Naked Science Forum

General Science => General Science => Topic started by: Soni on 17/05/2011 12:43:24

Title: Which is more efficient: electric kettle, or gas stove kettle?
Post by: Soni on 17/05/2011 12:43:24
Which is more energy efficient - an electric kettle or a traditional gas stove kettle?

Thanks
Title: Electric kettle vs gas stove kettle?
Post by: CZARCAR on 17/05/2011 13:22:48
i have a plastic electric tkettle that worx fast & well.takes 6 min. @1kw to heat 1 qt. water from 50*f to a rolling boil & that ~100w 0r 350 btu or $.018 electric cost @ $.18/KWhr... it sits beside the gas stove which i cant measure the gas used so to compare.... plastic is touchable when water boils so heatloss aint much..........350 btu from propane would cost me $.013  @$3.30/gal LP but the metal container loses much more heat i think
Title: Electric kettle vs gas stove kettle?
Post by: syhprum on 17/05/2011 13:59:46
My electriciy not unsurprisingly costs me four times as much per Joule as my mains gas supply.
even allowing for only about 50% efficiency transferring the heat from the gas hob to the water it would only cost half as much.
Title: Electric kettle vs gas stove kettle?
Post by: imatfaal on 17/05/2011 14:01:10
Totally non-quantitatively: there is an absolute minimum amount of energy that is required by theory to heat a kettle of water, in the real world we will use much more than that.  But the extra energy used doesn't disappear (it can't) it goes to making noise, heating other stuff etc; the main loss in heating water is that the environment surrounding the water will get heated up as well.

When I heat a kettle on a stove I can feel the air around it, the stove itself and the body of the kettle getting very hot - ie energy that is not heating the water. Whereas in my electric kettle the only thing that gets very heated is the water (even the body of the kettle is handleable).  It would seem that to heat one lot of water the stove kettle heats much more of the immediate environment than the electric kettle.  the stove kettle is using much more excess energy over the bare minimum and is thus making a less efficient use of the energy provided.

How the energy to heat water gets to your house is another matter! The electricity has to come from somewhere as does the fuel for your stove.
Title: Electric kettle vs gas stove kettle?
Post by: CZARCAR on 17/05/2011 14:24:55
humidity & heatloss from open flame is ok for cold climate but not for warm climate especially if AC is running
Title: Electric kettle vs gas stove kettle?
Post by: Geezer on 17/05/2011 18:15:57
Actually, it's impossible to answer the question as it stands  [:D]

"Efficiency" could refer to all kinds of different measurements. This is a common problem with this sort of question, but everyone tends to take the bait and assume that everyone else is using the same measurement when, in fact, they are not.
Title: Electric kettle vs gas stove kettle?
Post by: CZARCAR on 18/05/2011 17:54:45
Actually, it's impossible to answer the question as it stands  [:D]

"Efficiency" could refer to all kinds of different measurements. This is a common problem with this sort of question, but everyone tends to take the bait and assume that everyone else is using the same measurement when, in fact, they are not.
not impossible 4me because i put some criteria down which i'd love critique= please read my posts & tell me where i failed, thanx
Title: Electric kettle vs gas stove kettle?
Post by: Geezer on 18/05/2011 19:24:01
Actually, it's impossible to answer the question as it stands  [:D]

"Efficiency" could refer to all kinds of different measurements. This is a common problem with this sort of question, but everyone tends to take the bait and assume that everyone else is using the same measurement when, in fact, they are not.
not impossible 4me because i put some criteria down which i'd love critique= please read my posts & tell me where i failed, thanx

What are you measureing the efficiency of? Some possible examples:

Energy cost
Capital cost utilization
Thermal energy equivalence
Chemical energy conversion (local)
Chemical energy conversion (total)
Evironmental impact
Distribution infrastructure
Carbon release
etc., etc.
Title: Electric kettle vs gas stove kettle?
Post by: CZARCAR on 18/05/2011 20:35:54
Actually, it's impossible to answer the question as it stands  [:D]

"Efficiency" could refer to all kinds of different measurements. This is a common problem with this sort of question, but everyone tends to take the bait and assume that everyone else is using the same measurement when, in fact, they are not.
not impossible 4me because i put some criteria down which i'd love critique= please read my posts & tell me where i failed, thanx

What are you measureing the efficiency of? Some possible examples:

Energy cost
Capital cost utilization
Thermal energy equivalence
Chemical energy conversion (local)
Chemical energy conversion (total)
Evironmental impact
Distribution infrastructure
Carbon release
etc., etc.
fine & dandy but can u simplify?
Title: Electric kettle vs gas stove kettle?
Post by: CliffordK on 18/05/2011 20:46:17
Might as well use a charcoal fired samovar.

100% renewable fuel.
No electricity.
No Gas.

Does it count that the Russians used Lead Solder to put them together?
Title: Electric kettle vs gas stove kettle?
Post by: imatfaal on 18/05/2011 21:22:58
Actually, it's impossible to answer the question as it stands  [:D]

"Efficiency" could refer to all kinds of different measurements. This is a common problem with this sort of question, but everyone tends to take the bait and assume that everyone else is using the same measurement when, in fact, they are not.
not impossible 4me because i put some criteria down which i'd love critique= please read my posts & tell me where i failed, thanx

What are you measureing the efficiency of? Some possible examples:

Energy cost
Capital cost utilization
Thermal energy equivalence
Chemical energy conversion (local)
Chemical energy conversion (total)
Evironmental impact
Distribution infrastructure
Carbon release
etc., etc.

Comparison of marginal energy usage (in joules) needed to boil a kettle of water.  Everything else you have listed is a meta-efficiency concerning an additional factor (economics, environmental concerns, practicality etc) . the fact that much more useful and real world alternatives exist (as you have listed) does not preclude the existence of simple (if practically useless) measure. 
Title: Electric kettle vs gas stove kettle?
Post by: Geezer on 18/05/2011 22:10:36
Actually, it's impossible to answer the question as it stands  [:D]

"Efficiency" could refer to all kinds of different measurements. This is a common problem with this sort of question, but everyone tends to take the bait and assume that everyone else is using the same measurement when, in fact, they are not.
not impossible 4me because i put some criteria down which i'd love critique= please read my posts & tell me where i failed, thanx

What are you measuring the efficiency of? Some possible examples:

Energy cost
Capital cost utilization
Thermal energy equivalence
Chemical energy conversion (local)
Chemical energy conversion (total)
Environmental impact
Distribution infrastructure
Carbon release
etc., etc.

Comparison of marginal energy usage (in joules) needed to boil a kettle of water.  Everything else you have listed is a meta-efficiency concerning an additional factor (economics, environmental concerns, practicality etc) . the fact that much more useful and real world alternatives exist (as you have listed) does not preclude the existence of simple (if practically useless) measure. 

Right! Could well be, but it's still an assumption.

Assuming that's what the OP meant, is that just the joules consumed at the point of energy consumption, or does it include the total joules consumed including production, distribution etc., etc.

My point is, that unless you define what resource you want to be efficient with, you can get some very different results.

e.g. - Is a bus more efficient than a car?
Title: Electric kettle vs gas stove kettle?
Post by: imatfaal on 18/05/2011 23:15:00
Right! Could well be, but it's still an assumption.

Assuming that's what the OP meant, is that just the joules consumed at the point of energy consumption, or does it include the total joules consumed including production, distribution etc., etc.
I did say marginal usage of energy in joules - that's the extra energy usage to boil one extra kettle on the stove vs the extra energy usage to boil in an electric kettle.
Quote
My point is, that unless you define what resource you want to be efficient with, you can get some very different results.
You mean I only imagined that the the OP asked
Quote
Which is more energy efficient...
[;D]

Quote
e.g. - Is a bus more efficient than a car?
Now that's difficult cos - there are so many more equally accepted measures, you haven't specified energy/cost/time efficient, whether it is from a global planinng or personal commuting perspective. 

I know what you mean and I tend to agree - but I think we have all got too used to politicians and the media telling us that questions cannot be answered  - its not that they cannot be answered, it's that the answer is very useful in a specific case but simultaneously absolutely worthless in general.  
Title: Electric kettle vs gas stove kettle?
Post by: Geezer on 19/05/2011 01:56:10
I could be even more obtuse and point out that electricity isn't really energy at all [;D]. It's merely a means of transmitting energy, just like the drive shafts on your car, only somewhat longer.
Title: Electric kettle vs gas stove kettle?
Post by: imatfaal on 19/05/2011 10:18:12
On a more serious note - before we derail the thread entirely, I would be interested to know the energy cost of provision of energy.  Again with marginal costs to avoid difficulties with infra-structure costs - how much energy is used to get electricity to my house (that I can use to boil a kettle) compared to getting gas to my house.  I guess this could be calculated in (joules available to me)/(total energy cost in joules); and I presume that this would closely follow the actual price per unit energy that I pay - but I really don't know that. 

In the USA I presume you would have a third commonly available energy source - heating oil, which whilst available in UK is very uncommon
Title: Electric kettle vs gas stove kettle?
Post by: Geezer on 19/05/2011 10:27:04
In the USA I presume you would have a third commonly available energy source - heating oil, which whilst available in UK is very uncommon

It has become a lot less commom in the US too!

We are not connected to a natural gas grid, but we have a liquid propane storage tank that supplies a lot of our space heating.

I calculated that I could generate my own electric power from gasoline for the same price that I was paying the utility company for electricity. That was a while ago, so things might have changed a bit, but, fundamentally, the main reason for buying electricity seems to be the convenience factor (until it goes off of course).
Title: Electric kettle vs gas stove kettle?
Post by: CliffordK on 19/05/2011 12:36:55
I calculated that I could generate my own electric power from gasoline for the same price that I was paying the utility company for electricity. That was a while ago, so things might have changed a bit, but, fundamentally, the main reason for buying electricity seems to be the convenience factor (until it goes off of course).

When did you make that calculation?  1960?

I've heard that it takes about 1/3 the cost to power an electric vehicle than a gas vehicle.  So I'm skeptical, although perhaps efficiency and delivery cost makes up some of the difference.

Laclede Gas, however, will sell you a Natural Gas backup generator system.  It sounds like a pretty sweet deal. 

Heating oil is loosing popularity.  However, here it is only used for home heating, and not for cooking.  It is essentially the same as Kerosene.  I believe you can purchase kerosene ovens in Europe.

http://en.wikipedia.org/wiki/AGA_cooker

There are some people who put a kettle on the oil stove to increase the humidity in the room.  One potentially could use that for tea water (in the winter).
Title: Electric kettle vs gas stove kettle?
Post by: CZARCAR on 19/05/2011 16:32:22
On a more serious note - before we derail the thread entirely, I would be interested to know the energy cost of provision of energy.  Again with marginal costs to avoid difficulties with infra-structure costs - how much energy is used to get electricity to my house (that I can use to boil a kettle) compared to getting gas to my house.  I guess this could be calculated in (joules available to me)/(total energy cost in joules); and I presume that this would closely follow the actual price per unit energy that I pay - but I really don't know that. 

In the USA I presume you would have a third commonly available energy source - heating oil, which whilst available in UK is very uncommon
Maine has 2 charges for the e bill. 1 for energy cost & 1 for transmission cost which is higher than the energy cost
Title: Electric kettle vs gas stove kettle?
Post by: Geezer on 19/05/2011 18:39:35

When did you make that calculation?  1960?


Wait a minute. You are right! That's not what I calculated.

What I did work out is that I could heat my home using gasoline for the same cost as heating it with electricity. That's quite a bit different.

It was a few years ago though, so I'm not sure it's still true.
Title: Electric kettle vs gas stove kettle?
Post by: CZARCAR on 19/05/2011 19:40:41

When did you make that calculation?  1960?


Wait a minute. You are right! That's not what I calculated.

What I did work out is that I could heat my home using gasoline for the same cost as heating it with electricity. That's quite a bit different.

It was a few years ago though, so I'm not sure it's still true.
new oil furnace maxes @ 85% efficiency- condensing gas @ 95%...indoor generator is tricky if not illegal & like an outdoor wood boiler?