Hi All, This probably sounds a little outdated, for low head schemes where the issues are: fish passage, flooding, debris, large flow variations - we install water wheels. If anybody is interested in pictures of the set up for a small 1.8m wheel, coupled to a Smart Drive email me and I can send some pictures. It can do up to 500 W but most of the time runs at about 200 Watts dropping down to 100 during low summer flows. It cost very little to make and has been very reliable. The high output at low rpm of the Smart Drive means that a simple gearbox from motorcycle chain can be made cost effectively. Conversion efficiency is around 50% which for a low head low power scheme with a 30:1 gearbox ratio is good.
We recently ventured into using a PowerPal propeller turbine at a 1.8m site but immediately had the problem with debris, fish and turbine performance problems. It cost much more to engineer a solution to these than the gearbox of the water wheel. During floods the wheel runs nearly half submerged still at about half full output power. I'm not aware of any other device able to overcome all these issues. Regards Michael Lawley Renewable Energy Engineer EcoInnovation 671 Kent Road R.D.1 New Plymouth New Zealand Phone: (NZ) 06 752 2765 Web site: www.ecoinn.co.nz email: [EMAIL PROTECTED] ----- Original Message ----- From: davidrichardmann To: [EMAIL PROTECTED] Sent: Thursday, September 16, 2004 9:30 PM Subject: [microhydro] Archimedes Screw Micro Hydro Dear Mr Thomas K�hli I read with interest the infomation about your micro hydro plant in Switzerland using an archimedes screw. I have never heard of this being used before, and am curious as to why it was chosen. Efficiency at low head? Fish protection? Cost? Do you have any more details of the project available? I am looking at ways to install a low head scheme (1.8m) in a river where fish protection is a major problem. What I really need is a machine that will extract the water power efficiently, whilst still permitting the safe passage of small fish through the unit! Thanks for your help Dave Mann 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 Sponsor ADVERTISEMENT ------------------------------------------------------------------------------ Yahoo! Groups Links a.. To visit your group on the web, go to: http://groups.yahoo.com/group/microhydro/ b.. To unsubscribe from this group, send an email to: [EMAIL PROTECTED] c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. [Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor --------------------~--> Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. Now with Pop-Up Blocker. Get it for free! http://us.click.yahoo.com/L5YrjA/eSIIAA/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/
