huge storm in the ‘60 swept away the roads leading to the mills, and many people were switching from agricultural occupations to working in the growing industries anyway, many of the mills were left to deteriorate and never to be rebuilt again. Our mill is the only one of the 6 that has survived, although much of the original structure was in ruins as well. Most of the ruined living quarters had to be torn down, and have been currently rebuilt by the previous owner using brick walls instead of the original stone walls, and a new roof has been put up.

Fortunately the original structures for the mill have survived, which means that there is an underground channel running underneath the house where the water used to flow trough after it had passed the waterwheel. We also still have the original structure in which the wheel was mounted, and the ramp from which the water was thrown onto the wheel. Now we heard that at some point in the history of the mill, they made the change from waterwheel to turbine, and we can still see the original tube that was used for this purpose as well. Unfortunately the original constructors build part of the house on top of the old turbine room, so we have no idea where the tube goes into (if it goes anywhere at all), and what is still left of the old turbine itself. We would have to break open part of the pavement and walls to see what, if anything, is still left. The only thing we know of the turbine tube is that it leads to some kind of basin, because if we pour water down in it, we can hear it falling into water, instead of hitting dry ground.

Onto the practical aspect then:
Currently there is a functioning wood/metal water wheel, that has been built by the previous owner some 10 years back (since he too dreamt of restoring the mill). Originally the wheel was powered by the river that runs through the domain. On the top border of the domain there is a waterfall of about 3,5/4 meters high, with the river then flowing steadily trough our garden before dropping off another 4m waterfall down into the valley. We believe the original mill tapped of the stream of water at the point of the highest waterfall, channeling it in a wooden aquaduct until it reached the mill, where it could either be drained into a channel flowing directly into the river below if the wheel is in need of maintaince (the original stone channel is still visible, but in need of repair), or it could be dropped onto the waterwheel. I haven’t measured the exact drop yet, but based on the photos I’m guessing a drop of at least 3 meters. Ideally we would like to hook the wheel back up to the original source, but in order to do that we unfortunately first have to get the permits to deviate part the original flow of the river (which in Italy can be a challenge).

Right now however the wheel is driven by a natural water source that originates about 30 m higher than the mill, and which has been channeled into a tube leading to the house. While there is a steady flow of water all year round, the current system is prone to blockage of the tubes due to there not being a decent filter system in place, leading to sediment washing into the tubes with heavy rainfall. The flow that eventually reaches the waterwheel is also slowed down because the water is first lead to the lower part of the house, where it could provide water for the makeshift kitchen, before it reaches a basin above the wheel via the principal of communicating vessels. The overflow of that vessel is what currently is being run onto the waterwheel (but which is making the wheel run backwards, instead of using an overhead flow). Despite the current system being rather make-shift, the previous owner and our current contractor claimed that -when the tubes are cleared out-, they put a dynamo onto the turning wheel and they had calculated they could produce up to 3KW. To me this seems very optimistic, but then again, even the slightest trickle seems to move the wheel at a decent speed (they used ball bearings for the axle, while the old wheels used to be greased steel on steel), and I’m no engineer so they could be telling the truth.

Now my question to you would be the following (I actually have several questions):
-Does the current output of 3 KW seem realistic to you? Is it worth improving the current system and if so, how?
-Is it worth the extra investment and kafkaësk struggle to get the wheel attached to the original water source (the river), to optimise the capacity of the wheel?
-How can I calculate the capacity of the wheel with the current system vs with the hypothetical system of connecting it to the waterfall?

I know I need to use the head and flow to calculate this, but it is a bit unclear to me at what point I need to calculate the head:
-is it the drop of the highest point in the mill structure onto the wheel (about 3,5 m)
-is it the height from the waterfall where I would be deviating the water until the wheel (about 5 m)
-is it the height where the river starts flowing until it reaches the mill (potentially about 500m)

What I know right now is the following:
-I’ve got a steady flow all year round (about 1,5 more in winter then in summer though), and the river never dries up.
-The wheel currently has a diameter of about 2,5 meters, but it is clear from the old mill structure that it used to house a bigger wheel.

Any input would be much appreciated! I’d love to keep you guys updated on the progress of the mill and I am happy to provide more photographs if anyone is interested!

Wow S; Way cool!  If I was nearby I would have to come help.
The turbine that they buried has my interest. It must have been not working for them to give up on it.
I have to think that a turbine would produce more power easier, than gearing off the waterwheel.
Building a flume from the waterfall to the wheel would be quite a project.  If you do, that is where you would measure the head from.

Was this mill used strictly for power or was it grinding grain?
The black pipe sticking out of the ground, supply's drinking water to the home as well as excess that spins the wheel backwards?

Looking at the whole project. I have to ask what your objective is.  
Are you looking to make all your power for the house? Is that all or do you have other ideas?
The water wheel alone is beautiful ! And spinning with water splashing it would be very picturesque.
Is that your thought ? I'm pretty sure you are not wanting to grind grain.

Your water has potential to make all the power you could ever want.
Piping it to a permanent magnet alternator or even better an A/C turbine and then letting the waste water spill over your wheel could be an option. The wheel would spin but your power would not be reliant on gearing.
To utilize the wheel itself, would require chains and or gearing. It would be hazardous to be standing near.

No matter what you are working towards we want to see! Please keep us posted with photo's of your progress.
   

Hi Thomas, thank you so much for replying!

I have many goals for our domain. Garden of Eden would be a good description. Just kidding though!
No we would love to make the domain as self sufficient as possible. We do not intend to earn money from the land itself, as we both have jobs we intend to keep. Both my husband and I are somewhat digital nomads. We both work from home, wherever that may be, on our computer. So as long as we have internet connection we can work wherever we want.
This is on of the reasons we were able to purchase the land as cheaply as we did. There is no asphalt road leading up to the house, there is an old stone mule path wide enough to get a small car up there, but it is rather steep, so we just park the car down to where the asphalt road is and walk the rest of the way. No biggie if you both work at home anyways and almost never have to leave the house. But for most people that have to commute to their jobs daily, it’s a lot less appealing I guess.

So our goal would be to keep our jobs to fund the project until it is somewhat completed and paying for itself. We hope to be able to produce as much as possible in the future (water, food, electricity) so we have to spend less money on those thinks, and thus have to work a lot less to earn said money. Ideally graduating towards both only working a few days in the week leaving the rest of our time to spend with kids/ working the land.

As for the water: we have two springs on our land that seep from the ground/ rock faces. We will get the water tested to see if it is drinkable. We’ve heard tales that one of the springs used to be used by the farmers when passing with their mules to drink, so we’ve got our hopes up.

Next up is the food: we want to grow a vegetable garden/food forest. Probably not a conventional veggie garden because our steep terrain and narrow terraces don’t allow for that kind of farming. We will probably be mixed plants, letting things grow up and around trees etc to use the space optimally. I’m currently planning a fruit orchard/ veggie patch combo on one of my slopes. You can read about it and give your two cents here: Transforming a heavy clay slope
We intend to keep a small flock of chickens, ducks and geese, for eggs and to use them to clear the soil and fertilise it. We’re not yet decided if we want to use them for meat as well. We don’t eat a lot of it.
We’ve both completed a year-long course to keep bees, and hope to do so in the future as well. We don’t have any practical experience yet though, just the theoretical.

As for the electricity and heating of our house:
We plan to heat the house using a combo of an air-to-air heat pump and wood stoves.
We plan to install a few solar panels for the first years. They will probably not be sufficient to power the whole household, but we’re hoping they cover the heat pump.
Ultimately we want to produce electricity with the water we have, to supplement the solar panels, which should hopefully be enough to power everything ( but we’ll have to play the long game to get this up and running decently. Italian laws are a maze) We can still attach ourselves to the power grid so we have that as a backup in the meantime.

The original mill was used for grain. The region was known for it. We spoke to the old owner today and he mentioned the turbine being installed in the early 1900. So the original grain mill part must be much older. The main reason we suspect they abandoned the turbine is because of the huge storm in the ‘60 that devastated an already economically unstable region. They also built a large hydro dam at the lake down the valley after the 60’ in an attempt to improve the region. Most likely the mill got damaged in the storm and given that the hydro dam could produce the electricity at a much higher rate then our little mill, it probably wasn’t worth while to invest any more into the restoration of it.

The turbine system is no longer functional. We have no idea what exactly is buried beneath our house, but it would cost us a ton of money to find out, as flooring is already put in place. In any case we were told it wasn’t worth anything anymore, which is why they didn’t bother. The previous owner was also keen on producing energy with the water so I believe him when he says it wasn’t a viable option. I have some pictures of the turbine tube though, so I can share them if they interest you.

The black pipe is attached to a tube system that lets us either direct the water flow into the house, or direct it towards the wheel. We cannot have both running at the same time. If we can reattach the mill to the waterfall, we can then maybe use the cleaner spring water exclusively for the house.

But I’m a big dreamer, so maybe all of this is much more than we can ever handle. But we’ll see! Dreaming doesn’t cost a dime.

thomas rubino wrote:

Your water has potential to make all the power you could ever want.
Piping it to a permanent magnet alternator or even better an A/C turbine and then letting the waste water spill over your wheel could be an option. The wheel would spin but your power would not be reliant on gearing.
To utilize the wheel itself, would require chains and or gearing. It would be hazardous to be standing near.
   

Do you have any experience on the matter? It sounds like you know what you’re talking about. I have no knowledge of producing electricity with water at all. Only what I’ve been able to pick up these last few months.
Any and all insights you could give me would be greatly appreciated! If you need more info from my end, just holler!

Edit: I see from your profile that you do indeed have experience with hydro power! I’d love to pick your brain someday!

Hi S;  Thank you for the thoughtful reply!
How nice you can work from home in such a beautiful location.
You are correct, in that dreaming is free! I think,that if we stop dreaming its is time to move on.

Since you are in a dreamy kind of mind let me add some extra things for you guys to ponder.
I'll start with my favorite... heating.  Are you aware of rocket mass heaters?  They are improving all the time as new innovations are revealed.
I suggest you might like looking at our RMH forum here at Permies and then you might be interested in this site http://batchrocket.eu/  This is Peter Bergs site. He is one of the foremost innovators of batchbox style RMH.  A more efficient and user friendly style of RMH than the traditional RMH.

Now let me suggest a few things with your water.
If possible  leave the existing pipe system in place and after testing, use it exclusively for household / farm use.
For power I'm going to suggest a completely new system.
And I certainly hear you about rules and regulations that must be followed.
I do not know the distances from your waterfall or how much fall might be involved. Cost could be prohibitive, of course so could building a flume.
New flexible pipe (black poly pipe) could be run above ground from the waterfall, exclusively for power.
Running water does not freeze so no need to dig in your rocks and clay.  even building a flume would require support posts somehow buried in rock...  
The thing about hydro is, volume is everything! Pressure is good as well.
But if you can flow enough water and have a way to discharge that water (you do) you can make more power with modern electronics than you would ever need.

I won't ramble on, just some food for thought.
I will mention that I have been 100% of grid with solar and micro hydro since 1983.

Hi Thomas,
Thanks so much for your insights so far.

I have considered rocket stoves. They actually traditionally build similar kind of stoves here if I understand correctly, but with ceramic tiles instead. Although as of right now it doesn’t look like we’ve got sufficient space for it or ideal chimney situation. But that’s a topic for another thread!

As for the water:
The distance from the waterfall until the top of the watermill should be about 150 feet, but I’m guessing here. I would have to go back and measure it more precisely.
As for the height difference from the fall to the head of the watermill: probably about 7 feet, and then another 9 feet from the watermill head until the water hits the wheel.

However the height difference from the waterfall until the lowest point of our domain is up to 55 feet. But that’s a distance of at least 500 feet

You can see a map of the terrain attached. I’ve marked the waterfall with a blue arrow.  The red arrow indicates the wheel. The blue dotted line is where the original channel was to connect the wheel to the waterfall. The red X marks the lowest point on the map.

Could you explain more about why it wouldn’t be a good idea to use the wheel to produce energy?
We don’t have a big budget and the wheel is already there and functioning. Creating a completely new turbine system might be above our budget, even if it produces more energy.
How much did you pay for your system? And how much do you produce with it?
Edited to add: It’s so awesome that you’ve been living of the grid for so long! Very inspiring!

Hi S;
Lets talk about the water wheel and why I think it is not the best option to produce power.
The original wheel was much larger, its purpose was to grind grain. It turned slow and had tremendous torque. That wheel and the grist mill are long gone.
The previous owner built the new wheel ? Its purpose was to make power ? Correct? Or was it more for the look?  
Do you know if he had further plans ? Like how to transfer from slow to fast ? Was he wanting to store power in battery's? Or produce on site A/C power?
Those are questions you must ask yourself.

In order to make power, we must spin a generator/ alternator.   Either an A/C unit or a Permanent magnet D/C . The faster it spins the more power it can make.
To use the water wheel we must know the rpm's of the main shaft (lets guess 400) and then calculate how to take  that 400 rpm and gear it up to a higher rpm. This will require motorcycle sprockets  and chain and will be trial and error (expensive)   It also would  be hazardous/ noisy to be near.  This can and has been done.

To go more modern we would use poly pipe to bring water to a pelton / turgo  type wheel. Spinning either a D/C alternator or an A/C generator.  Closed water system, always moving. Waste water falls below the hydro unit to return to the spring. Waste water could fall on water wheel to make it spin, would be very picturesque.  Very clean safe unit. No spinning gears and chains to get caught up in or break.

The real question is how badly do you want to go off grid? You are already hooked up. Could you sell /trade power back to the power company ?  
In the US, power company's will only buy back power gained from solar or wind. They do not have to buy power from a small hydro.

Going off the electric grid is a commitment. Costs can add up fast.  
Battery's are the weakest link and the highest repeat expense.  Invertor's , charge control's , solar panels and many more things  will be needed.

I have no experience with making A/C power. Costs could be much lower and the existing house wiring could be connected to.

So, have I peeked your interest ? Or bummed you out completely?
The reality's / costs of going off grid are high but so are the rewards.
It's a personal choice.  

Hi Thomas,

Thanks again for your insights.
To answer your question: you have both peaked my interest and bummed me out at the same time.
Honestly I'm just confused. Our current contractor (and friend of the previous owner) stated confidently that they calculated they could get 3KW of power, only with the current system (which is a weak system) by putting a dynamo on the main shaft. Using the much better flow of the waterfall should only increase this number. Only last week he re-affirmed that it would be a very low investment and basically easy-peasy to hook up a system to let the wheel generate power. Maybe not enough for the whole household, but a nice supplement none-the-less. He did not specify what system he had in mind to do this (he kept repeating the word dynamo), but I suppose both my lack of knowledge on hydro power and the language-barrier between us (I'm still learning Italian), doesn't help in this matter. I specifically asked him if his system would be a dangerous/ noisy one, and his answer was a definitive no (like waving his arms no and laughing at the silliness of my question), which seems to contradict your statement on the wheel system being noisy/dangerous.
So after reading your comments I'm starting to get the feeling that either our contractor isn't being honest to us, or that he simply has no idea what he is talking about (or using our money for his fun experiment). I don't know what's worse.
Third option would be that you guys are speaking about a different kind of system, and the system he has in mind is somehow simpler /safer? I'm going to try and get as much info as I can out of our contractor to get a better idea of what method he had in mind.
Given my limited knowledge on the matter: what kind of information do I need to try to acquire from him, to value if his idea is worth anything or if it's bullocks? Feel free to point out any questions I would need to ask him.

As for your turbine system. We have spoken about a similar system with our contractor as well. But he mentioned a cost of about at least 12.000 to 34.000 dollar to get permits and get it installed.
Do you have any insight on how much a system like the one you mentioned could cost us?

We are currently not yet attached to the grid. But we have the possibility to do so if need be (although it would cost us about 3.200 dollar to do so).
We greatly value the idea to be off the grid, but it does need to remain somewhat cost-effective. The whole point (or at least a large part of it) of us wanting to be self-sufficient is so we have to work less (earn less money) to be able to live. Ofcourse just the fact of being off the grid is worth something in itself, but there is also our financial reality, so if being off the grid would drain our bank-accounts faster than just taking power from the grid would, then it would just not be sustainable for us.
We are willing to make a decent investment in setting up a system that produces our own energy, BUT only if that system can start to pay itself back in a certain period of time by saving us money on the long run.
There could be the option of selling our self-produced energy, but as I understand it, they pay very little for it in Italy. Perhaps you can earn 500-800 dollars a year from it. Unless you have a highly efficient system that can produce a ton of electricity, but I can image the permits needed for this will cost a ton as well.
So I just want to focus on researching if there is a cost effective system that can produce just enough for our own household (or decently supplement it). No need for us to produce more than we can use.

From a romantic point of view (I know, I'm sorry!), I would prefer to do so by using our wheel, but if it turns out that it's not a viable route, I'm willing to consider a closed turbine system.
As for the solar panels, we are most likely obligated by law to have at least two units (green law in the country).

I'd love to hear your thoughts on this, Thomas! In any case thanks already for the time you've invested to read and reply to my story so far.

Hi S;
I would be interested in what system the previous owner is referring to.    It is possible there is something still available in Italy/Europe that has not been allowed in the US in many years.
My experience is all with pelton wheels and closed systems.

This is Wikipedia's description of a DYNAMO  
( A dynamo is an obsolete electrical generator that creates direct current using a commutator. Dynamos were the first electrical generators capable of delivering power for industry, and the foundation upon which many other later electric-power conversion devices were based, including the electric motor, the alternating-current alternator, and the rotary converter. Today, the simpler alternator dominates large scale power generation, for efficiency, reliability and cost reasons. A dynamo has the disadvantages of a mechanical commutator. Also, converting alternating to direct current using power rectification devices is effective and usually economical.Wikipedia)

A dynamo is probably what is under your floor. If so, they used water to spin it, not the water wheel. Hmmm? But it's easy peasy to hook up this new one ?
If such a generator is  available , how would you drive it ?  A direct couple to the shaft of the water wheel?  Would it work on low RPM's.
The description says direct current,if it is applicable. You would need a whole off grid system to use DC. Not that that is bad, just expensive.

Lets try to work up some questions to attempt to ask your contractor, so we might have a better idea what they are referring to.
We need to know a lot more about the "Dynamo". Most important, is where do you buy one ? If we can contact the manufacturer they will have solid specs we can work with.
We need to know is it A/C or D/C .   What are the rpm requirements? Is it a narrow power band or does it just keep making more power the faster it spins?
What is the cost ??? That's a biggie!
Ask to see his calculations on how they came up with 3kw . He must know the specs on this "dynamo" to calculate that number.
Ask him what RPM your shaft is turning. (if he doesn't know, that's a bad sign)
Ask him , if battery's are needed with this system.  That will tell us A/C or D/C.
Ask if there is another "system" like this nearby that you could inspect?

I'm sure there is more we could ask him. I realize the language barrier is tough to work around.
As far as the Italian government rules and permits and what they cost ... your on your own there. Or at the mercy of local officials.
Cost of equipment in Italy could be radically different than what is available here. So any cost estimates would be skewed.
Here is a link to the hydro I use.  http://harrishydro.biz/  His site will give you an idea of hydro costs over here.
Here is a link to my local off grid store .  https://www.backwoodssolar.com/

What I am thinking of as a system, (here) should cost less than $3000.  That is not counting all the off grid extras, just piping and the hydro.  
Depending on the parameters you could spend $10,000 more buying battery's and all the other things needed.  I am trying to estimate high.

Hi Thomas,

Thanks so much for this! You have no idea how helpful this is!
I will take your questions, translate them and then fire them at the contractor. I'll get back to you as soon as I have a response.

Interesting design challenge you have. I’ll be blunt and to the point but I have good news. But first forget generating electricity from the waterwheel!. It looks good the way it is. Ive gone over and over the subject with a expert and it’s not worth doing power from waterwheels!  Minuscule amount of power are generated. Big disappointment, you've been misled though likely not intentionally. Lots of people wishfully think lots of power can be generated from a waterwheel. I did lol.
If you need or want electricity to live there I think you have great low head pick hydro potential!!. The lower waterfall is 13.28 feet. That enough head. This type of hydro is a small investment and might not need permits at all. The water is falling over the waterfall anyway. Combined with a few solar panels you can run a small homestead. For about $1000 a small low head picohydro can be installed. Maybe have one on the upper and lower waterfall??  
Thomas is spot on that the system costs can add up. But if the picohydro works then you’re battery can be much smaller than if using solar panels alone. That’s a big savings. I would try some cheap inverters and charge controllers and have about $3000 in everything including batteries. Then if the government says to remove it I would get more solar panels and put the low head hydro back as soon as they leave lol.
Have fun playing in the water. If I was nearer I’d help. It’s a great site.

Jeremy Baker wrote:Interesting design challenge you have. I’ll be blunt and to the point but I have good news. But first forget generating electricity from the waterwheel!. It looks good the way it is. Ive gone over and over the subject with a expert and it’s not worth doing power from waterwheels!  Minuscule amount of power are generated. Big disappointment, you've been misled though likely not intentionally. Lots of people wishfully think lots of power can be generated from a waterwheel. I did lol.
If you need or want electricity to live there I think you have great low head pick hydro potential!!. The lower waterfall is 13.28 feet. That enough head. This type of hydro is a small investment and might not need permits at all. The water is falling over the waterfall anyway. Combined with a few solar panels you can run a small homestead. For about $1000 a small low head picohydro can be installed. Maybe have one on the upper and lower waterfall??  
Thomas is spot on that the system costs can add up. But if the picohydro works then you’re battery can be much smaller than if using solar panels alone. That’s a big savings. I would try some cheap inverters and charge controllers and have about $3000 in everything including batteries. Then if the government says to remove it I would get more solar panels and put the low head hydro back as soon as they leave lol.
Have fun playing in the water. If I was nearer I’d help. It’s a great site.

Thanks for being blunt! No use in beating around the bushes if I'm living on false hopes and dreams otherwise!
So about that picohydro: do you know of any good companies that produce these? And is it possible to install these ourselves without much electrical knowledge?
You say a picohydro needs a smaller battery. Am i correct in understanding the reason for this is because there is more electricity being produced constantly by the picohydro, while the solars only produce during the day/ sunny weather, so less need to store energy in a battery? Or is there another reason for this?

Hey Jeremy;  
I agree with you about the water wheel. They sure are pretty though! And theirs is already there in place!  I would dump hydro waste water on it just to make it turn!
Adding as many solar panels as you can afford is always a good idea.
I do Know the costs run a bit more than your estimates.   A 4 nozzle permanent magnet hydro is over $2000 here. Battery's can be easily that much or more.
No matter the cost though, the site has massive hydro potential.
It also can be hooked into the grid if they prefer the convenience. Like here, selling back to the power company just isn't worth the grief.

Check out this video. It shows how easy it is to start a syphon using this piping setup. And the turbine has potential. It needs to be improved, the fan blade is weak and will probably break. But it’s a great start. If it can be perfected there is massive potential for these low head hydro turbines worldwide.
https://youtu.be/1KyL1-0A0Gw
The low price is if I did it mostly myself DIY and with some salvaged and used equipment. Yes, I understand a multi nozzle turbine with a big and long penstock costs much more money than what I’m referring to.

this looks like a lot of fun. I agree with the others: water wheels are beautiful and have a lovely nostalgic effect. they aren't the best for maximizing your power, though.

55 feet is a lot of head. a bigger pipe will have smaller head loss, though it will also be more expensive and difficult to work with. avoiding sharp bends will also help. if you want to calculate this stuff exactly, you can do it with the Darcy-Weisbach equation and a Moody Diagram. the Hazen-Williams equation is quite a bit easier and probably more than accurate enough for your purposes.

in case you don't have enough dreams already, consider direct power, too: https://www.lowtechmagazine.com/2013/08/direct-hydropower.html

There’s a Italian hydro seller on eBay for years. They are selling a interesting low head unit currently that looks interesting. I’d need to do further study to see if it’s a good unit for the site:
https://www.ebay.com/itm/micro-hydro-turbina-banki-low-head-cross-flow-generatore-idroelettrico/254324348523?hash=item3b36e9966b:g:xbYAAOSwEgZZiMFy

Another thought is one of these Chinese units sourcing water after the waterwheel then down to the lower waterfall. If you can get over 7 meters of head it might work decently:
https://www.ebay.com/itm/500W-Micro-Hydro-Water-Turbine-Generator-Hydroelectric-Magnet-Full-Copper-Core/174009375556?hash=item2883c45b44:g:hu0AAOSwpJRdylw-

I found the Stream Engine I was thinking about when I first responded. This one takes a lot of flow. Have you done a flow measurement yet?:
https://microhydropower.com/our-products/low-head-stream-engine/
Enjoy

tel jetson wrote:this looks like a lot of fun. I agree with the others: water wheels are beautiful and have a lovely nostalgic effect. they aren't the best for maximizing your power, though.

55 feet is a lot of head. a bigger pipe will have smaller head loss, though it will also be more expensive and difficult to work with. avoiding sharp bends will also help. if you want to calculate this stuff exactly, you can do it with the Darcy-Weisbach equation and a Moody Diagram. the Hazen-Williams equation is quite a bit easier and probably more than accurate enough for your purposes.

in case you don't have enough dreams already, consider direct power, too: https://www.lowtechmagazine.com/2013/08/direct-hydropower.html

Any chance you could help me crack the numbers on that calculation? Could you perhaps explain what variables I’d need to measure in this situation, so I can take them as exactly as possible next time I go out to the site.

As for your link to the direct hydro power: I did consider that option if hydro-electricity turned out to be a dud. In fact I was considering powering a pottery wheel with it if nothing else was possible. I throw a decent pot!
The shaft of the wheel comes out into an area that needs to be used as a living space, so we can use a small area to dedicate to some sort of use for the wheel, but we can’t install a sawmill for example.

Jeremy Baker wrote:There’s a Italian hydro seller on eBay for years. They are selling a interesting low head unit currently that looks interesting. I’d need to do further study to see if it’s a good unit for the site
This one takes a lot of flow. Have you done a flow measurement yet?:
https://microhydropower.com/our-products/low-head-stream-engine/
Enjoy

I haven’t done the flow measurement yet, as I’m not exactly sure how to do it. For example: Do I take the entire volume of water that passes the waterfall, or just a part of that water? I’m fairly certain the Italian government would not allow me to divert the entire flow anyway.

Thanks so much for the links to the retailers. I’d be very greatfull if you could give me your opinion on the Italian one if you could study it. I will try to find out whatever I can about it as well in the meantime. Maybe there are reviews or I can get in touch with someone who has bought the unit.

Certainly can look into the low head Banksi turbine some more, And I can even ask a local expert who will be here tomorrow. It’s always good to crunch the numbers as well. [Head times flow divided by 10, IIRC]. I better check that equation to be sure it’s correct one to use for the estimate.
For a small stream the 5 gallon bucket method is way to count how many seconds for the bucket to fill. Do it a few times and average the results. Also do it at the lowest flow of the year and the highest flow of the year. Mainly the lowest flow is what limits your power potential.
The waterfall can make it easier to test the flow. If it’s a big stream place a barrel at the bottom of the waterfall and try to get the flow channeled into it then count the seconds for it to fill. If it’s a small stream a bucket works.
High head potential can be calculated at the same time using the flow and head data. If you can determine closely how many feet drop there is. Ive use a carpenter level and sighted down it before to get a rough idea.
Enjoy

Thanks so much for that info! I will go back next weekend go get those measurements (then do the flow one again during summer when the river is lowest).
I’ll get back to you shortly!

Here’s the other company I was trying to remember. They even have hydro power units from old mill sites I noticed in the products page:
https://www.powerpal.com/products.html

A 3kW system will operate 24/7 and generate 72kWH per day or 26MWH per year.
Thats 7 times the average European usuage. https://www.odyssee-mure.eu/publications/efficiency-by-sector/households/electricity-consumption-dwelling.html

But maybe the designer meant 3KWH per day which is only 125W per hour.


I wonder what the theoretical maximum power that is available.
Power = 0.2 x Flow x Head, where Flow=100gallon/min and Head = 150ft
Power = 0.2 x 100gpm x 150ft
Power = 0.2 x 15000W
Power = 3000W
or P = 9.8 x Flow x Head = 9.8 x 6.3liters/sec x 47meter about 3000W
There is going to be pipe loss, and turbine loss, generator loss; maybe 50% loss, so overall efficiency of 50%

Net Power = Max Power * efficiency
Net Power = 3000W * 0.5
Net Power = 1500W

Maybe the local guy already factored in the 50% power loss and your flow rate is actually 200gpm or 12.6L/s
Looking forward to getting actual flow and head info.

I have faith in the local guy being able to extra the energy from the water. With gears and extensions you might end up with more wear and tear and replacements but I think he will be able to extra the energy, even if I personally would have went with a different setup.

Hi Bengi,

Thanks for your comment.
I will try to go out to the property on Saturday to take the head and flow measurements.
As for the system put in place by the old owner, I will get in touch with him and the contractor to try and determine more accurately what their plan was, with the use of the questions Thomas Rubino so kindly proposed.
As soon as I have new info, I will post it here on the thread!

S. Bard wrote:Any chance you could help me crack the numbers on that calculation? Could you perhaps explain what variables I’d need to measure in this situation, so I can take them as exactly as possible next time I go out to the site.

sure. might have to dig my hydraulics textbook out, but I'll give it a shot when I find a few minutes.

S. Bard wrote:As for your link to the direct hydro power: I did consider that option if hydro-electricity turned out to be a dud. In fact I was considering powering a pottery wheel with it if nothing else was possible. I throw a decent pot!
The shaft of the wheel comes out into an area that needs to be used as a living space, so we can use a small area to dedicate to some sort of use for the wheel, but we can’t install a sawmill for example.

it should be relatively simple to use the same turbine for electricity generation and mechanical power if you ever want to go that route. your turbine will take up much less space than the water wheel, so you'll have much more flexibility for placement.

which reminds me: if you want to maximize hydro resource, consider putting your turbine toward the lowest part of your property. there are obviously some advantages to having it near or in the existing house, so you may not choose to put it elsewhere. it's at least worth considering.

Hi everyone,

Thanks so much for your input so far.
While waiting to go back out to the property to take measurements, I've drawn up this map to give you a better overview of how the site works. Pardon the ugly drawing, distances are not super accurate, but they do give an idea of where things are positioned relatively to one another.
I also added a top view map to give you more realistic sense of distances.

I was originally thinking the high waterfall would be the best spot to plant a turbine, if we were to go for that angle. But rethinking it, I'm wondering if the water coming from the spring on the highest point of our property might be a good option too.
The flow of the creek water is much higher than that of the spring, but the spring has a much larger head (9 feet for the waterfall vs probably at least 30 feet for the spring). These measurements are not precise though, which is why I'm going back there Saturday to take precise head and flow measurements.
The flow of the spring might still be improved, as currently not all of the water is being directed into the tube.
The places where the switches are marked are the spots where they put covers so we can reach the tubes and work on them for maintenance.
I've also marked the lowest spot on our property, but as you can see, it is very far from the house. And it's going to be difficult to dispose of the water at that point, as the road would need to be crossed to get it to flow back into the river.

I'd love to hear your thoughts on it!

I love the extra diagrams. It helped my to understand your site even better.
Below are some possible made up scenarios that are going thru my head, maybe they will help you to see how much power you could generate

Case1
Head = High Waterfall to Mill
Head = 3.5m + 5m + 2.5m (Waterfall + drop on property + diameter of mill)
Max Power = 0.2 x Head x Flow
= 0.2 x (11m * 3ft/m) x Flow (the bolded Flow is just my random guesstimation)  
= 0.2 x 33ft x Flow
= 0.2 x 33ft x 300gpm
=1,980W

Case2
Head = High Waterfall to Lowest Point on Property
Max Power = 0.2 x Head x Flow
= 0.2 X (Case1 Head + 20m drop to lowest point) X Flow (the bolded Flow&Drop is just my random guesstimation)
= 0.2 x [(11m x 3ft/m) + (20m x 3ft/m)] x Flow
= 0.2 x 93ft x Flow
= 0.2 x 93ft x 300gpm
=5,580W

Case3
Head = Spring to Mill
Head = 30m
Max Power = 0.2 x Head x Flow
= 0.2 x (30m x 3ft/m) x Flow (the bolded Flow is just my random guesstimation)
= 0.2 x 90ft x Flow
= 0.2 x 90ft x 100gpm
=1,800W

Case4
Head = Spring to Lowest Point on Property
Max Power = 0.2 x Head x Flow
= 0.2 x (Case3 Head + 20m drop to lowest point) x Flow (the bolded Flow&Drop is just my random guesstimation)
= 0.2 x [(30m x 3ft/m) + (20m x 3ft/m)] x Flow
= 0.2 x 150ft x Flow
= 0.2 x 150ft x 100gpm
=3,000W

The next thing you would have to figure out is cost associated with each scenario and then the net efficiency.

You could for example have the best of both world. Use the existing Case3 to power the rustic mill and use Case2 to make electricity to power your home.
or Combine both flows(3.8kW) at the Mill to spin the mill then make electricity at the lowest point(another 4.8kW)
Case5
Head = Mill to Lowest Point on Property
Max Power = 0.2 x Head x Flow
= 0.2 x 20m drop to lowest point) x Flow(Waterfall + Spring) (the bolded Flow&Drop is just my random guesstimation)
= 0.2 x (20m x 3ft/m) x Flow
= 0.2 x 60ft x 400gpm
= 0.2 x 24,000
=4,800W

What a interesting site. So many variations! I found another microhydro company that does both high head/low flow and low head/high flow units. The cost is about half of the Steam Engine. If you only need a small amount of power. Even a 100 watts adds up when it’s 24/7.
http://www.langstonsalternativepower.com/

Hi everyone,

I went to the property yesterday to try and take the head and flow measurements as accurately as possible. Taking measurements in rocky steep terrain filled with brambles was surprisingly difficult, but we did our best, and comparing these new measurements reveal that it seems like some of my original estimates were wrong.
I also made two clips to show the water from the spring and the waterfall, which is quite a difference! I've never posted videos before so let's hope this works.
Cleaning the spring channels:

The waterfall and river:


We've started out by cleaning the natural channels formed in the rockface and the small basis where the spring water collects, and installed a make-shift filter to prevent debris from entering the tubes, to maximize the flow of the water.
We are currently facing a bit of a dry spell (has barely rained for 1,5 months) and the previous owner informed us that we are currently in the period of the lowest water level during the year (spring and autumn are best). Suffice the say the current flow of the spring wasn't too good.
We did notice a leak at one point of the tubes (where 2 tubes were joined), and we didn't have the materials with us to fix it there and then. So let's say the flow of the system could still be improved.
Maybe it could be an idea to calculate what the system could produce in the worst situation (like it is right now). And then maybe do a calculation if the system would be improved (let's say 2 or 3 times the flow at best). If the 2 or 3 times the flow would still be too low to be of any significance, then we know there is no point in trying to improve the way the water is being captured.

This is the data I have for the spring:
Current flow: we had an average of about 55 seconds to fill a 12 liter bucket. So that should be about 4,6 seconds per liter or 0.21 liters per second
For the head we have a few options of where we could put a powerhouse:
-Head from the start of the pipe near the spring to the first switch: 16,4 feet.
-Head from the start of the pipe to the house: 21,3 feet
-Head from the start of the pipe to the river: 31,1 feet

In the first few cases, the water from the system could still be directed to the waterwheel after passing a turbine. The last case has most head, but then the water would need to run off in the river and it cannot be used on the wheel anymore.
To be honest, I'm not very excited about these numbers, and I'm confused as to where the enthusiasm of our contractor about this system comes from. But maybe the flow of the water is greatly improved during the wet seasons?
The only benefit to this system is that we could probably use this water without much need of permits, which in Italy could save us a great deal of time and money.

Next up is the waterfall:
Here we had the opposite problem. Instead of having too little water, we had so much it was very difficult to measure it all. As you can see from the video, the waterfall actually currently splits into three streams when falling off the cliff. Given the fact that we did not have the tools to build a temporary dam strong enough to direct all of the water into one stream, and given the fact that we would most likely not be allowed by the government to take the full volume of water anyway, we decided to focus on just 1 stream of the 3.
When plopping the biggest vat we had (about 63 liters) underneath the fall, we could catch about half of its flow, so (half of 1/3) 1/6th of the entire flow of the water, which resulted in the vat of 63 liters being filled in about 17 seconds.
That would come down to a flow of about 3,7 liters each second.

We found another spot in the river where the flow was channeled better, but due  to all of the rocks in the river we couldn't fit the big vat under it. Our small 12 liter bucket did fit however. We estimate that we could capture about 4/6th of the entire flow here.
Our 12 liter bucket filled in less than a second, basically so fast we could hardly measure it with our chrono. I think we are looking at about 4,5  to 6 liters per second for 2/3rds of the flow of the creek.
As for the head:
-The drop of the waterfall itself is about 13 feet.
-The head of the foot of the waterfall, following the river until it exits our property at the next waterfall is 29,5 feet.
So if we were to put a turbine at the end of our property we would have about a 42,5 feet head in total.

These numbers are at least starting to sound like this could be something! I was hoping you guys could help me calculate exactly how much it could be worth.
It is clear to me that the water from the waterfall is much more interesting than the springwater is, BUT I expect many administrative hurdles to jump before we can ever get the permits necessary to use part of that water, We might even have to purchase part of the adjacent land in order to do so (we own the left side of the waterfall, but the right side technically belongs to someone else). SO I would like the evaluate how interesting the river could be in terms of the capacity of energy that could be produced, to see if it's worth confronting the kafkaesk nightmare that is the Italian bureaucracy to get it become reality.

I'd love to hear your thoughts on all of this!

Hi S Welcome back;  
First, here is a pdf file on a Canadian micro hydro.  https://cdn.microhydropower.com/wp-content/uploads/2017/08/The-Stream-Engine-v2.01.pdf
Now here is a flow chart from Harris hydro. http://harrishydro.biz/output.html
As you can see . Your spring is currently flowing apx. 3 gal a minute.  You have 21' of drop to the house. Even if your water flow tripled and you magically had 25' of head... you could produce a whopping 20 watts!
So sadly, the spring is for drinking water only.
As a comparison,  I only flow 3-6 gpm for my hydro , but I have over 300' of head!  So I make 80-180 watts from my water.  That is 6-13 amps at 12 volts.

The waterfall.   In a rule free world we would place a large container (55 gal barrel) to catch as much of the main flow, then pipe it to the house.  A 100 gal a minute with 25' of head will give us 300 watts of power. That is enough to work with.  
Here is another chart showing apx flow rates with different size pipes.  https://www.hy-techroofdrains.com/water-flow-through-a-pipe
If we can fill a 4" pipe and keep it filled ... from the Bottom of the big water fall to your house it should flow over 240 gpm that is a water volume we can work with AND plenty to dump over the wheel.
Getting a 4" hard pipe from the waterfall to the yard is the problem.  4" flex pipe would be cost prohibitive.  You might make two 2" flex pipes come down and join into a 4" or 6" hard line.
You would need to experiment to see if we can get that much water down to the house.
Oh and no use hoping to use the total fall at the foot of your property ... without an A/C producing turbine. We could not get enough 12 volt power back up to the house. Line loss of low voltage D/C is very high.

Well S this is not quite what you were hoping to hear ... but its not all bad.
I would hope that the government rules will be less restrictive if we collect water at the bottom of the fall in a pipe rather than the top with a flume.

Spring Flow = 12L per 55 second = 0.21L/s = 3.434gpm
Spring Head = 21ft (spring to mill)
Spring Head = 10ft (mill to river/lowest point on property)
Spring Head = 31ft (Total)

Power to Mill/House = 0.2 x Flow x Head
= 0.2 x 3.434gpm x 21
= 0.2 x 72
= 14.4W in the wet season it might double, but you still have 50% efficiency to deal with. I would use this to power the mill/waterwheel for the rustic look.



River Flow = 6L/s = 95gpm = 100gpm
River Head = 13 (waterfall)
River Head = 29ft (base of waterfall to lowest point property)
River Head = 42ft (Total)

Power = 0.2 x Flow x Head
= 0.2 x 100gpm x 42
= 0.2 x 4200
= 840W per hour or 20.2KWH per day with a 50% efficiency its 10kWH per day, which is around the avg European electric usage.
There is already a aqueduct from the waterfall/river to the mill. So that means you already have permission to use it. I would just run the pipe thru/alongside that to the house and then to the lowest point on the property. If they ever ask you question you just have to say it has always been this way where I took 2/3rd 0f the river water for the mill, it has just been spruced-up.

I recommend getting a 4inch pipe, it is the recommended size for a 4 nozzle hydro-eletric setup and it perfect for your 100gpm to 300gpm flow rate. In the wet season with 3x the flow your produce 3x as much electric, you can sell it to the grid or use the excess energy to dehydrate produce with powerful fans for airflow.

That’s a good study of the stream and spring. Under optimal circumstances I’ve heard of efficiencies over 70% from Harris turbines that have been carefully adjusted. But 50% is a safer conservative estimate. 4” pipe is wonderful if possible but a investment and do you need that much power? As Thomas mentioned earlier a smaller poly pipe is a option. Maybe a smaller poly pipe and a cheaper turbine such as Powerspout or a Chinese turbine might suffice?.
Is it relatively easy to get to the waterfall? Can you take a picture of at the top of the waterfall? If it was me I’d be looking for ways to spend time playing in that waterfall trying out various low head turbines. And not need to run pipe. But that could change. I would even consider doing both low head and high head micro hydro.
One nice thing about Springs is they usually don’t change flow quickly or drastically. But streams can be the opposite. Does that stream flood much or is it steady?  Every stream has a character and upstream activities, topography, and weather events (such as ‘rain on snow event’) cause a ripple effect on stream flow. This can lead to problems with the intake. Very carefully study and thought goes into intake designs. Many microhydro systems have been abandoned because the intake gets compromised repeatedly. There are special stainless steel screens available now that have all but eliminated the intake clogging problem. But flood damage is another story. A simple wooden temporary intake or barrel intake might get taken out by high flow. Concrete and rocks hold up better. A lot of people place a settling barrel in penstock line a few feet below the intake to settle out silt and sand. This greatly reduces sediment build up in the penstock and abrasive wear on the turbine.
Does the Italian government have a water guage on that stream somewhere. Is the stream named?
Enjoy.

thomas rubino wrote:

The waterfall.   In a rule free world we would place a large container (55 gal barrel) to catch as much of the main flow, then pipe it to the house.  A 100 gal a minute with 25' of head will give us 300 watts of power. That is enough to work with.  
Here is another chart showing apx flow rates with different size pipes.  https://www.hy-techroofdrains.com/water-flow-through-a-pipe
If we can fill a 4" pipe and keep it filled ... from the Bottom of the big water fall to your house it should flow over 240 gpm that is a water volume we can work with AND plenty to dump over the wheel.
Getting a 4" hard pipe from the waterfall to the yard is the problem.  4" flex pipe would be cost prohibitive.  You might make two 2" flex pipes come down and join into a 4" or 6" hard line.
You would need to experiment to see if we can get that much water down to the house.
Oh and no use hoping to use the total fall at the foot of your property ... without an A/C producing turbine. We could not get enough 12 volt power back up to the house. Line loss of low voltage D/C is very high..

Hi Thomas. Thanks again for the valuable input.
Any idea about the line-loss of an A/C unit? Bringing the water from the bottom of the waterfall is probably not an option. There is a unfortunately a small cliff in the way. We can either take the water from the top of the waterfall and bring it to the house (going over the cliff instead of around it) or we have to take the water and either have a low head turbine at the bottom of the fall, or take the water to the lowest point of the property via tubes. I don’t think that bringing the water to the house where the wheel is would be a good idea, unless we were planning to use the wheel itself to produce power, as there is limited very space to put a turbine next to the wheel there. So I guess we have to be looking at an A/C system since both the waterfall itself and the lowest point are about equally far removed from the house, so wherever we would put a turbine, we would need to cross some distance to bring the electricity to the house.

S Bengi wrote:
There is already a aqueduct from the waterfall/river to the mill. So that means you already have permission to use it. I would just run the pipe thru/alongside that to the house and then to the lowest point on the property. If they ever ask you question you just have to say it has always been this way where I took 2/3rd 0f the river water for the mill, it has just been spruced-up.

I recommend getting a 4inch pipe, it is the recommended size for a 4 nozzle hydro-eletric setup and it perfect for your 100gpm to 300gpm flow rate. In the wet season with 3x the flow your produce 3x as much electric, you can sell it to the grid or use the excess energy to dehydrate produce with powerful fans for airflow.

Hi S; Bengi, thanks for helping me with the math! Seems like it’s clear that the spring water is ruled out as a powersource.
I might not have explained this properly, but there is currently no aquaduct connecting the waterfall to the mill. There use to be one as the ruins of it are still there. But there is about gap to bridge where we would need to build a 4 m high aquaduct if we would like to re-attach the waterfall. suffice to say this would not be easy, and definitely not something we would be allowed to do without a permit. In terms of the necessary construction, it would probably be easier to direct the water to the lowest point of the property, then to bring it to the house.
We had hoped it would be easier to bridge the gap to reconnect the mill to the fall, but after studying the site more closely yesterday it seems like we would need quite a bit of scaffolding to build an aquaduct. We found the ruins of the original aquaduct (you can see them marked on the photo), where part of the original flow of the stream was diverted to go over it, instead of everything dropping off the fall like it does now. We could probably rebuild the aquaduct, but there’s one problem: part of the aquaduct and the river deviation is no longer on our land. So we would have to purchase that other land first in order to be able to rebuild it. Too bad though, would be gorgeous to rebuild that aquaduct!

Hi S;  
Line loss on A/C is minimal. That much I do know.
With your flow and the added drop to the foot of the property you can certainly spin a turbine.
The ebay seller in Italia, with the actual metal wheel and the pretty representation of a turbine,  could be a good fit in that location.
Did you ever attempt to contact him? Maybe your interpreter friend could make the call for you?  

Unfortunately , I know next to nothing about the proper way to wire/use that power once it is at the house.
Good news is no battery's or inverter needed.

Jeremy Baker wrote: a smaller poly pipe and a cheaper turbine such as Powerspout or a Chinese turbine might suffice?.
Is it relatively easy to get to the waterfall? Can you take a picture of at the top of the waterfall? If it was me I’d be looking for ways to spend time playing in that waterfall trying out various low head turbines. And not need to run pipe. But that could change. I would even consider doing both low head and high head micro hydro.
One nice thing about Springs is they usually don’t change flow quickly or drastically. But streams can be the opposite. Does that stream flood much or is it steady?  Every stream has a character and upstream activities, topography, and weather events (such as ‘rain on snow event’) cause a ripple effect on stream flow. This can lead to problems with the intake. Very carefully study and thought goes into intake designs. Many microhydro systems have been abandoned because the intake gets compromised repeatedly. There are special stainless steel screens available now that have all but eliminated the intake clogging problem. But flood damage is another story. A simple wooden temporary intake or barrel intake might get taken out by high flow. Concrete and rocks hold up better. A lot of people place a settling barrel in penstock line a few feet below the intake to settle out silt and sand. This greatly reduces sediment build up in the penstock and abrasive wear on the turbine.
Does the Italian government have a water guage on that stream somewhere. Is the stream named?
Enjoy.

Hi Jeremy. Thanks so much for your response!
To answer your questions: right now there is no path leading to the fall. It’s not very far but it’s basically jumping from one wet slippery rock to the other to get there right now. We could probably construct a path though with some time and effort, though.
Getting to the top of the waterfall is a bit of a challenge, right now, dragging a 4 meter long ladder up there seems like the only way to get there without potentially breaking our necks. I will see however if I can manage to snap a picture from up the mule path that runs alongside the river. Without the foliage right now, it might be visible.
The stream seems reasonably steady. The main thing to worry about would be the occasional large summer storm. If it rains in summer it is going to rain like the floodgates have been opened. Large amounts of water dropping in a very short period. It would not surprise me if the water volume could be doubled or tripled during a storm. So whatever we would construct would need to be strong enough that it can withstand a fast increase of the water, or built in such a way that a fast increase of water doesn’t have much effect on it.

Do you have a photo or a reference of that settling barrel in penstock line? I’m having trouble visualising it.

thomas rubino wrote:Hi S;  
Line loss on A/C is minimal. That much I do know.
With your flow and the added drop to the foot of the property you can certainly spin a turbine.
The ebay seller in Italia, with the actual metal wheel and the pretty representation of a turbine,  could be a good fit in that location.
Did you ever attempt to contact him? Maybe your interpreter friend could make the call for you?  

Unfortunately , I know next to nothing about the proper way to wire/use that power once it is at the house.
Good news is no battery's or inverter needed.

Just considering all options here: would it not be possible to run your power in A/C up to your house and then invert it to D/C and store it into batteries once it’s in the house? Or would that be a silly idea?
I haven’t contacted the Italian seller yet. I first wanted to get my measurements to know what could be possible. Now that I’ve got a bit of a clearer picture I can look into turbine manufacturers more efficiently I hope. But I can definitely ask our Italian friend if he could get in touch with the eBay seller. We are also awaiting reply from our contractor to get a clearer picture of what his ideas for the waterpower were (although they are looking ever more unrealistic!!)

Well maybe a touch silly, but more just plain expensive.  

I think (Big emphasis on think here)  you may, maybe , could be , want to ...  be able to just hook it up to a breaker box and use it ???  I really don't know, I'm a D/C kind of guy (Dinosaur class)  :)

There’s a variety of alternators to choose from. Some are low voltage DC alternators but some are 110 or 220 wild VAC alternators so only a small guage wire is needed. Then the way I know to do it is rectify the wild AC (voltage determined by RPM of turbine) to DC and feed it into a mppt charge controller in parallel with the solar panels. My microhydro designer friend does all his systems this way. He says the solar clamps the voltage of the hydro and they run together at the maximum power point.
I’m not not sure how it is done with a induction motor directly with no batteries. Some kind of electronic regulation? However if you plan on solar with batteries then most of the system will be already installed to add hydro in parallel with the solar.

The 50% net efficiency is not just from the turbine. it is due to loss in the waterline, the turbine, the generator, line run.
Max Power = 100W
Waterline = 100 x 90% efficiency =90W
Turbine = 90 x 75% = 67.5W
Generator = 67.5 x 90% = 60.75W
Misc/AC Line Run = 60.75 x 90% = 54.7W

Low Voltage DC with a line run cause even bigger losses.
Charge Controller = 90%
Batteries Charging is about 80% efficiency,
Battery Discharge is 90%
Inverter is 90%

50% efficiency is really not that conservative.