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How much electricity would I use...

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coffee
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Re: How much electricity would I use...

#41 Post by coffee » February 7th, 2011, 10:13 am

Latest post of the previous page:

Thank you everyone.

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Dave B
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Re: How much electricity would I use...

#42 Post by Dave B » February 7th, 2011, 10:44 am

Just one more thing that some may not realise: all the electricity and all the gas you use heats the planet up. It is (essentially) all converted to heat that heats up the room, heats up the house and heats up the planet.
I was going to ask, "And thence the Universe, Alan?" but then I remembered some theory about everything ending up the same (bloody cold) temperature one day in the very far future. It doesn't heat the Universe as a whole, just spreads the energy out a bit more.
"Look forward; yesterday was a lesson, if you did not learn from it you wasted it."
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Alan H
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Re: How much electricity would I use...

#43 Post by Alan H » February 7th, 2011, 11:48 am

Dave B wrote:
Alan H wrote:The resistor in series with a neon for 230 V would be more like 270k. Also, the neon voltage would be around 80 V, so the voltage across the resistor would be (230 - 80) = 150 V. This gives an rms current of 150/270000 = 0.56 mA. The resistor current is obviously the neon current as well, so the power taken from the mains is 230 * 0.55 mA = 0.13 W.

8760 hours per year gives 1.14 kWh, so at 13p per kWh gives about 15p per annum.

Does that look right?
270k not 47k? Ah, there goes my memory again! Well, only ten times out on the current . . . .

I'll keep quiet in future. :redface:
I've not checked, but I sincerely hope that my mains neon screwdriver (where you test if a terminal is live by providing the circuit to ground to light the neon) has a fairly large value resistor - I think 470k or thereabouts. :D
Alan Henness

There are three fundamental questions for anyone advocating Brexit:

1. What, precisely, are the significant and tangible benefits of leaving the EU?
2. What damage to the UK and its citizens is an acceptable price to pay for those benefits?
3. Which ruling of the ECJ is most persuasive of the need to leave its jurisdiction?

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Dave B
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Re: How much electricity would I use...

#44 Post by Dave B » February 7th, 2011, 5:25 pm

Alan H wrote:
Dave B wrote:
Alan H wrote:The resistor in series with a neon for 230 V would be more like 270k. Also, the neon voltage would be around 80 V, so the voltage across the resistor would be (230 - 80) = 150 V. This gives an rms current of 150/270000 = 0.56 mA. The resistor current is obviously the neon current as well, so the power taken from the mains is 230 * 0.55 mA = 0.13 W.

8760 hours per year gives 1.14 kWh, so at 13p per kWh gives about 15p per annum.

Does that look right?
270k not 47k? Ah, there goes my memory again! Well, only ten times out on the current . . . .

I'll keep quiet in future. :redface:
I've not checked, but I sincerely hope that my mains neon screwdriver (where you test if a terminal is live by providing the circuit to ground to light the neon) has a fairly large value resistor - I think 470k or thereabouts. :D
Ah2, still only a factor of ten out then, but somewhere else. :redface:

Actually what is the most embarrassing is forgetting to factor in the Vdrop over the neon itself. In my defence I have to say that I have done no electrical theory work since 2004. Oh, yes I have, I wired up some LEDs to a 12v car system - so I should have remembered the method for this! Ooops - there goes another thousand brain cells.
"Look forward; yesterday was a lesson, if you did not learn from it you wasted it."
Me, 2015

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Alan H
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Re: How much electricity would I use...

#45 Post by Alan H » February 7th, 2011, 6:36 pm

Dave B wrote:Actually what is the most embarrassing is forgetting to factor in the Vdrop over the neon itself. In my defence I have to say that I have done no electrical theory work since 2004. Oh, yes I have, I wired up some LEDs to a 12v car system - so I should have remembered the method for this! Ooops - there goes another thousand brain cells.
You did say you did it in your head!
Alan Henness

There are three fundamental questions for anyone advocating Brexit:

1. What, precisely, are the significant and tangible benefits of leaving the EU?
2. What damage to the UK and its citizens is an acceptable price to pay for those benefits?
3. Which ruling of the ECJ is most persuasive of the need to leave its jurisdiction?

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Dave B
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Re: How much electricity would I use...

#46 Post by Dave B » February 7th, 2011, 7:03 pm

Alan H wrote:
Dave B wrote:Actually what is the most embarrassing is forgetting to factor in the Vdrop over the neon itself. In my defence I have to say that I have done no electrical theory work since 2004. Oh, yes I have, I wired up some LEDs to a 12v car system - so I should have remembered the method for this! Ooops - there goes another thousand brain cells.
You did say you did it in your head!
The first time yes, but this last time I did it on the screen using a calculator.

Got the maths right, just got the theory wrong . . . Can end up with a nasty result that way!
"Look forward; yesterday was a lesson, if you did not learn from it you wasted it."
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robzed
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Re: How much electricity would I use...

#47 Post by robzed » February 7th, 2011, 8:52 pm

Alan H wrote: But it's not that simple! The heat generated by equipment on standby is dissipated into the room (so, if a device takes, say, 5 W, on standby, all of that 5 W will be dissipated into the room. If you have a thermostat on your central heating, it will switch on your CH less because of that 5 W and you will use less gas. However, the amount is tiny.
Hey, not accurate!!!!
  • I agree about energy for a normal house in the winter. But in the summer you ARE wasting energy. (OK, you did point this out in the compact fluorescent light case)
  • And with Gas central heating you will be paying less MONEY (Gas costs less per unit of energy than electricity - for me at least)
  • Also we could argue that it's safer to turn things off (I have no proof of this.)
Alan H wrote: BTW, moving over to compact fluorescents light bulbs has the opposite effect: if you replace a 60 W incandescent bulb with an 11 W CFL, your Ch has to compensate for this by using 49 W more gas to keep the room at the same temperature.
In terms of cost, I notice 3 Philips 14W CFLs are 30p. This is approximately the same as incandescent bulbs. But, in my experience and in the quoted figures, they have a much longer life. Therefore, CFLs are cheaper for purchase and cheaper to run. Therefore for MONEY you are better off with CFLs, I bet. And, in terms of money for heating bills, with gas central heating the 49W is cheaper :)
Alan H wrote: Just one more thing that some may not realise: all the electricity and all the gas you use heats the planet up. It is (essentially) all converted to heat that heats up the room, heats up the house and heats up the planet.
Oh no it's not!!! :)
Maybe most of it is, but the wind power and other sustainable energy sources generating electricity aren't. (Agreed they are small against coal/oil burning power stations.) Nuclear is slight - but only short term, long term I bet it's the same amount of energy released because that material is going to decay anyway - we are just 'helping it along' :) (Whether using electricity over gas/oil for heating is worth it to reduce heating up the planet would mean looking at extraction/processing/generation and transmission).

Additionally ALL gas burning releases CO2, which is not offset unless it's some form bio gas (if such a thing exists as mass-produced fuel yet).

This might mean you can either generate less CO2 but pay more money by using electricity, which would be ironic. (For some definition of ironic).

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Dave B
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Re: How much electricity would I use...

#48 Post by Dave B » February 7th, 2011, 9:20 pm

Since there is quite a large difference between the cost, per unit, of gas and electricity in my tariff might the extra gas usage needed to replace the heat lost by using low-energy lamps be in one's favour in pennies per hour?

Hmm, just occurred to me that a fair amount of the heat derived from gas heating goes straight out of the flue whilst, in terms of the house, all the electrical heat is contained! So, for 100W in the house how much goes outa the flue one wonders.

Perhaps the picture is rather complex - have to check on the efficiencies of gas heating!
"Look forward; yesterday was a lesson, if you did not learn from it you wasted it."
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Alan C.
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Re: How much electricity would I use...

#49 Post by Alan C. » February 7th, 2011, 11:53 pm

Dave B (have to use your full moniker now we have a DavidF)
Perhaps the picture is rather complex - have to check on the efficiencies of gas heating!
No gas here except in bottles, £35 for 19 Kilo propane, yet they "flare off" god knows how many tons? At the oil terminal 7 days a week 24 hours a day, waste or what?
Abstinence Makes the Church Grow Fondlers.

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Alan H
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Re: How much electricity would I use...

#50 Post by Alan H » February 8th, 2011, 1:33 am

robzed wrote:
Alan H wrote: But it's not that simple! The heat generated by equipment on standby is dissipated into the room (so, if a device takes, say, 5 W, on standby, all of that 5 W will be dissipated into the room. If you have a thermostat on your central heating, it will switch on your CH less because of that 5 W and you will use less gas. However, the amount is tiny.
Hey, not accurate!!!!
  • I agree about energy for a normal house in the winter. But in the summer you ARE wasting energy. (OK, you did point this out in the compact fluorescent light case)
That's really why I said "If you have a thermostat on your central heating, it will switch on your CH less". Perhaps I should have been more explicit about what happens when you don't have your CH on.
In terms of cost, I notice 3 Philips 14W CFLs are 30p.
Good grief!
Alan H wrote: Just one more thing that some may not realise: all the electricity and all the gas you use heats the planet up. It is (essentially) all converted to heat that heats up the room, heats up the house and heats up the planet.
Oh no it's not!!! :)
Maybe most of it is, but the wind power and other sustainable energy sources generating electricity aren't. (Agreed they are small against coal/oil burning power stations.) Nuclear is slight - but only short term, long term I bet it's the same amount of energy released because that material is going to decay anyway - we are just 'helping it along' :) (Whether using electricity over gas/oil for heating is worth it to reduce heating up the planet would mean looking at extraction/processing/generation and transmission).
I'm saying that (virtually) all power you use in your home is dissipated as heat, thereby heating the planet, regardless of what generates that power. Generation methods add to that, depending on their source. What I don't know is whether the vast amounts of energy we use is in any way comparable to the heating effect of greenhouse gasses - any ideas?
Additionally ALL gas burning releases CO2, which is not offset unless it's some form bio gas (if such a thing exists as mass-produced fuel yet).
Yes, I believe there are many schemes, but I don't know what size.
Alan Henness

There are three fundamental questions for anyone advocating Brexit:

1. What, precisely, are the significant and tangible benefits of leaving the EU?
2. What damage to the UK and its citizens is an acceptable price to pay for those benefits?
3. Which ruling of the ECJ is most persuasive of the need to leave its jurisdiction?

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Griblet
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Re: How much electricity would I use...

#51 Post by Griblet » February 8th, 2011, 7:47 pm

Alan H wrote:What I don't know is whether the vast amounts of energy we use is in any way comparable to the heating effect of greenhouse gasses - any ideas?
This is not a full answer, but I suppose all heat generated is radiated away into space pretty soon, whereas the greenhouse gases persist for longer and trap heat in for a long time.
A man without religion is like a fish without a bicycle.

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robzed
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Re: How much electricity would I use...

#52 Post by robzed » February 9th, 2011, 6:48 am

Hi Alan,

Obviously I was being argumentative just because it's more interesting.
Alan H wrote:
robzed wrote: In terms of cost, I notice 3 Philips 14W CFLs are 30p.
Good grief!
This made me laugh :-)
Alan H wrote: I'm saying that (virtually) all power you use in your home is dissipated as heat, thereby heating the planet, regardless of what generates that power.
For wind energy ... that wind is going to generate heat on the planet at some point ANYWAY, so I figure we might as well capture it and relocate the heat., if you see what I mean. (Additionally no CO2).

Or have I missed something?

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robzed
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Re: How much electricity would I use...

#53 Post by robzed » February 9th, 2011, 7:10 am

Griblet wrote:
Alan H wrote:What I don't know is whether the vast amounts of energy we use is in any way comparable to the heating effect of greenhouse gasses - any ideas?
This is not a full answer, but I suppose all heat generated is radiated away into space pretty soon, whereas the greenhouse gases persist for longer and trap heat in for a long time.

According to Wikipedia (http://en.wikipedia.org/wiki/World_ener ... onsumption)

We use:
"474 exajoules (474×10^18 J) with 80 to 90 percent derived from the combustion of fossil fuels. This is equivalent to an average power consumption rate of 15 terawatts (1.504×10^13 W)."

We get from the Sun:
"For the whole Earth, with a cross section of 127,400,000 km2, the total energy rate is 174 petawatts (1.740×10^17 W), plus or minus 3.5%. This value is the total rate of solar energy received by the planet; about half, 89 PW, reaches the Earth's surface."

Fossil fuels are made up of stored sunlight (effectively). Nuclear (6%) and Geothermal (0.2%) are not sunlight based.

So I guess that means the heating effect due to human fossil fuel, nuclear and geothermal would be (approximately) less than = 15 terawatts / 174 petawatts = 1.50 / 1.74 * 10^4 = 0.0000862 = 0.00862%.

That is to say, human heating is 0.00862% of the energy we receive from the sun.

Is this significant? According to wikipedia (http://en.wikipedia.org/wiki/Solar_variation) Solar Variation due to the 11 year cycle:
"Total solar output is now measured to vary (over the last three 11-year sunspot cycles) by approximately 0.1% [2][3][4] or about 1.3 W/m² peak-to-trough during the 11 year sunspot cycle. "

Probably not.

OTHER FACTORS
What about energy output from volanoes and other geothermal heat that reaches the surface? I couldn't figures quickly.

Energy lost into space - this is an simple but interesting page: http://okfirst.mesonet.org/train/meteor ... udget.html

Also we should consider the heating effect due to extra greenhouse gases, but I bet it's much more significant than energy radiated by humans into the atmosphere :)

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Re: How much electricity would I use...

#54 Post by Dave B » February 9th, 2011, 3:34 pm

Just goes to show that it an extremely complex system that cannot really be simplified and presented in a convincing way that does not beg questions, but can probably be manipulated to say almost anything you want, especially by selective omission of data.
"Look forward; yesterday was a lesson, if you did not learn from it you wasted it."
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Alan H
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Re: How much electricity would I use...

#55 Post by Alan H » February 9th, 2011, 6:47 pm

robzed wrote:That is to say, human heating is 0.00862% of the energy we receive from the sun.
Fascinating! I suspected that what man produces would be tiny in comparison, but hadn't looked at the numbers. If you think about it, all we manage to do is warm our buildings a bit; the sun warns everything around us - how much difference does a patio heater make outside of a very small area?
Alan Henness

There are three fundamental questions for anyone advocating Brexit:

1. What, precisely, are the significant and tangible benefits of leaving the EU?
2. What damage to the UK and its citizens is an acceptable price to pay for those benefits?
3. Which ruling of the ECJ is most persuasive of the need to leave its jurisdiction?

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robzed
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Re: How much electricity would I use...

#56 Post by robzed » February 9th, 2011, 7:59 pm

Alan H wrote:
robzed wrote:That is to say, human heating is 0.00862% of the energy we receive from the sun.
Fascinating! I suspected that what man produces would be tiny in comparison, but hadn't looked at the numbers. If you think about it, all we manage to do is warm our buildings a bit; the sun warns everything around us - how much difference does a patio heater make outside of a very small area?
I think the thing with humans is we have, until recently, thought that we have no effect globally. But CO2 does this amplification thing that, coupled with deforestation, means trapped solar heat.

Longer term (several thousand years) if man doesn't cut down all the trees, then a recent study has shown that plants and trees will do well from the higher CO2 atmosphere. (There was a good link to an article somewhere if you want to see it)

Of course millions will have died by then and millions more been displaced.

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Alan C.
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Re: How much electricity would I use...

#57 Post by Alan C. » February 9th, 2011, 8:12 pm

robzed
if man doesn't cut down all the trees,
I'm not even going to try and get my head around the main topic of this thread, but I do think (IMHO) deforestation is causing much more damage to the planet than anything else we humans are doing.
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robzed
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Re: How much electricity would I use...

#58 Post by robzed » February 9th, 2011, 8:30 pm

Alan C. wrote:
robzed
if man doesn't cut down all the trees,
I'm not even going to try and get my head around the main topic of this thread, but I do think (IMHO) deforestation is causing much more damage to the planet than anything else we humans are doing.
I think we are off-topics, strictly speaking.

This is what I was referring to:
http://news.mongabay.com/2005/1210-fao.html

There are a few bad things that we've done for a relatively short amount of time (a few thousand years). E.g. it's got to be above 95% of the UK landscape that is man-made (e.g. farms - what people ironically consider natural - as if 'countryside' was anything but man made). Tarmac, CO2 and taking all the fish out the sea, and killing a few million species.

But apart from that, we are pretty benign - aren't we?

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Re: How much electricity would I use...

#59 Post by coffee » February 11th, 2011, 10:59 am

Dave B

I have read your message about the gadget. I would like to thank you but I don't really need it. Thank you very much for your offer.

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