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jacee

Power from the pipes!

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Additionally, cheap, off peak electricity is used to fill the towers up and the pipe turbines generate more expensive peak power as the towers provide pressure during the peak hours from 5 am - 9 am. Just like systems designed to capture and harness waste heat, this system provides free electricity by recouping some energy that must be used anyway.

I think, as you’ve indicated, it’s not a matter of pressurization, as that already has to occur (be it a gas or liquid) to transport the material through the pipe distribution network, but how much actual electricity is generated. As already pointed out, modern digital water/gas meters are already powered in such ways, but the actual power generation is significantly low voltage…….the question then becomes, as indicated by Tim, if it’s worth the actual overall capital outlay………I would assume said money would be better spent by incentives to reduce consumption, like credits to replace inefficient toilets or light bulbs.

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I dont know where you live but my, and most city water runs between 45 - 60 PSI. Anything above 80 will do damage. The articles on to Portland system Ive see so far havnt yet explained how much of a drop it might or does cause. However I would suspect a city of its size might just have a few engineers kicking around who would have given this some thought.

No, you don't know what you're talking about.......anything over 80 psi will do damage to fixtures within your home, which is why modern homes have a PRV on the inlet pipe where the water service enters the home.......City pressure has to be higher or it wouldn't be able to contend with elevations over 33 ft above sea level, likewise fire hydrants would trickle, when opened, like a garden hose........

Edited by Derek 2.0

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I think, as you’ve indicated, it’s not a matter of pressurization, as that already has to occur (be it a gas or liquid) to transport the material through the pipe distribution network, but how much actual electricity is generated. As already pointed out, modern digital water/gas meters are already powered in such ways, but the actual power generation is significantly low voltage…….the question then becomes, as indicated by Tim, if it’s worth the actual overall capital outlay………I would assume said money would be better spent by incentives to reduce consumption, like credits to replace inefficient toilets or light bulbs.

Tim also mistakenly suggested that such pipes increase energy requirements. The new energy producing pipes are a no brainer on new construction or when tower pipes need replacing; however, more cost info would be required to determine there is any value to retrofitting towers.

I assume you're right about reducing consumption though. Reducing energy consumption is almost always significantly more cost effective than new generation. It is unfortunate that the Harper government terminated the cost effective ecoEnergy Retrofit program as it was efficiently reducing consumption, energy bills and creating local jobs.

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No, you don't know what you're talking about.......anything over 80 psi will do damage to fixtures within your home, which is why modern homes have a PRV on the inlet pipe where the water service enters the home.......City pressure has to be higher or it wouldn't be able to contend with elevations over 33 ft above sea level, likewise fire hydrants would trickle, when opened, like a garden hose........

Which is exactly my point. There is a differential between what comes down the mains and what comes out my tap. There could be enough excess in that margin to produce some green electricity.

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Which is exactly my point. There is a differential between what comes down the mains and what comes out my tap. There could be enough excess in that margin to produce some green electricity.

The pressure of the water doesn't play into the generation of power, hydro dams utilize water at atmospheric pressure (~5 psi dependent on elevation in relation to sea level), but by volume of flow.......

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The pressure of the water doesn't play into the generation of power, hydro dams utilize water at atmospheric pressure (~5 psi dependent on elevation in relation to sea level), but by volume of flow.......

Water flowing through a pipe will spin a generator turbine wheel. Thats how a hydro dam works. Same principal in a water main.

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Tim also mistakenly suggested that such pipes increase energy requirements. The new energy producing pipes are a no brainer on new construction or when tower pipes need replacing; however, more cost info would be required to determine there is any value to retrofitting towers.

I don't know that it would be a no brainer.......what is the cost of not only retrofitting said pipes, but also maintaining them, versus a "regular pipe" that is left as is until it leaks?

That is where cost benefit comes into play.

I assume you're right about reducing consumption though. Reducing energy consumption is almost always significantly more cost effective than new generation. It is unfortunate that the Harper government terminated the cost effective ecoEnergy Retrofit program as it was efficiently reducing consumption, energy bills and creating local jobs.

Reducing consumption doesn't need to be a government carrot though........for example, if your domestic water is metered (if its not currently, it will be one day) changing old 12 lpf toilets with 6 or 4.8 lpf water saver toilets is the no brainer for the home owner.......

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Water flowing through a pipe will spin a generator turbine wheel. Thats how a hydro dam works. Same principal in a water main.

Did I say different? :rolleyes:

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Reducing consumption doesn't need to be a government carrot though........for example, if your domestic water is metered (if its not currently, it will be one day) changing old 12 lpf toilets with 6 or 4.8 lpf water saver toilets is the no brainer for the home owner.......

Government carrots hasten retrofits which are far more efficient than increasing capacity. Why kill a program that was efficient, effective and aided job creation? That's just stupid. Homeowners with the means should certainly retrofit on their own. I like the idea of low interest energy efficiency loans, payable through property tax collection, that can be passed on to new owners. Such programs make investment in efficiency accessible and worthwhile, even if an owner is unsure how long they plan to hold on to a particular residence.

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Sewage treatment plants are built at the bottom of any hills so gravity will transport the sewage.

Sewage treatment plants are very expensive undertakings, and nobody wants them in their neighbourhood. That means that in metro areas very large plants are common, and that means that effluent is often pumped long distances. It is advantageous to use gravity, but often that cannot happen. Sewage plants are often built not at the bottom of hills, but on plains so they can have large settling ponds. The last leg of the disposal may involve a vertical drop into a river.

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Government carrots hasten retrofits which are far more efficient than increasing capacity.

Is there any real evidence to support that though? In my personal experience, when I replaced the older toilets in my previous home and rental, I received a rebate of $25 per toilet from the city, or $125 refunded for outlaying several thousand dollars in new toilets.....clearly a negative return on investment in and of itself. My incentive though was nearly having my annual water bills, recouping the several thousand dollar initial outlay in several years............As I said, a cost/benefit, one not motivated on spending ~$1875 on toilets versus ~$2000, but actual long term savings.

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You're right that the energy has to come from somewhere, but that's about it. If these turbines were placed in water mains, rather than in water towers, then you would have a point. It's not the speed of the water moving down the tower that provides pressure for peak water demand, but rather the height and volume.

It does takes more energy to pump the water up to the top of the tank than can be extracted from the falling water. So, if the sole purpose of water towers was to generate electricity it would be a net loser. However, the towers are already necessary to provide peak water demand and minimize the size of municipal water pumps. Hence, water pipe turbines simply recoup some of the electricity that must be spent anyway.

Additionally, cheap, off peak electricity is used to fill the towers up and the pipe turbines generate more expensive peak power as the towers provide pressure during the peak hours from 5 am - 9 am. Just like systems designed to capture and harness waste heat, this system provides free electricity by recouping some energy that must be used anyway.

Actually according to the article I read they are in the main. There are 4 in a section of 42 inch main that is gravity fed and so far testig has shown no adverse effect to flow. And, those 4 gens. are capable of providing wattage to power 150 homes.

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Actually according to the article I read they are in the main. There are 4 in a section of 42 inch main that is gravity fed and so far testig has shown no adverse effect to flow. And, those 4 gens. are capable of providing wattage to power 150 homes.

so that must be from a reservoir to a pumping facility. Why not just put in conventional turbines and create power for a thousand homes?

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Run of river hydro installations are more efficient way to do this. The idea that an useful amount of power could come from turbines attached to house hold rain spouts is laughable.

I'm sure there will be those that will have them installed as a novelty. Just like geo thermal.

But that's all it will ever be, a novelty.

WWWTT

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Tim also mistakenly suggested that such pipes increase energy requirements.

It is not a mistake. A well designed system will factor in the effect of gravity and any attempt to siphon this gravitational energy off for electricity will increase the amount of energy that needs to be put into pumps in order to maintain the water pressure. That said, it appears Oregon, with mountain reservoirs, has a surplus of gravitational energy which can be tapped without negative effects, however, such geography is not available in most places.

There is certainly no way to create a net production of electricity from a water tower, unless one uses solar/wind power to fill the tower when the sun shines/wind blows (i.e. use power that would otherwise be wasted because no one needs its it at the time it is available). However, I suspect it would be very difficult to synchronize the availability of power with water demands without building a much larger tower.

Edited by TimG

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I imagine they will expand this system once the test phases proves successfu

why put a bunch of wee turbines in a reservoir to stroge area at all, it defeats any sensible approach to econimies of scale.

There is nothing that needs testing in conventional turbines in a conventional setting for generating conventional power.

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There is certainly no way to create a net production of electricity from a water tower, unless one uses solar/wind power to fill the tower when the sun shines/wind blows (i.e. use power that would otherwise be wasted because no one needs its it at the time it is available). However, I suspect it would be very difficult to synchronize the availability of power with water demands without building a much larger tower.

Water towers would have to be unfeasibly gigantic to be able to smooth over long enough periods for this to work. However, pumping water uphill to store energy when a surplus is available is done at a number of hydro dams (which can store many orders of magnitude more energy than water towers). This is the only currently feasible method for storing surplus energy from the grid in quantities that can make any real impact.

Edited by Bonam

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why put a bunch of wee turbines in a reservoir to stroge area at all, it defeats any sensible approach to econimies of scale.

There is nothing that needs testing in conventional turbines in a conventional setting for generating conventional power.

What needs testing is how a 24 7 source of power, heretofore untapped, can be tapped. If one short piece of pipe can supply the equivelant of 150 homes, with no significant effect on supply flow, then they may be onto something.

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Water towers would have to be unfeasibly gigantic to be able to smooth over long enough periods for this to work.

That is what I suspect as well but many people don't seem to understand that many "technically feasible" ideas are not "economically useful" ideas. Edited by TimG

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There is certainly no way to create a net production of electricity from a water tower, unless one uses solar/wind power to fill the tower when the sun shines/wind blows (i.e. use power that would otherwise be wasted because no one needs its it at the time it is available). However, I suspect it would be very difficult to synchronize the availability of power with water demands without building a much larger tower.

There is no need to achieve net positive electricity production on water towers since the pumps are already required to fill the towers regardless. Adding turbines to the down flow do not increase energy costs for pumping nor do they reduce the ability of towers to provide pressure for peak demand. The turbines simply add electricity generation capacity, thus reducing the overall electricity demand of the tower itself.

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There is no need to achieve net positive electricity production on water towers since the pumps are already required to fill the towers regardless.

The water system is designed to work with the gravitational energy stored by pumping the water into the towers. If you take some of that energy away the system will no longer work as designed. There is no such thing as a "free lunch". There is no way such as system could provide a net benefit.

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The water system is designed to work with the gravitational energy stored by pumping the water into the towers. If you take some of that energy away the system will no longer work as designed. There is no such thing as a "free lunch". There is no way such as system could provide a net benefit.

No, the system does not depend on the speed of water falling down towers. Unless the turbine was able to completely stop tower water flow, they have no impact on the towers benefit to the water system. The tower simply adds pressure and provides volume for peak demand.

Turbines installed in the actual mains themselves do provide resistance and thus lower the overall water flow. These turbines are only useful if excess pressure exists. Areas where reservoirs are at a higher elevation than municipalities, which is common, can benefit from that situation as well.

Edited by Mighty AC

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No, the system does not depend on the speed of water falling down towers.

The water system depends on the potential energy stored in the towers. That potential energy is used to pressurize the pipes. Letting the water simply drop out of the tower would be a waste of valuable energy. Using the energy to spin turbines would also be a waste of valuable energy. Edited by TimG

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