Daniel,
I am not a microhydro expert, but I have been an electrical engineer for 30 years. I can see where your are having some trouble with the different suggestions. You are looking at two basic practical methods: (1) Generate the power at approximately 60 volts DC, then send it up two #2 wires to your batttery bank, where it arrrives (after voltage drop losses in the wire) at the correct charging voltage. (2) Generate the power at 120 or 240 volts AC, using a generator that has some type of expensive troublesome speed controller (governor) to keep the frequency at approximately 60 HZ, then transmit it up to your power station, where you then step it down to a lower voltage using a transformer, then change it back to DC using some type of "rectifier". A rectifier is an electronic device that converts alternating current to direct current. Now, both Methods 1 and 2 have power losses involved. For Method 1, you have the resistance of the wire, which is determined by the size of the wire. The larger diameter of the wire, the smaller the losses. This is the method that I would use, because over a long period of time, your costs will be less. You can shop around and find some used wire of a large size that, at 48 volts DC, will allow a very small loss, even at 800 feet. Once you get the wire paid for, you have eliminated three possible maintenance headaches: speed governor, transformer, and a rectifier. For a DC generator, you do not need a speed controller, because a faster or slower speed just causes a change in the magnitude of the voltage. There is no alternating frequency to worry about, so your generator speed can be controlled by manually adjusting the the volume of water going to the turbine. For Method 2, any time that you convert power from one form to another, there are losses because there is not a conversion method that is 100% efficient. This rule is based on the basic laws of physics. So at the transformer you will probably have, for this small size, about a 5% loss. Then as you go from AC to DC, you will have another 3 to 5% loss in the rectifier. Additionaly, you will have 3 new devices to maintain and service. The transformer will last many years without attention, but eventually the winding insulation will peel off and will short out. The other two electronic devices may fail at any time due to the heat caused by operation. Now, if you look at Method 1, using large wire for a DC voltage transmission, it does not look so bad to me. Wire is one of the least likely devices to fail. If you install the wire underground in a 1.5 inch diameter PVC plastic conduit, it will last for 50 years without problems. ------------------------ Yahoo! Groups Sponsor --------------------~--> In low income neighborhoods, 84% do not own computers. At Network for Good, help bridge the Digital Divide! http://us.click.yahoo.com/EA3HyD/3MnJAA/79vVAA/FGYolB/TM --------------------------------------------------------------------~-> Does your company feature in the microhydro business directory at http://microhydropower.net/directory ? If not, please register free of charge and be exposed to the microhydro community world wide! NOTE: The advertisements in this email are added by Yahoogroups who provides us with free email group services. The microhydro-group does not endorse products or support the advertisements in any way. More information on micro hydropower at http://microhydropower.net To unsubscribe: send empty message to [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/microhydro/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
