Hi Tom, I'm assuming that you're using GI or BI pipes since the maximum pressure at the bottom is about 85psi. Your penstock could handle up to 12L/s flow rate with reasonable efficiency.
For proper operation, the intake only requires a minimum depth of submergence 3x its diameter, theoretically 12" in your case, which makes your plan (4ft) more than sufficient. However, if you could immerse your intake deeper, you can use the pond as water storage during the dry weather. You can operate the system at full power (around 5kW @12L/s for pelton runners, or 3-4kW for crossflow runners) when water availability is sufficient. If the system is outfitted with multiple nozzles or with a spear valve, you can just adjust the flow rate to match what is available. However, generators and alternators are notoriously inefficient when operating at partial capacity. So if you have sufficient water storage capacity in your pond, you can operate your system for a few hours then wait for the pond to fill up before using it again. May I know your battery bank capacity and the total watt-peak capacity of the PV array? Are you planning to use your microhydro just for battery charging or have plans for other applications? Are you using your system as a hybrid system? Are you planning to fabricate your own turbine? Such info is also relevant in deciding what is best for your microhydro system. Eilrem thomas_a_phillips <[EMAIL PROTECTED]> wrote: To introduce myself, our OTG Solar home is located on the Cumberland Plateau, north of Chattanooga. We use Solar electric, propane and diesel with some wood for energy needs. Our home sits on a bluff that rises 150' above a raveen with a creek. We have a 1 acre pond up on the bluff that is fed by a wet weather stream that runs 8 or nine (winter)months. The out flow from the pond goes over the bluff to the creek below. I have surveyed a route for a 4" penstock from the spillway over to the bluff and down the slope to a suitable turbine location. Total length of the penstock will be around 800 ft. The Penstock will be buried from the pond to the edge of the bluff. The slope is too rocky to bury it from there to the turbine site, the last 200'. Difficulties will be the length of the penstock, the fact that it traverses a dip before droping over the bluff, the need for concrete thrust and slider blocks on the steep slope, and the distance of the turbine from the house, probably about 600'. I have two questions I'd like some input on. One, I think I can place the intake for the penstock out in about 4 feet of water in the pond away from the spill way. Is that a good plan? And two, It is a wet weather stream that drains about 50 acres. This year has been unusualy wet, so the stream has almost not stopped running. But other years we have seen little or no flow in July, August and September. (Of course the solar panels crank then). How are these periods of intermittant flow handled? Does it require constant adjustment, or do you just shut it down till you have sufficient flow? Thanks for your input and glad I found this site, Tom __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com [Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor --------------------~--> Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home page http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/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/
