Power from the pipes!

[On Guard for Thee]

Apparently they have a similar system now in Riverside Cal. that is being used to power street lights.

[Derek 2.0]

Yes but main pressure still has to be reduced before it goes into your home's system. It doesn't matter if main pressure is 300 psi or 100 psi, your home only needs 50 psi. One way of reducing that pressure is extracting energy from the flow.

I think you're missing the point......your domestic household pressure will decrease with extreme loads, likewise a larger city size system. This is why your hot water tank (is suppose to) has a vacuum breaker. If it didn't, and a negative pressure was to incur in the city system, like from broken water-main or the fire department using several hydrants, your household supply would be reversed and your hwt would be sucked dry and implode like a pop can. Like the reason as to why large facilities, farms, factories etc are required to have large backflow devices, to prevent a backflow of potentially contaminated water into the public system, caused by a sudden reduction in pressure, which can create a backflow.

Of course the point is moot, as the designers themselves of the pipe have clearly stated, it can only be used on gravity systems....

[TimG]

Apparently they have a similar system now in Riverside Cal. that is being used to power street lights.

In Germany they use coal power to run pumps that fill reservoirs and then use the reservoirs to generate hydro electricity. The process is inefficient, however, it allows politicians to pretend they are supporting "green" energy. At this point there is no evidence that these systems offer value other than creating the illusion of "renewable" power. Edited February 26, 2015 by TimG

[On Guard for Thee]

In Germany they use coal power to run pumps that fill reservoirs and then use the reservoirs to generate hydro electricity. The process is inefficient, however, it allows politicians to pretend they are supporting "green" energy. At this point there is no evidence that these systems offer value other than creating the illusion of "renewable" power.

No coal required in Riverside. Its all about the gravity. Thats where most of the power in Canada comes from. Its great stuff, pretty clean too.

[TimG]

No coal required in Riverside. Its all about the gravity.

You don't actually know how the water got into the reservoir to start with. Without this information you cannot make any claims about whether it is a net benefit or green washing. If it is a natural reservoir filled by rain then there could be a net benefit but only if that reservoir has more water than could possibly meet the demand. If the reservoir is filled by pumps there is no way it could be a net benefit.

[On Guard for Thee]

You don't actually know how the water got into the reservoir to start with. Without this information you cannot make any claims about whether it is a net benefit or green washing. If it is a natural reservoir filled by rain then there could be a net benefit but only if that reservoir has more water than could possibly meet the demand. If the reservoir is filled by pumps there is no way it could be a net benefit.

Ask yourself how does the water get into a hydro dam.

[Wilber]

I think you're missing the point......your domestic household pressure will decrease with extreme loads, likewise a larger city size system. This is why your hot water tank (is suppose to) has a vacuum breaker. If it didn't, and a negative pressure was to incur in the city system, like from broken water-main or the fire department using several hydrants, your household supply would be reversed and your hwt would be sucked dry and implode like a pop can. Like the reason as to why large facilities, farms, factories etc are required to have large backflow devices, to prevent a backflow of potentially contaminated water into the public system, caused by a sudden reduction in pressure, which can create a backflow.

Of course the point is moot, as the designers themselves of the pipe have clearly stated, it can only be used on gravity systems....

I'm not missing the point, you guys are having a tough time grasping the idea that water is delivered by volume and reservoir capacity is dictated by the amount of volume needed to supply the system. The pressure it exerts is dictated by weight not volume and the two don't match. Our tap pressures don't vary over a wide range of reservoir levels so obviously there is an excess of energy stored when levels are higher. Because there is an excess of pressure caused by the weight of the water column needed to ensure we have enough quantity to supply the system, we have to reduce the pressure in order to use it in our homes. Using a turbine to reduce that pressure allows us to tap some of the excess energy stored in the reservoir. Energy over and above that which is required to supply water to the system.

We pump water into towers and then gravity feeds the system. Again, the amount of water in the tower is dictated by the volume of water the system requires during high usage periods, not the amount of pressure required to deliver it. Except for periods of peak usage, there will be more energy contained in the tower's water than is required to force it through the system. A turbine will just allow us to recoup a bit of that energy. You guys insist on thinking the purpose of a water system is to optimize energy consumption, it isn't, it's purpose is to deliver water to consumers.

[overthere]

No coal required in Riverside. Its all about the gravity. Thats where most of the power in Canada comes from. Its great stuff, pretty clean too.

Really? Like where?

Many Canadian cities get their water from a river/lake. The river/lake is the low point in the system and water is pumped up to a reservoir for treatment as potable water. The potabe water is pumped under pressure to homes. Eventually the treated sewage(also pumped through the system into treatment plants) is taken by gravity back to the river.

[TimG]

The pressure it exerts is dictated by weight not volume and the two don't match.

Stop confusing static behavior with dynamic behavior. The equations are completely different and as soon as the water starts moving you need the equations for dynamic behavior. There is not much to talk about until you educate yourself on the difference between the two. Edited February 26, 2015 by TimG

[Derek 2.0]

You don't actually know how the water got into the reservoir to start with. Without this information you cannot make any claims about whether it is a net benefit or green washing. If it is a natural reservoir filled by rain then there could be a net benefit but only if that reservoir has more water than could possibly meet the demand. If the reservoir is filled by pumps there is no way it could be a net benefit.

It appears that the bulk of the reservoir is naturally sourced, but is supplemented by pumped ground water in Summer months.....

[On Guard for Thee]

Really? Like where?

Many Canadian cities get their water from a river/lake. The river/lake is the low point in the system and water is pumped up to a reservoir for treatment as potable water. The potabe water is pumped under pressure to homes. Eventually the treated sewage(also pumped through the system into treatment plants) is taken by gravity back to the river.

Wasnt talking about drinking water, talking about hydro power.

[Derek 2.0]

I'm not missing the point, you guys are having a tough time grasping the idea that water is delivered by volume and reservoir capacity is dictated by the amount of volume needed to supply the system. The pressure it exerts is dictated by weight not volume and the two don't match. Our tap pressures don't vary over a wide range of reservoir levels so obviously there is an excess of energy stored when levels are higher. Because there is an excess of pressure caused by the weight of the water column needed to ensure we have enough quantity to supply the system, we have to reduce the pressure in order to use it in our homes. Using a turbine to reduce that pressure allows us to tap some of the excess energy stored in the reservoir. Energy over and above that which is required to supply water to the system.

Our tap pressures (in Southern BC) are maintained by pumps..........

[Wilber]

Stop confusing static behavior with dynamic behavior. The equations are completely different and as soon as the water starts moving you need the equations for dynamic behavior. There is not much to talk about until you educate yourself on the difference between the two.

Balls, the amount of static pressure in the reservoir will determine how much dynamic pressure can be maintained in the system.

[TimG]

Balls, the amount of static pressure in the reservoir will determine how much dynamic pressure can be maintained in the system.

Nope. You cannot get energy out of the system without motion and extracting energy will reduce the kinetic energy (the flow) or the pressure. It is a basic conservation of energy problem. You seem to think you can get something for nothing. The world does not work that way.

[Wilber]

Our tap pressures (in Southern BC) are maintained by pumps..........

Those pumps are used to fill 22 reservoirs which deliver water to consumers by gravity, not pressurize the mains. If you just use pumps to pressurize the mains, you would need pumps that could handle the system's maximum demand instead of just using smaller pumps to fill reservoirs off peak. Definitely not energy efficient.

[Wilber]

Nope. You cannot get energy out of the system without motion and extracting energy will reduce the kinetic energy (the flow) or the pressure. It is a basic conservation of energy problem. You seem to think you can get something for nothing. The world does not work that way.

It's not getting something for nothing, it is recouping some of the energy used to pump water into a reservoir that is exerting pressure in excess of your needs. I don't know how many times I have to say this, a water systems purpose is to deliver a volume of water to a destination, not make more pressure than it takes to deliver it.

[TimG]

It's not getting something for nothing, it is recouping some of the energy used to pump water into a reservoir that is exerting pressure in excess of your needs. I don't know how many times I have to say this, a water systems purpose is to deliver a volume of water to a destination, not make more pressure than it takes to deliver it.

And you don't seem to understand that it is FLOW that transfers the energy - not the pressure. Extracting energy requires that kinetic energy be removed from the fluid and if you do that you can't meet the demand which causes a pressure drop no matter what the weight of the water in the reservoir is.

If you disagree please explain exactly how you think energy is transferred from the water into the generator.

Edited February 26, 2015 by TimG

[On Guard for Thee]

Apparently it isnt just the States that has figured this out.

http://www.cddhoward.com/nanaimo_water_supply.html

[Wilber]

And you don't seem to understand that it is FLOW that transfers the energy - not the pressure. Extracting energy requires that kinetic energy be removed from the fluid and if you do that you can't meet the demand which causes a pressure drop no matter what the weight of the water in the reservoir is.If you disagree please explain exactly how you think energy is transferred from the system into the generator.

You need to cause a pressure drop because the weight of the water you put into the reservoir is in excess of that which you need to deliver the volume of water you need to store. The pumps are using power to lift weight for a system that requires volume. You insist on looking at them as being the same thing. The turbine removes some of the kinetic energy that is excess of that required to move the water and in doing so, helps reduce the pressure to a level riquired by the system, rather than one dictated by reservoir level.

[TimG]

The turbine removes some of the kinetic energy that is excess of that required to move the water and in doing so, helps reduce the pressure to a level riquired by the system, rather than one dictated by reservoir level.

There is no "kinetic energy" in excess of what is needed to deliver the water in a system without a turbine because the flow in exactly matches the flow out. If there was "extra" kinetic energy this would represent a waste of energy and it could be eliminated by reducing the flow into the system. This would reduce the energy needed to keep the reservoir full and reducing the flow would be much more efficient than trying to extract the energy from the system later. Edited February 26, 2015 by TimG

[Wilber]

There is no "kinetic energy" in excess of what is needed to deliver the water in a system without a turbine because the flow in exactly matches the flow out. If there was "extra" kinetic energy this would represent a waste of energy and it could be eliminated by reducing the flow into the system. This would reduce the energy needed to keep the reservoir full and reducing the flow would be much more efficient than trying to extract the energy from the system later.

So you claim that water distribution systems are 100% efficient, there is no energy loss of any kind while the water is in the pipes.

Theconly way you can reduce the amount of energy used to put water into the reservoir is put less water into it, which means taking less water out. Nothing to do with pressure. One more time, this is a water system not an energy management system, it's function is to supply water not manage energy but if we can find a way to do a bit of that as well, we come out ahead.

Edited February 26, 2015 by Wilber

[On Guard for Thee]

Apparently the city of Victoria is considering a similar system

[TimG]

So you claim that water distribution systems are 100% efficient, there is no energy loss of any kind while the water is in the pipes.

I never made any such claim and parasitic loses are unavoidable and will continue to exist whether you stick turbines in or not. What I am saying is there is no deliberate inefficiency like you see with car breaking where the kinetic energy of car is converted to heat in order to stop the car. The only energy that needs to be put into the system at any given time is the energy required to deliver the water necessary to meet the current demand + whatever parasitic losses are inherent in the system. There is no excess.

One way to see this is to think about the system with a very low demand. In this situation almost no energy would be need to be put in and no energy would go out. So where does the energy used produce electricity come from? Magic? If there was "extra" energy as you claim the system would still require large inputs of energy even if demand is low. This is not the case. Water systems use very little energy when demand is low.

The only way you can reduce the amount, of energy used to put water into the reservoir is put less water into it, which means taking less water out.

Good we are making progress. Think about what you are saying: the only way to get energy out of the reservoir is to take water out. That means that any energy used for electrical generation must come at the expense of removing water from the reservoir. Your problem is you can't conceptualize how the lost energy affects the system. You assume that energy can come out of a system even if there is no additional energy being put in. This is pure nonsense. Edited February 26, 2015 by TimG

[On Guard for Thee]

I never made any such claim and parasitic loses are unavoidable and will continue to exist whether you stick turbines in or not. What I am saying is there is no deliberate inefficiency like you see with car breaking where the kinetic energy of car is converted to heat in order to stop the car. The only energy that needs to be put into the system at any given time is the energy required to deliver the water necessary to meet the current demand + whatever parasitic losses are inherent in the system. There is no excess.

One way to see this is to think about the system with a very low demand. In this situation almost no energy would be need to be put in and no energy would go out. So where does the energy used produce electricity come from? Magic? If there was "extra" energy as you claim the system would still require large inputs of energy even if demand is low. This is not the case. Water systems use very little energy when demand is low.

Good we are making progress. Think about what you are saying: the only way to get energy out of the reservoir is to take water out. That means that any energy used for electrical generation must come at the expense of removing water from the reservoir. Your problem is you can't conceptualize how the lost energy affects the system. You assume that energy can come out of a system even if there is no additional energy being put in. This is pure nonsense.

Water is removed from the reservoir 24 7. That happens when people turn on the tap. In this case the water just spins a turbine on its way to your coffee pot. What is so complicated about that I wonder...

[Wilber]

I never made any such claim and parasitic loses are unavoidable and will continue to exist whether you stick turbines in or not. What I am saying is there is no deliberate inefficiency like you see with car breaking where the kinetic energy of car is converted to heat in order to stop the car. The only energy that needs to be put into the system at any given time is the energy required to deliver the water necessary to meet the current demand + whatever parasitic losses are inherent in the system. There is no excess.

So parasitic losses are OK but losses that actually recoup energy are not. That's ridiculous. I'll keep saying this until if finally sinks in, this is a system built to deliver water, not balance energy use. The power inefficiency isn't deliberate, it"s a product of the need to deliver water.

Good we are making progress. Think about what you are saying: the only way to get energy out of the reservoir is to take water out. That means that any energy used for electrical generation must come at the expense of removing water from the reservoir. Your problem is you can't conceptualize how the lost energy affects the system. You assume that energy can come out of a system even if there is no additional energy being put in. This is pure nonsense.

Obviously I am getting nowhere. Tap pressures remain constant over the year regardless of reservoir level unless you have a severe water shortage and levels get dangerously low. The energy is contained in the water in the reservoir that you don't need to maintain that pressure. It's there whether you like it or not. Reservoirs store energy as well as water.

Whatever, all those cities going to this system and the companies building the components are idiots wasting their money because such a system can't work. Tim says so.

Edited February 26, 2015 by Wilber