Power from Tap

Dampsquid

How much power could you generate from the water pressure from the water tap in your house. If you hooked it up to a mini turbine, i'm sure you could get a decent amount of energy out of it.

Dave!

Probably, but when water charges come in you'll be fooked.

Thrill

Couldn't tell you, but if there was one in every household then it wouldn't be too long before we would have water shortages, and if you have a water meter in your house it probably wouldn't be worth it.

KamiKazi

you could get power from it, but your guaranteed to use more energy on said waterpump

so you see the flaw in ur plan?

faceman

What a stupid idea. Is there no electricity in your gaff or something? I wont even mention the waste of water!

Mossy Monk

i dont think its an idea more of a querey about how much energy would be generated

ChippingSodbury

Well Mossy,
To be a nerd about it, you would use Bernoulli's equation to work out the energy balance. Assuming you're not looking at Lab conditions, you would assume that you have inviscid flow (a fluid flow with no loss due to friction) and all other ideal conditions. Then work out the difference in the energy stored in the fluid at Point 1 (start) and Point 2 (end). The amount of energy you could usefully then extract would be less than that (due to friction, losses etc.) but this would give you a good idea. Bernoulli's equation basically says:
Pressure + Kinetic Energy + Potential Energy = Constant

So in your case:
Pressure1 + Kinetic Energy1 + Potential Energy1 = Pressure2 + Kinetic Energy2 + Potential Energy2 + Energy Taken From Turbine

If you assume that the Kinetic Energy in both condition 1 and 2 is 0 or negligible (because at pos1 the fluid isn't moving and pos2 it has also stopped therefore velocity=0 and no energy due to movement). If you assume your pressure after turbine = atmospheric i.e. 0 Bar gauge, then this term also disappears.

You equation will now be:

Pressure1 + Potential Energy1 = Potential Energy2 + Energy Taken From Turbine

or Energy Taken From Turbine = Pressure1 + Potential Energy1 - Potential Energy2

The difference in Potential Energy between the two states is really just the difference in height X density X gravity

So:
Energy Taken From Turbine = Pressure1 + density X 9.81 X (Height1 - Height2)

Pop your values in using SI units and you should get a sensible answer!!

The_Minister

KamiKazi wrote:

you could get power from it, but your guaranteed to use more energy on said waterpump

Unless the pressure came from a high-altitude resevoir.

randylonghorn

ChippingSodbury wrote:

...

RESPECT!

/ head explodes with high level of kinetic energy

Mossy Monk

ChippingSodbury wrote:

Well Mossy,
To be a nerd about it, you would use Bernoulli's equation to work out the energy balance. Assuming you're not looking at Lab conditions, you would assume that you have inviscid flow (a fluid flow with no loss due to friction) and all other ideal conditions. Then work out the difference in the energy stored in the fluid at Point 1 (start) and Point 2 (end). The amount of energy you could usefully then extract would be less than that (due to friction, losses etc.) but this would give you a good idea. Bernoulli's equation basically says:
Pressure + Kinetic Energy + Potential Energy = Constant

So in your case:
Pressure1 + Kinetic Energy1 + Potential Energy1 = Pressure2 + Kinetic Energy2 + Potential Energy2 + Energy Taken From Turbine

If you assume that the Kinetic Energy in both condition 1 and 2 is 0 or negligible (because at pos1 the fluid isn't moving and pos2 it has also stopped therefore velocity=0 and no energy due to movement). If you assume your pressure after turbine = atmospheric i.e. 0 Bar gauge, then this term also disappears.

You equation will now be:

Pressure1 + Potential Energy1 = Potential Energy2 + Energy Taken From Turbine

or Energy Taken From Turbine = Pressure1 + Potential Energy1 - Potential Energy2

The difference in Potential Energy between the two states is really just the difference in height X density X gravity

So:
Energy Taken From Turbine = Pressure1 + density X 9.81 X (Height1 - Height2)

Pop your values in using SI units and you should get a sensible answer!!

i look forward to the translated to English version

kdouglas

<ridiculously pointless idea>

hmmm... could your perhaps attach a smal turbine to the water pipe where it leaves the reservoir tank in the attic so that everytime someone actually turns on a tap to use the water it passes through this on it's way and generates some electricity, probably only enough to power a lightbulb, but every little counts right? lol

or even attach a turbine to the outlet drains so that everytime water flows out of the house it generates more electricity?

</ridiculously pointless idea>

nice idea though, probably more efficient to stick a couple of small wind turbines on your roof though

pclancy

Wind turbine would be way better option obviously but its something someone must have thought about and tried.

Nice work ChippingSodbury well explained!

KamiKazi

afaik, it'd take a good bit of pressure to get a turbine to start rotating in the first place

OfflerCrocGod

Not enough to power a 40W bulb.

netwhizkid

Wouldn't it make more sense to suck the energy out of Eircom instead, their dial-up "communication" lines deliver something like 55V DC which could be used through an inverter to power stuff or directed through some gadget to charge a battery pack. You'd get better value out of it than the communications service they deliver.

Angeles

I don't think it would make much energy alone but the idea seems fairly sound imo for energy conserving.

Thoery - have all you taps hucked up to a mini turbine
Every time you need to use the water for say a drink or shower, you could be slowly powering a big battery

after a year or so's standerd use you'd have ALOT of excess power (thoery though)

Most households have there water tank in the attac, so pressure is not really a problem.

zuutroy

netwhizkid wrote:

Wouldn't it make more sense to suck the energy out of Eircom instead, their dial-up "communication" lines deliver something like 55V DC which could be used through an inverter to power stuff or directed through some gadget to charge a battery pack. You'd get better value out of it than the communications service they deliver.

you wouldnt be able to draw more than a few milliamps off it => <1W of power => fook all use.

zuutroy

Angeles wrote:

Every time you need to use the water for say a drink or shower, you could be slowly powering a big battery

Only problem being it would take about 1 minute to fill your glass because the turbine is taking all the pressure out of the water

Rb

Science?On After Hours?Wtf?

BaZmO*

You'd be probably better off attaching a mini turbine to your micky. That way you'd be able to power a little light bulb placed on your head for the next bright idea that you come up with.

robinph

faceman wrote:

I wont even mention the waste of water!

I've never been able to get my head around this water shortage thing. Unless it is all evaporating off into space then there is never going to be a water shortage on the planet, it might not rain back down in exactly the place that we'd like it to all the time but it doesn't disappear.

nesf

I had a reply last night but the internet wouldn't leave me post it.

Essentially you can't just use Bernoulli's Laws and assuming no kinetic energy in the water is incorrect.

Actually, just look it up on wiki, it has a decent explanation of turbines and how to calculate the max power output and all that stuff.

Blowfish

robinph wrote:

I've never been able to get my head around this water shortage thing. Unless it is all evaporating off into space then there is never going to be a water shortage on the planet, it might not rain back down in exactly the place that we'd like it to all the time but it doesn't disappear.

The water that comes through taps is treated. Its not a shortage of water, but a shortage of treated water that is the problem.

Tar.Aldarion

You would get crap all power from it.

faceman

robinph wrote:

I've never been able to get my head around this water shortage thing. Unless it is all evaporating off into space then there is never going to be a water shortage on the planet, it might not rain back down in exactly the place that we'd like it to all the time but it doesn't disappear.

:rolleyes:

Dundhoone

The nasty water conservation engineer would come to your house and issue you with a nice letter telling you not to waste water or else.

There is a nice law on water wastage from 1854 that he can slap you about the face with.:D

mwrf

BaZmO* wrote:

You'd be probably better off attaching a mini turbine to your micky. That way you'd be able to power a little light bulb placed on your head for the next bright idea that you come up with.

A+++

andrew

what'd happen if the corpo placed turbines on all the high pressure mains in dublin? i'd say you could get a usable amount of electricity, no?

BaZmO*

andrew wrote:

what'd happen if the corpo placed turbines on all the high pressure mains in dublin? i'd say you could get a usable amount of electricity, no?

Ya what?

What exactly do you think makes these high pressure mains become high pressure mains in the first place?

Dutchology

BaZmO* wrote:

You'd be probably better off attaching a mini turbine to your micky. That way you'd be able to power a little light bulb placed on your head for the next bright idea that you come up with.

ROFL, you've brightened up my day

Hal1

Reuse the same water for your generator thing which you described. Say you got a large water drum that held 20ltrs of water, that might work.

Dunno tbh.

Dundhoone

andrew wrote:

what'd happen if the corpo placed turbines on all the high pressure mains in dublin? i'd say you could get a usable amount of electricity, no?

A lot of those high pressure mains are high pressure because a pump is used to increase the pressure.

Installing a turbine would take pressure/energy from the water .

You'd have houses without water all over dublin if you did it in the morning.

It only makes sense where you have a water source at a high level in the first place, say a mountain stream - where the pressure would have to be reduced anyway before reaching the consumer.

ChippingSodbury

Dundhoone,
I'm disappointed with you: there at least 4 or 5 ways listed at http://www.lhup.edu/~dsimanek/museum/unwork.htm to get the energy out for free....