Hi Dominic Read,
Not too sure, what point you were trying to make here. To answer the question: Is it possible to extract energy from flowing water? Yes, it is possible. Agreed, the speed of the water flowing will depend on the gradient of the river. Ghanashyam -----Original Message----- From: ReadFamily [mailto:[EMAIL PROTECTED] Sent: Tuesday, November 09, 2004 6:23 PM To: [EMAIL PROTECTED] Subject: Re: [microhydro] Re: Newbie question: energy estimation from flow rat e Are we fooling ourselves a little with pretending that there is a difference between removing kinetic energy from a flowing stream and driving a turbine with a high head using the potential energy of the water. In a stream there is a relationship between speed of flow and difference in height. It may be complex, but its there, and we know it intuitively to some extent. If the stream is level then its a lake - it doesnt move - as the difference in height grows, so does the horizontal component of gravity and so the horizontal force applied to the water, hence its acceleration. The water accelerates to the point where the forces holding it back are the same as the forces pulling it downstream. When we talk about using the streams kinetic energy, then what we are doing is slowing down the water, and in doing so we back it up to some extent. The more kinetic energy we extract from a stream the more we slow down the flow of the water, and the more water is backed up. Since the water upstream of the energy conversion device is now higher than the water downstream then isnt that the same as using a very small difference in water height? When we use a pelton wheel or similar driven from a water jet with a large head then what we are doing is using the difference in height to accelerate the water and then using the kinetic energy of that water to turn the turbine. The fact that before the water flowed through the nozzle it had been in a pipe and then in settling tanks and then in a flowing stream doesnt really change what we are doing. I'm still figuring this out so I may have simplified it or complicated it, but that's my understanding right now. Dominic Read Georgia, USA ----- Original Message ----- From: Ranjitkar, Ghanashyam To: '[EMAIL PROTECTED]' Sent: Friday, November 05, 2004 10:18 AM Subject: RE: [microhydro] Re: Newbie question: energy estimation from flow rat e Hi there, It is possible to extract energy from the flowing water. The potential energy will depend on the speed of the water current, normally given in meter per second. Just like in wind power, higher the speed higher the power output form the turbine. The turbine that you are looking for is commonly knows as water current turbines, and many are still in prototype stages. [Non-text portions of this message have been removed] 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 ------------------------ Yahoo! Groups Sponsor --------------------~--> $9.95 domain names from Yahoo!. Register anything. http://us.click.yahoo.com/J8kdrA/y20IAA/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/
