High speed or Low--AC or DC

[Harold in CR]

Have someone in the community wanting to put in an off grid hydro system. Went to look at his site and HOLY MOLEY.

 He has a 14" ID steel pipe shooting a FULL stream of water about 6 feet out before it starts to turn down into the washout below. He says rain does not affect the flow rate, noticably. It is a branch off from the river where the inlet is submerged about 2 feet below the surface in a 6' deep cut in the river on an outside bend. This is right before a waterfall, so a pooling effect.

 It's approximately 30' of head to a concrete walled area where a "Pelton" once lived. Needless to say, I'm overwhelmed with how to advise him. He doesn't know what he has or needs, just "wants to run a house on the farm". 

 For starters, I did measure his chaseway capacity. It runs water 19" wide X 16" deep. Knowing I need many more measurements, I will return to the site one day this week.

 Meanwhile, Is a high RPM turbine system beneficial or a low RPM turbine system more practical ? Looking to keep maintenance to a minimum and longevity to the maximum. Also, which might be a better system, a DC system with inverter or a direct AC system with a small battery for backup ? On a quick trip through Ebay, I found a NEW 1800 RPM 2.5 KW alternator that would be belt driven. I have no idea if this would be a usable item or not. Also, need advice on whether a Pelton or a Banki turbine is better and how to size it.

 Once I gather sufficient information, I will start a build thread, if I get to work with him on this. In the interim, any suggestions would be greatly appreciated.  Thanks

[mab]

For a start i'd put the figures into powerspouts calculator - 14" penstock, 30' head, approx length of pipe - just put a big number in for gallons/min and it'll tell you how much will fit down the pipe. It should tell you how much power is available.

That's fairly low head for a pelton or turgo, so both will run at low rpm (don't know about banki - not sure what it is), so you may end up gearing it up anyway.

I guess you might find it difficult to find an off the shelf single pelton / turgo that can take so much water. So I'd look for available turbines at that size/capacity and see what generators they come with (if any) or what speed they turn with your water source.

[keithturtle]

30' is only meaningful if it stays in the pipe all the way to the turbine.  If it can be contained, I think a Leffels type reaction turbine https://en.wikipedia.org/wiki/Water_turbine
would be most suited for that head and flow, from what I've read.  With that much resource he might could power more than just his own place with the right setup

The Banki would work too but wouldn't be as efficient; it is used to maximize for variable flows

Turtle

[Harold in CR]

Thanks for the input so far, guys. That Leffels looks like a bear to build and shipping would be astronomical.

 Keith, look up the Ossberger design. They claim up to 86% efficiency. They also incorporate a vacuum pulling the water into the turbine.

I think a 5 KW unit will be more than enough because housing here is no where near comparible to US housing. My electric bill says we use 300 Kwh more or less per month. I do use welders, power tools and charge power tool batteries, but, I believe I have a section of the power line has leakage due to corrosion. I will replace that soon.

Refrigerator, clothes washer, NO dryer, possible electric stove, but, propane is normal here, but  expensive, and lighting, is about all they will have.

 Won't have measurements until next week. Can't do it alone and he is busy cleaning out our water system here this week. We have gravity fed community water and has several concrete "tanks" along the way, above ground, that need cleaning of sand, etc. and bleaching  right before our dry season, which starts within 5-6 weeks for 3 months or so. Even then, he says his water supply on the farm never varies noticably. Wish I had that much crossing my place.

[SparWeb]

Your friend might have about 50 kW of potential on his hands.
You could consider the business value of this resource.
50 kW * 24 hours = 1200 kWhr
@ 10 cents/kWhr this earns 120$ per day
These calculations may be completely inapplicable to your location, so I'm just showing the economic favour for this - if it were my dam.  YMMV

[Harold in CR]

Sparweb, I fully agree with you, however, down here, people only think of themselves. They pay the equivalent of 25 cents/Kwh and the neighbors all do the same.

 It's similar to EV's, the price is too high to go fossil fuel free, but, still pay the nearly $1.00 /litre for gasoline and Diesel.

 Still waiting for the guy to call so we can go back to get accurate measurements and photos.

 Meanwhile I have to get my tower built. 

[SparWeb]

Sure.  Priorities.

More silly questions
When you tell someone they can get 50,000 USD per year from a stream on their farm, is it unrealistic to expect them to get excited?
Would they be willing to sign a 99-year lease to you instead?

[Harold in CR]

You got it right, silly questions. 

First problem is, years ago farms had "Peltons" whatever that referred to. They channeled water from rivers to run them. I believe they had undershot or overshot wheels. Any form of turbine is a Pelton.

 Second, lack of people close enough to supply electricity, and third, will not pay for lines to connect, and more probably, Govt. doesn't like competition. ICE, forget what the stands for, is the only producer of electricity, and a couple of large companies buy from them to sell to outlying farms.

I had one ask me to investigate his water that ran 50/GPM in the dry season at 300' head. I told him furnish the material and I would build the system at his remote farm. 3 years later, after asking him several times about material, he had one of the buyer-seller companies run 2 miles of wire and hooked him up free, and a cheaper rate. 2 years later I asked him how the rates were and he said EXPENSIVE. 

I'm nearly too old to really care anymore. The old saying, you can teach someone, but not very much, rings true here. 

[SparWeb]

[insert snarky comment here]

Well, I don't really understand the lack of concern or industriousness, but then again, I am often reminded (by the daily news) that I really don't understand my own culture, either. 

[Harold in CR]

I used to make small talk with the kids at the bus stop. Things like what are their interests, what would they like to learn as a trade or job after graduating, and 99% of them had no idea or were satisfied cutting their farm areas with weed whackers, yes, acres and acres, besides milking cows.

I'm self taught in many things, maybe not professionally qualified, but, was willing to teach them some kind of trade I was good at, and there are many.  Most don't believe their is a life outside of this area, have never been to a big city, like San Jose, and have very little if not absolutely unsure of locations of any other country around the world. They all talk about going to Miami, meaning the USA. I try to explain the difference, but, not interest in learning.

 However, they can all manipulate their cell phones as good as Space Shuttle pilots.    It's sad, really. Biggest part of the population works for under $4.00/hour. 

[keithturtle]

It's sad, really. Biggest part of the population works for under $4.00/hour. 

Wow.  I guess you cannot teach motivation when mediocrity is all they've ever known

Turtle