Help with Micro Hydro

[TheCasualTraveler]

     Having just returned from our place in the North Carolina mountains I am ready to get started on the project that brought me to Otherpower in the first place. For reference, I'm thinking along the lines of the Otherpower project shown here,

http://www.otherpower.com/scotthydro1.html

Here is a short video of the creek I will be working with,

http://s241.photobucket.com/albums/ff74/compoast/?action=view&current=Waterfall.flv

     The water flow is not great but the speed is quite good as the whole slope of the mountain is something like 30% or better. The creek must be spring fed because this area of the Southeast US has been in a drought for sometime. So the flow in the video is on the low side and runs like this or better all year. I would like to do this with as little disturbance to the creek as possible and want to build a small squirrel cage type wheel to suspend in the water at the small falls. Maybe a steel post set in the rock at the bank of the creek with an iron rod like a gate that swings out. 1 or 2 amps at 12 volts 24 hours a day would be just fine with me. I prefer not to do any damming or diverting because my property line is in the center of the creek and I want to stay on good terms with the neighbors should they ever develop their side of the creek.

     So, the questions,

     Should I build the wheel to the dimensions in the Otherpower link ( the fins being 1/4 of a 4" pipe)and the diameter being 12" or can I improve? (Scott are you reading this?)

     And second, building the above design I would like to use PVC pipe for the fins, plate aluminum for the sides, held together with all thread and to keep the PVC in place cast the ends like a magnet rotor. Sound feasible? or,

     Is there something out there, easy to obtain that will save me the trouble?

Thanks for reading,

Andy

     

[scottsAI]

TheCasualTraveler,

PVC plastic comes in sheets, glue fins in place much easier!

Make sure the feed pipe area is several times larger than the nozzle.

Have fun,

Scott.

[TheCasualTraveler]

     PVC in sheets? No way! Really? Where would I look for it? I've got to have some.

Andy

[ghurd]

I can't tell how far the waterfall falls.

Wondering: Maybe run a 2" or 3" PVC pipe 30' up the hill, 1/2" or 3/4" fitting on the end, then a little Pelton wheel...

Maybe a 90V DC motor and a home brew Pelton wheel of soup spoons?

More pressure, less water, more RPMs?

Not a joke.  I would love to try it!  Might not work, but it would be fun.

No water like that around here.

G-

[TheCasualTraveler]

     Thanks Ghurd, that may be something for the future but for now I want a very non-invasive setup with the only diverter being possibly a scoop attached to the wheel assembly and not touching the creek bed, just in front of the wheel to channel the water.

[scottsAI]

Andy,

PVC plastic is Polyvinyl Chloride:

http://en.wikipedia.org/wiki/Polyvinyl_chloride

Sheets:

http://www.usplastic.com/catalog/product.asp?catalog%5Fname=USPlastic&category%5Fname=115&pr
oduct%5Fid=10041

Not exactly cheap, look around this was my first hit on it.

Heck of a lot easier to build it with PVC ends.

If much sand in water the plastic may wear faster than metal.

I have studied the Banki turbine, interested in helping design one.

Have fun,

Scott.

[TheCasualTraveler]

Thanks Scott,

     I was hoping I would hear back from you. Am I right in thinking you are the Scott with the waterwheel in the Otherpower link I posted? If so, is your wheel still running? I'd be interested in any more data or changes to the design (of the wheel , not the alt)since the webpage was put up.

     I priced online PVC also and it adds up with shipping. I thought of another design, to glue 12" pvc paddles onto a piece of pvc pipe 6" od by 12" long and then cap both ends off. In the Otherpower writeup it said the water went into the wheel around 10 o'clock and exited around 5 o'clock (dern that's a long time for the water to be in there) Just kidding. But anyway the way I mention above the water would just be held in a bucket and then dumped. I wonder how the efficiency differs between the two and if it really matters on such a small wheel.

[scottsAI]

Andy,

Sorry to disappoint, Not the Scott with Banki on otherpower web pages.

But I can answer your question.

"glue 12" pvc paddles onto a piece of pvc pipe 6" od by 12" long and then cap both ends off."

This would be very bad, the banki is a Impulse turbine, the water needs to hit blades at kenitic speed and bounce off, it must go some where. Water wheel works differently.

Banki turbine Nozzle converts the pressure into velocity...

And, Efficiency would suffer, Banki is 80% efficiency the second pass is important supplies 1/3 of the power.

The Banki works efficiently with low heads AND easy to make.

http://en.wikipedia.org/wiki/Banki_turbine

http://en.wikipedia.org/wiki/Water_turbine

Large modern water turbines operate at mechanical efficiencies greater than 90%. (Pelton)

My study of small Pelton reveled they rarely achieve much above 80%, partial load much less 80%, making the Banki the winer for micro hydro. Try building a Pelton!

Have fun,

Scott.

[scoraigwind]

You really are missing out big time by not using a pipe to build up a head of pressure. You could divert only a small portion of the flow into a pipe and using it to get a decent head and produce a lot more power with a lot less impact on the stream than you will by using just the kinetic energy of a small water fall.  

[TheCasualTraveler]

""You really are missing out big time by not using a pipe to build up a head of pressure. ""

     Of course your right. I guess what I'm after is just a little hands on experience. A small test wheel to get a feel for what power is in the water. My estimate is that I have about 20 to 30 feet of head from the top of my 1 1/2 acre lot to the bottom. To make the most of this I would have to divert water from the top corner of my lot right where there just happens to be a very scenic waterfall (upstream from the one in the video). The creek bed is solid smooth rock, no sand, no stones to hide a pipe and if I was in my neighbors shoes I would not want to see a pipe in that area.

     If I do divert to a pipe I suppose the best turbine would be a pelton (high head/ low flow)

     Of the types of wheels recommended I wonder what would be best if you discount head (indirectly since the pressure would not be built up in a pipe) and instead figure for a very fast moving small stream. Guessing, I would say the stream is between 60 to 70 gallons per Minute (or 1+ gallon per second) But it slides down fairly smooth rock at an angle that gives it a lot of speed. I think I might do ok with a cross flow type wheel setup at a natural ledge with a natural looking funnel of rocks of logs squeezing the flow into an area about 1 foot wide. Looking down the creek / falls from upstream the wheel could be completely hidden behind a ledge.

     At this time, our lot is undeveloped save for the septic drain field. I have the opportunity to design our cabin to be off or nearly off grid if I combine hydro with solar and conservation. I suppose under 100 watts can go a long way when it is 24/7 and combined with solar.

     We'll be up there again next month and I plan to build a small test cross flow wheel, quick and not too fancy just plywood and PVC.

     Oh, I almost forgot. Another question,

In researching the forum I saw where Flux wrote to another poster;

""I assume you have looked at matching the alternator to the wheel, if you have too little open circuit volts or too much resistance you may not be fully loading the wheel. Have you checked the power direct into lamps, which you can keep adding until you slow the wheel to where water spills over the buckets.""

     I'm curious to know more about alternator cut in when attached to a water wheel charging batteries. Seems like a whole different set of rules from wind turbines. Would things like tip speed ratio and stall apply? Or are the only 2 parameters - the ability for the wheel to startup and when the water flow exceeds what can be used? If the latter then can the coils be would with a high number of turns for low rpm charging or would this be a disadvantage same as too low a cut in on a wind turbine?

Help comments and criticism appreciated,

[dnix71]

There is a fellow in Guatamala that has made a 5 gallon bucket pico hydro unit.

His unit looks about the right size for your stream.

http://blog.makezine.com/archive/2008/06/bucketborne_hydroelectric.html#comments

He used 135 degree pcv couplings for vanes.

[spinningmagnets]

This is a great find, dnix71!

Here's some more pics of the 5-gallon bucket "Pico-Hydro":

http://www.flickr.com/photos/aidg/page5/

The generator "appears" to be a car alternator that is converted to a PMA. By using it to charge cell-phones, I'm guessing "it must" be making over 9-volts.

As I understand it, cell-phones, laptop computers, radios with re-chargeable 9V batteries, and LED flashlights with rechargeables, are common in this voltage range so they can re-charged by a 12-volt car system (among other charging sources, of course).

[DanG]

Your video reminds me of Ozark porous rock-ridge hills where if you get a good cloudburst small rock ledges sprout fire hydrant plumes for an hour and go dry again, without much disturbance to ground leaf cover and small plants & saplings downstream. You or yours are extremely smart to have latched onto the property with a drought-proof stream!!

I'm not ragging on you here (much) but you saying 'it must be spring fed' makes me think this may be a guerrilla install on someone elses' stream, why else would you not have walked it and defined the source?

Have you seen your rivulet after a gully-buster cloud burst or after a tropical depression takes a week to pass over? The scoured area beside the center channel and the cratered pool beneath makes me think a tremendous amount of water blasts through there regularly.

A small impound pool at top and parallel pipe run to a brick power house with the tail water returning to the channel would increase survivability if/when branches, small boulders and leaf snags plow down in storm runoff like small bulldozers...

[TheCasualTraveler]

     Thanks Dnix, I always like when common, easy to obtain materials can be incorporated into a sophisticated design.

[TheCasualTraveler]

I assure you DanG this is not a "guerrilla install on someone elses' stream"

     I know that just up the mountain there are several springs that feed this creek and my comment was only to say that not knowing all the source of the stream I suppose the regular steady flow is due to being spring fed.

     After Hurricane Frances some years back it looked like someone had widened the stream bed with a pressure washer. I always describe our mountain stream by saying, imagine Stone Mountain in Georgia, that big rounded boulder of a mountain. Now cover it with 3 feet of dirt, add trees and cut a 10' path down to bare rock for a stream and thats pretty much it.

[Stand]

Hi G...Exactly what I was thinking in terms of a Pelton wheel. All you really need for a Pelton wheel is a lot of altitude,AKA a high pressure source. Most small creeks will satisfy the flow needs, and the reservior can be as simple as a 5-gallon bucket about 100 feet or so above the Pelton wheel, so let your imagination be your guide. Maybe a small pond at the upper end to soak up the variance in rainfall?. If you had a large pond, it could store lots of power in the form of kinetic energy that has not been used yet. Pelton wheels can possibly turn up past 10,000 RPM, if they are correctly engineered, so please be careful, whatever you do. The supply pipe could be as small as say 3/4's of an inch, very economically acheived by using 500 foot? rolls of black polyethylene tubing/pipe. Be aware that at 100+ feet, the back pressure will be at about 3 Barres, or about 45 PSI, so it will hurt if it squirts you in the eye.

Cheers,

Stan E. Delo

Port Townsend, WA

 

[Stand]

Sorry to post twice, but the idea mentioned herein reminds me of a waterwheel patent I saw from the 60's or so, wherein the horizantal shaft waterwheel looked somewhat like a reel type of lawn mower with the spiral portions filled in with material. If the horizontal axis of the reel could be adjusted, it might be able to toss unused water back, or otherwise do something reasonably smart with the unused water. In fact, you could use crossflow to augment the torque of a spiral type of wheel, at a very low cost expended in terms of kinetic energy. (Only about 5 feet of head to spin it)

Hasta la vista,

Stan~  

[ascii122]

thats pretty cool.

I made one out of a 55 gal olive barrel, but the same basic idea.

http://www.homebrewhydro.com/

This one uses a standard pelton wheel and PMA