Ballpark power available

[frackers]

I visited a friends place in the hills and they have a creek running through their property that at a guess is delivering about 10litres/sec at the bottom of their section. Since they will be building there sometime in the future, they asked me if water power was feasible.

I've not had a chance to explore where the springs are that feed it but making some assumptions that they could confine say 2 litres/sec into a pipe running in the creek bed and that they have a fall of 100m (its probably triple that but as I say I don't know what the flow is further up) how much power would that make available for a small turbine.

Cheers

[chainsaw]

Five things determine micro-hydro output

1. Head or vertical drop from source to the turbine nozzle.
   
2. Flow in gal or lit per minute passing through nozzle.
   
3. Diameter, length and condition of feeder pipe.
   
4. Turbine efficiency.
   
5. Wire run.
   
   

A quick formula: Watts=Net head X Usable flow/10. This assumes an efficiency of about 50%

This formula is in feet and gallons per minute.

Of course your efficiency can vary from 25% to over 75% depending type of generator,nozzel design, pipe friction,number of bends and runner type.

With 100m of head you would be most efficient with a pelton runner.

Assuming your estimates are correct  you have the potential for a nice micro-hydro site.

[Ungrounded Lightning Rod]

... And using that formula with the flow and head you quoted you get about 1.04 KW, running 24/7.

Rule of thumb is that an ordinary family house, without any special power saving effort but also without special loads such as electric heat, runs at about a KW average, or about 24 KWHr/day, or 730 KWHr/month.  (Check your bill to see how YOU do.)

So, yes, that's a VERY nice microhydro site.  A little effort on conservation, some batteries for load-leveling, and you can skip the grid tie.  B-)

[ghurd]

Great point!

Maybe OT food for thought.

"Micro".  As in Micro RE.

Micro Solar will barely run my desk lamp.  Small solar will, maybe, run a circuit in my home.

Micro wind can light LEDs or charge AAs.  Small wind will maybe run a circuit or 3.  A large wind system can run a lot more circuits.

Micro hydro, in a VERY nice spot, can maybe run my whole house.

Seems like the Micro name does not fit very well.

G-

[Flux]

Yes some of this terminology does seem stupid.

Commercial hydro goes up to Mw so at the watt level it is I suppose micro hydro but very confusing.

Is a microlight near darkness or a small plane?

Flux

[hiker]

check this out....

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

[Ungrounded Lightning Rod]

More than just MW.

Biggest is Grand Coulee, with three power plants totalling 6,809 MW (i.e. averaging 2,270 each).  Hoover's "nameplate capacity" is 2,080 MW.  Others are smaller, but major dams are in the thousand, not single, megawatt range.

So a one Kilowatt hydro is on the close order of one millionth of a high-end hydro dam.  Sounds like using "microhydro" for a KW dam/genny is right on the mark.

[Ungrounded Lightning Rod]

Biggest is Grand Coulee ...

Well, biggest hydropower instalation in the US, anyhow.  Biggest in the world is Itaipu Dam on the border between Brazil and Paraguay, which can produce 12,600 MW.

[frackers]

Just after posting the question I found the relevant equation and came to the same figure of 1kW - it seemed a bit too good to be true!

I shall pass on the good news and borrow a GPS handheld unit next time I visit the site to get more accurate measurements on fall and carry a bottle or two to check the flow rate (is there a calculation to convert beer bottles per second to kW?).

Looking a bit further ahead, does a micro-hydro system need any sort of speed regulator to compensate for the load to adjust for either constant voltage or constant frequency (or some combination thereof!!).

Cheers

[Ungrounded Lightning Rod]

Just after posting the question I found the relevant equation and came to the same figure of 1kW - it seemed a bit too good to be true!

Keep that in mind the next time you're considering installing a "water feature" with a pump, such as a fountain or decorative stream with waterfall.  Lifting water (or pressurizing a flow of it) takes a lot of energy.

Looking a bit further ahead, does a micro-hydro system need any sort of speed regulator to compensate for the load to adjust for either constant voltage or constant frequency (or some combination thereof!!).

Trying to regulate the volatage and frequency at the genny puts you in the same game as a power company.  They can afford to throw a lot of resources at the problem - and the amount of resources needed is the same whether it's for 1,000 watts or 1,000 megawatts.

IMHO unless you have a water power resource far larger than the maximum load you're ahead to skip trying to regulate it for direct application to the load (which could lead to frequency instability, brownouts, surges, and overvoltage events).  Instead use it as a charger for an otherwise typical battery bank/inverter system.  Let the inverter manufacturer deal with the problems of voltage and frequency regulation.