Electrical Question

[canfossi]

I am thinking about getting a micro-hydro system. I put on this board as I may get a bit quicker responce here. I currently have PV, the creek is year round and lots of flow and doesn't freeze where I'm planning on putting the trubine. The question is it's about 350 - 400 feet away from the house will this affect the electrical transmission over this great a distance, will there be a lot of line loss? Can it be done? I hope you can help. Thanks Chris

[ronbre]

bump, don't know

[tyusclan]

Not real sure what you're asking. Are you saying that your hydro-generation system would be about 350-400 from the house? If so, I would definitely increase the wire size, especially if you're talking DC. Not sure what voltage you'll be generating, but the lower the voltage, the more loss you'll experience over the run.

Hope this helps. We may can be more help with a little more info.

[artificer]

Start off with: "lots of flow and doesn't freeze where I'm planning on putting the turbine."

How much flow, and what is the drop? Lots of flow and no drop means very little energy.

What type of turbine are you thinking of using? What is the generator?

For long distances, you want the highest voltage generator you can get. If your generator puts out 12v, then you're going to have a LOT of loss over the distance. If you get something that puts out 240V, then it'll have 1/10th the losses. You have to find a charger that will take that 240V, but your line losses will be less. 60V charge controllers are easily found, so that might be a good goal.

The lower the voltage and the longer the distance, the larger your wire needs to be. A high power 12V system at 400' would need monster sized wire.

More information is needed to give specific answers.

Michael

P.S. Here's a low head, high flow system that uses a Chinese ST generator head that could be wired for either 110V or 220V. About 6000watts. Line losses wouldn't be prohibitive with this setup.

[ace admirer]

Hey!, that's a nice set up.....what is it? a Banki turbine?

[deaconjim]

To calculate lines losses, multiply the resistance of the wire times the square of the max current flow. It can easily be shown that the longer the run, the bigger the wire needs to be (Larger wire = lower resistance). A more effective way to reduce the losses is to raise the voltage, which lowers the max current.

[MELOC]

run the loss numbers and consider using ac vs. dc . ac will have less loss over the long run than dc. since a hydro system is usually constant, ac current may be feasible for certain dedicated circuits.

[canfossi]

Thanks, I'll have to ask more to see if it's feasible, maybe a wind generator would be better in this situation. Chris

[Billin]

I would go with a DC system backed up by battery at 125 volt or higher. AC will need to be converted anyway unless you regulate the turbine speed very closely. Convert the DC from the batteries back to AC if needed. You will be able to store some power for surges and have much simpler system.

[farminghandyman]

I would generate in AC, as most all "generators" are alternators to begin with, and then rectified to DC, then step it up via a transformer, and run the transmission line and then step it down again and then put it to DC,

[artificer]

Originally Posted by ace admirer

Hey!, that's a nice set up.....what is it? a Banki turbine?

Not my setup, I just wish I had the chance for hydro. Yes, its a Banki.

It was built from a set of plans from Village Earth, in their Appropriate Technology Library. You can actually get the information online here.

farminghandyman: I think you have one too many rectifiers in your description. Generate AC, step up voltage if not high already, transmit power over long distance, step down, rectify, charge battery

Canfossi: if you have the flow and head height, the hydro is going to be more reliable than wind since you said it doesn't freeze up in winter. One of the generator heads shown in the picture wired up to a stepdown transformer and rectifier feeding a charge controller will be a very nice system. Do you have any measurements of head height/drop, water speed, and area of flow?

Michael