hydro turbine 100 kw

to calculate the volumn of water in a river as large as yours, you will need to you will need to measure the depth of the river to establish a bottom profile/ cross sectional area. Then by measuring the current speed, you can calculate the total volume per second. Here is the location of a .PDF file that will tell you how to do it.
http://www.absak.com/tech/headflow.pdf

Meanwhile, from your brief description, it is highly unlikely that you will be able to get anything close to 100kw from this source. Is that a real number or something that you just would like to have ?

LAST EDITED ON May-26-06 AT 01:54 PM (EST)

The .pdf file are read with the Adobe acrobat reader. You can download it from
http://www.adobe.com/products/acrobat/readstep2.html

Water wheels are better for mechanical work than generating electricty. Gearing the wheel speed up to generator speed eats a lot of power.
You may want to visit
http://www.waterwheelfactory.com/

According to their numbers a water wheel 12 feet in diameter with 6.68 cu ft a second (3000 gals/min) generates about 7.7 hp.
With the gearing losses, that would generate something around 3kw.

LAST EDITED ON May-27-06 AT 11:55 AM (EST)

"the cross section of the lowest point of
river is 2 ft deep x 30 ft wide. and has a flow
of 5ft a second."

I am not sure whether that means that the deepest point in the 30 feet is 2 feet deep, or whether you mean that it averages 2 feet deep for the 30 foot width.  

If it averages 2 feet deep, that would be a flow of 300 cu feet a second. If 2 feet is just the deepest point, and it shallows rapidly, you may only have 100 cu feet a sec.  But the good news is that a river that size should have a stream guage on it. If you would give me the name of the river and the name of a town nearby (and state), I can look for stream guage data on it.

Another question for you. In rereading your need for the 100kw, I think you have taken the total of all loads and sized your generator based on that. I am thinking that you may get by with something smaller, which would cut down on the cost.  Do you have a current electric bill for this property, or is this something in the planning stage ? If you have a electric bill, What is the total killowatt hours billed per month ?

You are probably at a point where you should get someone local (either a hydro engineer or an alternative energy specialist) to take a look at your problem.

I think it is very doubtful that you will be able to produce anything near 100kw. But that is a remote judgement based solely on verbal descriptions. Someone local could take a look at the site and might come up with another opinion.

The other thing the local person could do is to help you refine your power requirement. 100kw is a ton of power. Your actual need could be much less.  "basicly working on a average sized factory around auckland which seems to be on average around 100 kw" could have you looking for something that may be twice the size of your actual needs.

Tum,if your property runs along the river, you could consider running a pipe from somewhere upstream down to where you are in order to gain some head pressure...

Just a thought. Maybe someone could elaborate on this?
It would take less electrical energy to power an electrolizer to produce hydrogen which could then be burned in order to produce the Btu's needed for the kiln and oven. I am geussing that the kiln might run day and night but that the oven would not. As for the home... go solar with water genny as back up and burn hydrogen or reclaim heat from kiln and or oven for; heat, cooking, water heater, lighting, refrigeration, whatever LPG or NG can do hydrogen can do.
Maybe this is all a little to futuristic. I mean its not like we can go down to our local home improvement store and buy it off the shelf now can we? Shhuh, cant even do that with any of the RE mediums. I geuss its just as well they havent gotten ahold on them yet. I can see it now... a $300 PV module that sells for $450 now because of this so called shortage of raw materials, would sky rocket to 700 bucks if sold at every home improvement store but not just PV.

the length of the pipe effects the pressure due to friction losses. The over height from one end to the other gives you your head pressure. Head pressure minus the friction losses gives you the total pressure.