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as I stumbled around semi-concious this morning...
Posted: Sun May 06, 2007 9:47 pm
by colhut
I was wondering as I boiled the kettle on the hob...
Which has the lowest environmental impact..
boiling the kettler on the gas hob,
boiling an electric kettle,
or heating up a mug of water in the microwave.
anyone who dares to sugest that I should do without my caffiene injection, read my tag line !

Posted: Sun May 06, 2007 10:01 pm
by Andy Hamilton
obviously it depends on how much water you put in the kettle. Boiling on the gas stove uses less power than an electric kettle but it is nonrenewable and if you get your electricity from a renewable source then that would be better.
There is a new kettle out soonish that claims to boil water in a matter of seconds.
Not totally sure about the microwave and it would depend on what watt but by far the most environmentally friendly way would be to use a solar oven and as I have read Nev suggesting (in Grass Roots magazine), decant into a thermos.
Posted: Sun May 06, 2007 10:22 pm
by paddy
Andy Hamilton wrote:obviously it depends on how much water you put in the kettle. Boiling on the gas stove uses less power than an electric kettle but it is nonrenewable and if you get your electricity from a renewable source then that would be better.
There is a new kettle out soonish that claims to boil water in a matter of seconds.
Not totally sure about the microwave and it would depend on what watt but by far the most environmentally friendly way would be to use a solar oven and as I have read Nev suggesting (in Grass Roots magazine), decant into a thermos.
Sorry Andy you are wrong!!!!
Heating a kettle by placing a gas burner underneath it is hugely inefficient as most of the heat just goes into the atmosphere and not the water, and all the expence and energy used to obtain the gas and pump it to your cooker is also a waste
Heating water by immersing a heater into the water is very efficient but of course that electricity has been generated hundreds of miles away and a lot of the electricity has been wasted traveling along the power lines to the kettle.
A solid fuel ( wood ) range or stove to boil the kettle would be maybe not as efficient as an electric kettle but be the best on enviromental grounds
The microwave i have no idea of.

Posted: Sun May 06, 2007 10:58 pm
by Cornelian
A microwave can take AGES to boil water. I tried it once and never again. LOL
A billy can over a bed of hot coals, though, there's a rapid way to boil a cup of tea. :) Wood fires are not entirely environmentally friendly though, depending on what they pump into the atmosphere (depending on how efficient they are and what kind of fuel you burn).
Generally I just use precisely the amount of water I need for a cup of tea in an electric kettle and hope that I can trust my electricity company when it tells me it uses power from a renewable source (well it does, as our power here is largely hyrdo-electric).
Posted: Sun May 06, 2007 11:17 pm
by paddy
Cornelian wrote:A microwave can take AGES to boil water. I tried it once and never again. LOL
A billy can over a bed of hot coals, though, there's a rapid way to boil a cup of tea. :) Wood fires are not entirely environmentally friendly though, depending on what they pump into the atmosphere (depending on how efficient they are and what kind of fuel you burn).
Generally I just use precisely the amount of water I need for a cup of tea in an electric kettle and hope that I can trust my electricity company when it tells me it uses power from a renewable source (well it does, as our power here is largely hyrdo-electric).
I remember watching an Archelogical dig on the tele one night and they showed how our ancestors would have cooked and boiled water quickly, and that was by taking hot stones out of the fire that was cooking/boiling our water/food and dropping them into the pot/kettle......cooked/boiled twice as fast.
Posted: Mon May 07, 2007 12:00 am
by Wombat
Cornelian wrote:
A billy can over a bed of hot coals, though, there's a rapid way to boil a cup of tea. :) Wood fires are not entirely environmentally friendly though, depending on what they pump into the atmosphere (depending on how efficient they are and what kind of fuel you burn).
Ah yes, but they are carbon neutral.
The "volcano" style billy where you stuff leaves and twigs up the centre and water in a jacket around the outside would be more efficent still. I have got one.....just need to use it!
You still need a back up for the solar - even here in the land of Aus it rains occasionallly

, plus the downside of the solar one is that it is a bit slow. If you need your coffee NOW (

) then I would go with the volcano billy!
Nev
Posted: Mon May 07, 2007 9:18 am
by Clara
volcano billy = kelly kettle
I´ve got one and it´s great, especially when you´re out working and don´t want to go back indoors for a cuppa.
I don´t know about the physics of it but a solar engineer once told me that using electricity (however generated) to heat anything was ridiculous as it was taking the purest form of energy (electricity) and returning it to the most base form (heat). I guess he was talking about the effort required to make electicity in the first place
Clara x.
Posted: Mon May 07, 2007 9:47 am
by Jack
Gidday
The electric kettle or jug would definately lose out as the amount of wastage in transmission line is really huge but never talked about by any of these greenie types.
The best, and fastest by far would be a copper thermette.
http://www.thermette.com/
About 40 years ago I cam home from a fencing contract and our power went off right on lunch time. I told my mother I would boil the thermette and she said she would use the primus kerosene cooker. I went outside, scooped up a handful of chips from the wood heap and lit the thermette filled with cold water out of the garden tap. My mother thought she could beat me and filled the jug with hot water out the tap and used the kerosene cooker and I had the teapot fill with boiling water first.
These things are an ancient Kiwi invention, but the Aussies will probably claim it even though we had them whilst they were still using a bill on a stick.
Re: as I stumbled around semi-concious this morning...
Posted: Mon May 07, 2007 10:39 am
by Annpan
colhut wrote:
Which has the lowest environmental impact..
boiling the kettler on the gas hob,
boiling an electric kettle,
or heating up a mug of water in the microwave.
Going back to the original question... the electric kettle must to be the best.
But surely the best of all would be to put your kettle on your woodburner that you also get heat and hot water (the tap type) from, you wouldn't use much more more fuel than just keeping the fire burning anyway.

Posted: Mon May 07, 2007 12:12 pm
by hamster
I think the electric kettle is the most efficient as well, as it heats it up quickest and with least waste of heat energy, and its efficiency can be increased even further by use of microgeneration, renewable resources etc. Heating it on the stove wastes a lot of heat energy, but in winter you can
theoretically use this to help heat the room, though a nice big stew simmering away for 5 hours is probably a better way to do this.
volcano billy = kelly kettle
I always called them a storm kettle. Dunno why, cos they fall over at the merest provocation!
I want a cup of tea now!
Posted: Mon May 07, 2007 1:02 pm
by Wombat
There is also an Asian device used in a similar way called variably a firepot, hot pot, steam boat, volcano etc. You put some heat beads or whatever down the funnel, hot stock in the pot and then use the boiling stock to cook little bits of meat, veggies, tofu etc. It is a very sociable way to eat. Then at the end you have the stock with all of the cooking flavours in it as a soup.
I think that the principle was invented in China rather than Aus or NZ, Jack.
Nev
http://www.fantes.com/mongolian_hot_pot.htm#pot
Posted: Mon May 07, 2007 7:47 pm
by colhut
Excellent, lots of interestnig points. The solar oven would be far too slow, however I am experimenting with one (2 cardboard boxes a sheet of glass and no reflectors got a clear jam jar of water up to 54C two weeks ago, so I am suffuciently pleased to add more bits to it).
Back to the question in hand though I really don't know how to weigh it all up. Gas is non renewable, but then if the electricity that drives either the kettle or microwave is also generaeted from a fossil fuel then gas must come out on top. The kettle/microwave is interesting, the generation/transmission losses being cancelled out it comes donw to which most effieciently imparts energy into the water (again I don't know
Posted: Mon May 07, 2007 8:00 pm
by Muddypause
Well I think the calculation is more complicated. An electric kettle element is an efficient way to heat water, with little lost heat. But remember that most of that electricity started off as gas in the first place, which was inefficiently burnt to produce steam, which then inefficiently drove a turbine connected to a generator which inefficiently produced electricity. Some of it started off as coal, which is even more inefficient to convert into electricity, especially when you factor in the extraction process.
Posted: Mon May 07, 2007 8:15 pm
by paddy
Muddypause wrote:Well I think the calculation is more complicated. An electric kettle element is an efficient way to heat water, with little lost heat. But remember that most of that electricity started off as gas in the first place, which was inefficiently burnt to produce steam, which then inefficiently drove a turbine connected to a generator which inefficiently produced electricity. Some of it started off as coal, which is even more inefficient to convert into electricity, especially when you factor in the extraction process.
Well that's inefficient

you forgot to tell us how to make electricity efficiently and hurry up cause i'm dying for a cuppa.
Posted: Mon May 07, 2007 9:33 pm
by ina
Wombat wrote:
The "volcano" style billy where you stuff leaves and twigs up the centre and water in a jacket around the outside would be more efficent still. I have got one.....just need to use it!
Same problem here...
I did use it a couple of times last summer - managed to make a cuppa on just a few sheets of newspaper. There were black bits floating around the atmosphere, though.

I do intend to have a bag of dry twiggy bits handy this year.