As my kettle’s on the blink and I’ve resorted to using a saucepan over gas to boil water (which I quite like), I was just wondering which method uses the most energy to boil an equal amount of water?

Saucepan. Kettle is much more efficient.

Aggreed, but the energy used to produce the electricity in the first instance has to be more than the gas surely?? Now I’m no expert but just sort of makes sense to me. No doubt I’ll be proved wrong very shortly. lol

I’m sure you’re right real man. As a device it’s probably more efficient. Apparently ‘though a kettle uses the same amount of energy to boil one litre of water as it does to power a typical fridge for seven hours..

The same as carlos I was thinking along the lines of gas being a direct energy source whereas electricity is indirect, whith only a relatively small proportion derived from sustainable energy sources.

Almost all the energy input in a kettle goes to heating the water. A hell of a lot of the energy input for the saucepan goes anywhere but into the water – convection will draw a lot up the side of the pan.

It could be a fairly close run thing. Wikipedia reckons cooking on gas is about 30% efficient. It also says your average fossil power station is about 50% efficient. But you also have to take into account transmission losses – one of the power firms had an ad in the Economist the other week and the transmission losses were very large, I think in the order of 50% or so.

Microwave it.

really frown at it while your waiting.

Also bear in mind that kW for kW gas is about half to a third the cost of electricity.

Saucepan is more efficient (if you add salt and put the lid on)

Makes your tea taste sh1te, though.

tron – Member
Almost all the energy input in a kettle goes to heating the water. A hell of a lot of the energy input for the saucepan goes anywhere but into the water – convection will draw a lot up the side of the pan.

Very true.

You can put your hands pretty close to a kettle whilst it is boiling, but I would not like to put my hands as close as that to a pan whilst it is boiling on the hob!

The resulting cup of tea always tastes like saucepan. Eeeuuuurgh

here we go again (yes we did this one on the old forum)
there is a very easy(ish) way to calculate the efficiency of boiling water.
All electrical apparatus have an sticker on the bottom with the power consumption. This is the power they draw from the grid. We shall call it P. However to boil water you need energy (lets call this one E).
The energy is simply a power applied a certain amount of time t:
E = P*t. The unit of the enrgy is J.
If you want to increase the temperature of one cl of water from one °K (or °C) you need I cal or better said 4.18 J.

Now lets say you want to see which way is the more efficient. It’s easy. Take 6 mugs of water (all at the same temperature Ti and around 300 ml). Put 2 in the MWO, 2 in the pan on the hob and the last 2 in the kettle. Now turn them all on for one minute (t=60). Check the new temperature Tf that will be called: Tfm, Tfh, Tfk for the MWO, the hob, the kettle respectively.
You can calculate the real energy you’ve used to warm the water (4.18J per ml per °):
Erm = (Tfm-Ti)/600*4.18
Erh = (Tfh-Ti)/600*4.18
Erk = (Tfk-Ti)/600*4.18 the 600 comes from the volume of water you’ve heated up, and the Er is for real energy.
However you can now compute the energy drawn from the grid simply by using:
Em=Pm*60
Eh=Ph*60
Ek=Pk*60
And you can easily now compute the efficiency (r) of each apparatus being the ration of the real energy over the energy drawn from the grid:
rm=Erm/EM
rh=Erh/Eh
rk=Erk/Ek.
But I am not taking a lot of risks saying that you’ll find your MWO to be the most efficient (At this point it will obviously depend on the MWO indeed but they are the most efficient way to eat up water molecules).

YOU ARE ALL RONG

http://srimech.blogspot.com/2008/08/tea-making-with-gas-and-electricity.html

gas is slower and less efficient but cheaper.

kettle is faster and more efficient but more expensive.

after factoring the efficiency of the power station they are about equal in efficiency.

here ends the lesson.

Excellent stuff! I have to say juan’s confused the hell out of me but that’s just my tired brain trying to process all of the data.

I’m with Jon Taylor on this one. My gut feeling after factoring in all of the respective elements is that they’re about equal.

I like saucepan’s because they remind of camping whereas kettles….don’t! Not very scientific I know but there you go.

Guy Martin on making a cup of tea- 1min in 😀

[video]http://www.youtube.com/watch?v=a0845Vgy99E[/video]