Micro Hydro Generation 1

[hanksmith]

I am looking for some good reading on the above mentioned subject.

Reason being is that I have an aunt/uncle that have a water fall on their property, it is already dammed, and they asked if there were any cost effective solutions to harness this power, they did not want to connect to grid, just to use the excess power to heat the barn, run some non-critical lights, etc....

I have not seen the water fall they speak about so I don't know about the head of the system or quantity of water.

Thanks

 

[itsmoked]

I have seen several micro generators. By far the easiest solution are the horizontal Pelton wheel versions. You can get them in 2 or 4 paddle versions depending on your wallet. Almost without exception the standard scheme now is for the wheel to drive an appropriate automotive alternator. Alternators can hit 20,000rpm off-the-shelf and you get to take advantage of an extreme mass production product stream.

The alternator feeds a battery and you run an inverter from the battery. This allows complete freedom from the technical hassles of maintaining a perfect speed thru gearing and flow control in the hydraulic realm.

Google 'micro hydro'. There is a lot out there.

The last one I saw drove the SCADA system on a remote PG&E hydro plant, (a couple of MW), in the Sierras. I thought it was clever as there was no power required so the SCADA could turn off the entire power plant and restart it.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[cranky108]

You really don't even need an inverter. 12v dc lights are easy to find at the automotive store. I have also seen heating elements for a hotwater heater that run on DC.

 

[roydm]

The only reason to step up the voltage is to minimise voltage drop.
Why not run the 3 phases from the alternator directly to your heating load.
Multipole permanent magnet motors from Fisher & Paykel washing machines are also very popular as low speed alternators.
Roy

 

[jraef]

Resistive heating elements don't know from AC or DC. But a 1000W heating element takes roughly 4A at 240V and it takes 80A at 12V! That is a fairly large 12VDC generator.

So here is the critical information you need to know before wasting any more time on this:

Head in Feet times Flow in GPM divided by 10 will equal the approximate Watts available. 100 gallons per minute of water falling 10 feet or 5 gallons per minute falling 200 feet through a pipe can generate 1000 watts (without transmission losses).

When you go visit your uncle, take a 1 gallon bucket and look at how fast it can fill. If it fills in 10 seconds, that is 60GPM; if it fills in 1 second, that is 600GPM (but I would then opt for a bigger bucket to be more accurate). Then look at the head (drop) you can utilize, meaning look at where you can install the generator and where you can tap off of the reservoir. Finally, look at the distance from where you can put the generator and where you want to use the power. Once you know how much power you can get from your waterfall, size the wire per code, then calculate the voltage drop you will see. Gather all that info, apply the math from above, then the final net result is the maximum amount of power you can effectively use. Most people are sorely disappointed. But you will most likely come away with a better appreciation for how much it takes to get the power into our grid system...


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376

 

[davidbeach]

I think you have a couple of extra '0's in there jraef. If I can do simple arithmetic, not always a valid assumption, 1 gallon in 10 sec would be 6gpm not 60gpm and 1 gallon in 1 sec would be 60gpm.

 

[jraef]

Ah, come on, what's a factor of ten between friends? ;-)


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376

 

[itsmoked]

Agreed!
As long as it isn't a magnitude...

Hey wait a minute!

Keith Cress
kcress -

http://www.flaminsystems.com

 

[MotorVib]

When I worked in the generator world there were a lager in of system like this used in Canada.

Chris

"In this house, we obey the laws of thermodynamics." Homer Simpson

 

[PHovnanian]

I worked with a few of these years ago (on the utility side, coordinating net metering setups with the generator's owners).

I don't know where you are or what the regulatory environment is, but it was my impression that the permitting process took an order of magnitude more effort than designing the plants.

Everybody from the EPA, local water rights boards, state and federal fisheries and wildlife, and local indian tribes are going to get involved.

 

[waross]

Automotive alternators start charging the battery at an engine speed of less than 1000 RPM and can go up to engine speeds of over 5000 RPM. A 100 Amp or 140 Amp alternator is not that large.
If you remove or replace the voltage regulator, over 50 volts at over 100 amps is doable. If you have need of hot water or space heating you can run the AC output directly to heating elements.

Bill
--------------------
"Why not the best?"
Jimmy Carter