Work is power times time, so the symbol is kWh, sometimes seen as kW-h. It's multiplication, not division as implied by "/".
Frank Leslie -----Original Message----- From: friend [mailto:[EMAIL PROTECTED] Sent: Tuesday, February 01, 2005 12:42 PM To: [email protected] Subject: Re: [microhydro] Confused about potential energy. Hi. You mixed up potential energy (kW) with done work (kW/h), the waterflow from level 1 to level ziro is much faster without the turbin.. so you changed waterflow speed into done work. With regards Friend_m ----- Original Message ----- From: ReadFamily To: [email protected] Sent: Tuesday, February 01, 2005 2:44 PM Subject: [microhydro] Confused about potential energy. I was thinking about the pumped water storage idea and then started to think about the energy in the system. If there is a full tank at the top and an empty tank at the bottom then the potential energy in the system is mgh (mass of water x gravitational constant x height difference). So if you let the water flow from top tank to bottom tank through a simple pipe then the potential energy is gone. (assuming bottom tank is at height 0). Now put the water back into the top tank and this time put a turbine in the pipe. The water flows from the top tank to the bottom tank and power is generated by the turbine and extracted from the system. But the difference in potential energy in the system is the same. All the water from the top is now in the bottom. Where did the energy that was extracted from the system by the turbine come from? I'm sure that the answer is somewhere in the statement in the first case where the water flows through a simple pipe. The potential energy in the system has changed - so where did the energy go? I dont know. Dominic Read Georgia, USA. [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 [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 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 --------------------~--> What would our lives be like without music, dance, and theater? Donate or volunteer in the arts today at Network for Good! http://us.click.yahoo.com/TzSHvD/SOnJAA/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/
