Run of River Microhydro

[flintcreek]

Nando,

   Here's most of the info you required:

The width of the creek, at what I think is the best spot to site the turbine, is 36 feet. This is one of the creek's narrowest spots on my property. I measured the depth at 1 ft. increments across that spot and got a minimum depth of 4 in. and a maximum of 16 in.

   I also measured the drop for 600 ft. The results were not encouraging! I overestimated the drop considerably. For the first 100 ft. leading to the proposed site the drop was 9in.. The next 100 ft. had a drop of 5 in. I only continued measuring for another 400 ft, and the drop was consistent at 4 in. per 100 ft.

   I also measured the water's velocity at the site. It was only 3.8 fps avg. for four measurements.

   One thing about these measurements: Theses were taken after an unusually dry spring. The creek depth is unusually low. Also, I'm not much interested in making a lot of power in the warmer weather. If I get it , fine, but my main use for the power will be water heating during the winter. I would conservatively estimate the creek level to be almost double what it was in these tests. I've taken velocity readings in the fall and gotten 8.6 fps.

   To answer a few of your other questions:

1. The length of the creek though my property is about 2200 ft. (as the crow flies).
   
2. How the creek enters my property- I didn't understand the question. could you re-phrase it please?
   
3.  The type of fish. I don't know what they are, but they are nothing rare. Just minnows and what the locals call "creek chubs" the longest fish I've seen is about 4" long, at most.
   
4. How much power am I hoping for? I'd like to see 1000w to 1500W. I guess anything over 500w is probably worth pursuing. Less than that probably makes it uneconomical.
   
   

   I tried taking photos, but had a problem with the memory card.  I'll re-take them and include a map of my property in a few days.  Thanks again!

[flintcreek]

OOOPS! I forgot the most important part of the data: The average depth of the creek at the proposed site was 7.7 in. Kinda need to know that! Would it help to post the individual readings at 1 ft. increments?

[Ungrounded Lightning Rod]

Ok, let's do some ballpark numbers:

3.8 ft/sec, but that's at the surface.  Let's cut it just short of in half for friction with the bottom and sides.  (I'm not sure how to derate this properly so I'm winging it.)

 - 2 ft/sec *

 - 36 ft width *

 - 7.7/12 ft average depth *

 - 7.48 gal/cu ft *

 - 60 sec/min =

20,735 gal/min

Let's assume you can divert half the flow through a raceway or something and get all but a foot and a third of the head on your land to appear across your turbine.  We'll take your 4"/100" and the crow-flies distance from in to out:

 - 4/12 ft/100 ft run *

 - 2200/100 ft run =

 - 7 1/3 ft head -

 - 1 1/3 ft head lost =

6 ft of head

Now for horsepower:

 - 10,000 gal/min *

 - 8.33 lb/gal *

 - 6 ft head /

 - 33,000 ft lb / minute /hp =

 - 15.45 hp (in the water) *

 - 0.6 (assumed turbine/generator efficiency) =

 - 9 hp *

 - .746 kw/hp =

6.78 kw.

Well, that's encouraging.  You wanted about 1.5 kw in a high-flow winter and you've got about 4 1/2 times that during a low-flow spring.  That's a comfy margin to make up for errors in the above assumptions.  Maybe you don't need the fancy head-preserving raceway or plumbing and half the river's water.

[Nando]

SEE why I asked for such measurements = It is the most common error done by most, to miss calculate heights and water velocities and as well water volume

It seems as well, that the stream at minimum level, like know, is producing around 1 cubic meter/sec

The initial measurements indicate that you have around 4 inches per 100 feet, water velocity seems to indicate that is the slope of the stream.

If you take 54 inches (1200 feet stream length) for 48 inches head and about 200 liter/sec, then

48 inches = 4 feet = 1.2 meters

Power availale (watts) = 1.2 * 200 * 6 = 1440 watts

How: 1200 feet = 366 meter of 12 inch= 300 mm sewer pipe USING AN IN-LINE propeller and a small DAM up stream for winter increasing the head by 1 or more feet ( each additional 1 foot= 300 mm head the power increases by 360 watts with the same water volume, but the water volume may increase ( if allowed) for maybe another 50 or so watts.

If a 14 inch = 350 mm and allowing around 300 liter/sec the power would be around 2200 watts

Other considerations would be to have a longer pipe run to increase the head, like 2200 for 22 * 1/3 = 7.3 feet = 2.2 meters

for 2.2 * 200 * 6 = 2640 watts

So you can see different ways to generate the power, AND notice that is GOOD for an IN-LINE propeller, that in winter the addition of a draft tube and a skirt may increase the power another 20 or so % .

basic design, and if you decide then more data is needed, it is doable if your aims and financial ( how deep the pocket is ) can handle it.

By the way, in USA and I believe in Canada, the CITIES change pipes periodically and those old pipes gotten by the asking or by the plastic price cost -- so think if your towns near you have such program .

You can make you own inline propeller with a Y coupler (the pipe - one side straight and the coupling at around 45 degree angle, I may have a sample in another hard disk.

Nando

[Ungrounded Lightning Rod]

2200 feet, not 1200, for stream length.  

[Nando]

1200 feet is the distance I have chosen because the pipe price for such enterprise may be too high.

I forgot to report the 1200 feet and reason.

I presented an average project than "the Ultimate"

Also, I limited the water volume usage to a more practical volume with the idea that about 20 to 25 % maximum of water utilization to cover "hidden" limitations that presently we are not aware.

He is looking for about 500 watts -- so I showed with just an increment of pipe diameter and/or length higher power is harvested.

This project if done has to be done carefully -- we do not know anything about the terrain and the stream behavior, as well as, the seasonal variations that are not well defined and established to insure a usable hydro electric system in a low head "starved" stream.

I always try to present something practical than the "maximum" capabilities of a site, which most of the time can not be realized.

Nando

[Nando]

I did mention 2200 feet and calculated with certain % water volume -- indirectly, I indicated a possible total stream length to attain a bit higher head -- if the 4 inches per 100 feet is stable along the stream in question.

Nando

[whatsnext]

Nando, Are you proposing that he divert the entire stream? Why not just build a dam at his prefered location? Say half the total drop high. 4"/100ft x 2200ft x .5= 44'. Once we find out the lay of the land we could determine how big his holding pond would be and how wide the dam would need to be and that's just to get half the available potential energy. Just because the stream is moving does not mean you can extract the kinetic energy. If you could the stream would stop and the water would just flow around your diverter.

[whatsnext]

OOPS! Forgot to divide by 12"/ft. His dam would need to be 3.66' tall. That would still back up 1100 feet of his stream and likely flood his entire property. I can't wait to see the photos because unless there are some very steep banks this guy is going to need a hell of a dam in order that it not washed away during high water times.

John..

[Nando]

No, 20 to 25 %, fish needs to be protected and also, during winter the pipe needs NOT to freeze.

Read my message carefully.

The Dam is a small one, all depends if that can be implemented, photographs are needed to define the profile of the stream, how is the bed ( large stones etc).

What I wrote is just a practical power generation and not the highest power possible.

First you need to understand the slope and how to capture the energy available.

I have made some like that, one with one meter head and 250 l/s in summer and 400 l/s in winter for 1500 and 2400 watts.

You are at the present guessing about he system -- I have not defined any thing -- I just informed about possibilities -- so time will say -- the stream bed will say yes or not to a small dam, all depends on the stream sides.

A dam with protection for high flows movements.

Nando

[Ungrounded Lightning Rod]

No prob.  Without the comment I just assumed it was an error rather than a deliberate choice of a more practical design.

By the way:  My own, non-expert, posting was intended just to see if there was enough energy in the water to be worth pursuing, given the targets, rather than to give a practical or affordable design or a reasonable expectation of the final output.  Also for practice.

I'm hoping that others - especially those with experience (such as yourself) - will walk us through how such estimates are really done and what the real problems are.

[DBuller]

Hey Flintcreek,

  I have a new design that creates power using the flow of water. Please take a look at http//www.WildWaterPower.com

-Dennis

[TomW]

Dennis;

Whats with that link?

takes me to mickeysoft.com and I hate anything Microsoft. Gee thanks!

Folks should check links before posting them as a courtesy to the readers.

T

[DBuller]

Ok, try http://www.wildwaterpower.com/index.html , for those of you who cannot figure out Mickeysoft.

[DBuller]

Ok, It seems I cannot figure out my own web page. It will not route with the www in it. So here it is http://WildWaterPower.com . No really.

[flintcreek]

Nando,

   I posted a photo, some drawings, and a few comments as a new posting entitled "RUN OF RIVER MICROHYDRO 2". Apparently the editors feel this is a bad idea (Making it a new posting, rather than continuously appending on to the old one.). They have left it up on the board, but disabled the comments.  Should I repost all this as an continuation of this thread? Thanks.

[Nando]

FLINTCREEK:

I think that it would be best for you to send the info directly to my email address that is in my heading of the message.

Change -at- to @ and -dot- to .

I see that you need to get more data.

This way the analysis will be done in a shorter manner, though the group will not be able to know how the steps are done to develop a site for a small hydro system RUN OF THE RIVER.

Nando