TimG Posted February 25, 2015 Report Posted February 25, 2015 (edited) Whether it comes from a natural reservoir or is pumped into a storage facility is not relevant.It is extremely relevant. Any man made system will be design to perform a task and should not have any capacity in excess of what is needed for that task. A natural reservoir simply takes advantage of energy stored by nature that would otherwise be wasted. So we can dam a river and generate hydro because the water was going to flow downhill into the ocean no matter what humans do. A water tower, OTOH, has no need to let water flow unless humans need it so there is no "excess flow" to be exploited. Edited February 25, 2015 by TimG Quote
On Guard for Thee Posted February 25, 2015 Report Posted February 25, 2015 The poster is either a troll who likes provoking people or an idiot who has no interest learning. We know who the idiot is who wont seem to learn. How often, for starters, do you think water isnt flowing in the pipes in Portland, Oregon... Quote
Wilber Posted February 25, 2015 Report Posted February 25, 2015 It is extremely relevant. Any man made system will be design to perform a task and should not have any capacity in excess of what is needed for that task. A natural reservoir simply takes advantage of energy stored by nature that would otherwise be wasted. So we can dam a river and generate hydro because the water was going to flow downhill into the ocean no matter what humans do. A water tower, OTOH, has no need to let water flow unless humans need it so there is no "excess flow" to be exploited. I think you are looking ar this the wrong way. This a water supply system, not a power generation system. A water supply system requires a certain capacity to look after a wide range of demand. It doesn't matter whether that capacity was put there by nature or pumps, once the water is in the reservoir, that's where the energy is stored. If the reservoir was filled by pumps, it is even more important to try and recover some of that energy if we can. Quote "Never trust a man who has not a single redeeming vice". WSC
TimG Posted February 25, 2015 Report Posted February 25, 2015 This a water supply system, not a power generation system. A water supply system requires a certain capacity to look after a wide range of demand.What you seem to miss is that any water that flows into the pipes MUST flow out. So if there is no demand there is no flow and no way to tap that power no matter how much excess capacity may exist. Quote
On Guard for Thee Posted February 25, 2015 Report Posted February 25, 2015 (edited) I think you are looking ar this the wrong way. This a water supply system, not a power generation system. A water supply system requires a certain capacity to look after a wide range of demand. It doesn't matter whether that capacity was put there by nature or pumps, once the water is in the reservoir, that's where the energy is stored. If the reservoir was filled by pumps, it is even more important to try and recover some of that energy if we can. Makes very good sense. If you are near the mountains and have the assist of natural gravity you really do well. But as you, once you point out, once you have paid to pump water up into a tower, may as well get some benefit from that latent energy. Edited February 25, 2015 by On Guard for Thee Quote
Wilber Posted February 25, 2015 Report Posted February 25, 2015 (edited) What you seem to miss is that any water that flows into the pipes MUST flow out. So if there is no demand there is no flow and no way to tap that power no matter how much excess capacity may exist. Obviously but if the sun don't shine and the wind don't blow, solar and wind generation don't work either. That doesn't make them useless forms of power generation. Edited February 25, 2015 by Wilber Quote "Never trust a man who has not a single redeeming vice". WSC
On Guard for Thee Posted February 25, 2015 Report Posted February 25, 2015 What you seem to miss is that any water that flows into the pipes MUST flow out. So if there is no demand there is no flow and no way to tap that power no matter how much excess capacity may exist. And how often in a big city do you think there is no demand... Quote
TimG Posted February 25, 2015 Report Posted February 25, 2015 (edited) Obviously but if the sun don't shine and the wind don't blow, solar and wind generation don't work either. That doesn't make them useless forms of power generation.And if the water is flowing then it must exactly match the demand. If you start taking energy out of the system the pressure drops and the system malfunctions no matter how low the demand unless you increase the flow which will require that potable water be wasted. Edited February 25, 2015 by TimG Quote
Wilber Posted February 25, 2015 Report Posted February 25, 2015 And if the water is flowing then it must exactly match the demand. If you start taking energy out of the system the pressure drops and the system malfunctions unless you increase the flow which will require that potable water be wasted. Again, you are looking at this as a power generation system, not a water system. As already pointed out, our homes have pressure reducing valves to drop main pressure to an acceptable level for ou homes. Why not use a turbine to extract some of that energy not needed to supply water. Quote "Never trust a man who has not a single redeeming vice". WSC
TimG Posted February 25, 2015 Report Posted February 25, 2015 (edited) Again, you are looking at this as a power generation system, not a water system. As already pointed out, our homes have pressure reducing valves to drop main pressure to an acceptable level for our homes.Pressure reducing pipes do not remove energy from the system (other than conversion losses). Take energy out of the system to produce electricity and you will either end up with acceptably low pressure in your house or you have to increase the input pressure which takes energy. This is a simple conservation of energy problem. The only way you can produce power is if energy is currently being wasted and you simply redirect the waste (e.g. regenerative breaking). In the water system they do not waste power. If water is not needed the potential energy of the water in towers is stored until it is needed. There is no 'waste energy' to tap. Edited February 25, 2015 by TimG Quote
Wilber Posted February 25, 2015 Report Posted February 25, 2015 Pressure reducing pipes do not remove energy from the system (other than conversion losses). Take energy out of the system and you will either end up with acceptably low pressure in your house or you have to increase the input pressure which takes energy.This is a simple conservation of energy problem. The only way you can produce power is if energy is currently being wasted and you simply redirect the waste (e.g. regenerative breaking). In the water system they do not waste power. If water is not needed the potential energy of the water in towers is stored until it is needed. There is no 'waste energy' to tap. That's the point, energy is being wasted because this is a water supply system not an energy supply system. It's purpose is to supply water. Quote "Never trust a man who has not a single redeeming vice". WSC
TimG Posted February 25, 2015 Report Posted February 25, 2015 (edited) That's the point, energy is being wasted because this is a water supply system not an energy supply system. It's purpose is to supply water.You are completely wrong. There is no waste in an well designed water system. Any energy that goes into the system is used to keep the system functioning within operating parameters. Take the energy out and the system would malfunction. Any engineers who designed a water system that wastes energy would be incompetent. Edited February 25, 2015 by TimG Quote
On Guard for Thee Posted February 25, 2015 Report Posted February 25, 2015 Pressure reducing pipes do not remove energy from the system (other than conversion losses). Take energy out of the system to produce electricity and you will either end up with acceptably low pressure in your house or you have to increase the input pressure which takes energy. This is a simple conservation of energy problem. The only way you can produce power is if energy is currently being wasted and you simply redirect the waste (e.g. regenerative breaking). In the water system they do not waste power. If water is not needed the potential energy of the water in towers is stored until it is needed. There is no 'waste energy' to tap. Generators at hydro dams are brought off and on line based on water flow available. All this system would do is do that more often based on current flow demands, rather than seasonal river levels. Quote
Wilber Posted February 25, 2015 Report Posted February 25, 2015 You are completely wrong. There is no waste in an well designed water system. Any energy that goes into the system is used to keep the system functioning within operating parameters. Take the energy out and the system would malfunction. Any engineers who designed a water system that wastes energy would be incompetent. A water system needs to supply an adequate amount of water at peak demand. That requires head pressures far above those required during normal demand. I'll say it one more time, the purpose of water systems is to supply water, not optimise energy consumption. Quote "Never trust a man who has not a single redeeming vice". WSC
TimG Posted February 25, 2015 Report Posted February 25, 2015 (edited) Generators at hydro dams are brought off and on line based on water flow available. All this system would do is do that more often based on current flow demands, rather than seasonal river levels.In the case of hydro, mother nature is providing the energy by moving water from the oceans to the mountains. If there was no dam the energy would be turned into kinetic energy as the water rolls downhill. This is waste energy that can be harvested. There is no waste energy in a water system. Edited February 25, 2015 by TimG Quote
TimG Posted February 25, 2015 Report Posted February 25, 2015 (edited) A water system needs to supply an adequate amount of water at peak demand. That requires head pressures far above those required during normal demand. I'll say it one more time, the purpose of water systems is to supply water, not optimise energy consumption.And I will say it one more time: the energy that needs to be put into the system to maintain the pressure *decreases* when demand decreases. Therefore there is no waste when demand is low. Take energy out when demand is low and you will have to increase the energy that goes in. Edited February 25, 2015 by TimG Quote
On Guard for Thee Posted February 25, 2015 Report Posted February 25, 2015 In the case of hydro, mother nature is providing the energy by moving water from the oceans to the mountains. If there was no dam the energy would be turned into kinetic energy as the water rolls downhill. Thats correct.but thats not what is happening here, exactly. The small reduction in your water tap to drive theses turbines would not be any bother to you while you are washing the dishes etc... Quote
Wilber Posted February 25, 2015 Report Posted February 25, 2015 mG" post="1034295" timestamp="1424838242"]And I will say it one more time: the energy that needs to be put into the system to maintain the pressure *decreases* when demand decreases. Therefore there is no waste when demand is low. Take energy out when demand is low and you will have to increase the energy that goes in. Main pressures are higher than those needed in our homes. The only way to reduce that pressure is to reduce flow. Doing it with a turbine can recover some energy that is stored in the system. Again, the purpose of a water system is not to optimise energy use, it is to supply water to your home. Quote "Never trust a man who has not a single redeeming vice". WSC
TimG Posted February 25, 2015 Report Posted February 25, 2015 Main pressures are higher than those needed in our homes. The only way to reduce that pressure is to reduce flow.You can reduce the pressure by increasing the speed of water in the pipes. This can be done with minimal energy loss much like a transformer can reduce voltage to the levels needed inside a home. There is no waste energy to take for electricity generation. Quote
Wilber Posted February 25, 2015 Report Posted February 25, 2015 You can reduce the pressure by increasing the speed of water in the pipes. This can be done with minimal energy loss much like a transformer can reduce voltage to the levels needed inside a home. There is no waste energy to take for electricity generation. If you increase the speed, you increase flow and increase consumption. Quote "Never trust a man who has not a single redeeming vice". WSC
TimG Posted February 25, 2015 Report Posted February 25, 2015 (edited) If you increase the speed, you increase flow and increase consumption.The speed of the water only matters when a tap is turned on. If it is turned off there is no flow and no water consumption. It is like a transformer: dropping the voltage means the output current is increased compared to the input but if there is nothing attached to the transformer that needs the power the input and output current drops to zero. The transformer itself wastes very little energy. The same is true of the turbines that drop pressure in water lines. Edited February 25, 2015 by TimG Quote
On Guard for Thee Posted February 25, 2015 Report Posted February 25, 2015 The speed of the water only matters when a tap is turned on. If it is turned off there is no flow and no water consumption. It is like a transformer: dropping the voltage means the output current is increased compared to the input but if there is nothing attached to the transformer that needs the power the input and output current drops to zero. The transformer itself wastes very little energy. The same is true of the turbines that drop pressure in water lines. So all you have to worry about is if everybody in Portland turns their taps off. Not likely to happen. Quote
Wilber Posted February 25, 2015 Report Posted February 25, 2015 The speed of the water only matters when a tap is turned on. If it is turned off there is no flow and no water consumption. It is like a transformer: dropping the voltage means the output current is increased compared to the input but if there is nothing attached to the transformer that needs the power the input and output current drops to zero. The transformer itself wastes very little energy. The same is true of the turbines that drop pressure in water lines. If you decrease voltage, you need a larger gauge wire to provide the required wattage. If you decrease pressure you need a larger diameter pipe to flow the same amount of water. Since we can't change pipe diameter, reducing pressure will result in a reduction of flow and an increase in speed will require more pressure and result in an increase in flow. Quote "Never trust a man who has not a single redeeming vice". WSC
TimG Posted February 25, 2015 Report Posted February 25, 2015 (edited) If you decrease voltage, you need a larger gauge wire to provide the required wattage. If you decrease pressure you need a larger diameter pipe to flow the same amount of water.Sure. If the same amount of water came off the mains at the same pressure you would only need tiny pipes. The pipes are sized to handle the amount of water required by a household at the higher speed/lower pressure. The system has been carefully designed to work with minimal losses. No matter how much you wish there is no wasted energy that can diverted for electricity generation. Edited February 25, 2015 by TimG Quote
Wilber Posted February 25, 2015 Report Posted February 25, 2015 (edited) Sure. If the same amount of water came off the mains at the same pressure you would only need tiny pipes. The pipes are sized to handle the amount of water required by a household at the higher speed/lower pressure. The system has been carefully designed to work with minimal losses. No matter how much you wish there is no wasted energy that can diverted for electricity generation. You need higher pressure to provide higher speed in a given diameter pipe. Because we have to reduce main pressure which means reducing flow, there is excess energy stored in the system that is not required to supply water. On edit. Let me qualify that. At times other than peak demand, there is excess energy stored in the system. At peak, full main pressure might be required to provide enough flow to meet demand. Edited February 25, 2015 by Wilber Quote "Never trust a man who has not a single redeeming vice". WSC
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