Electric Kettle or Gas?

Volcano

I think its been covered here before but basically:

To boil a fixed amount of water will always require a fixed amount of energy, whatever that source of energy.

Electric kettles are very efficient; a cheap one with a clear, graduated scale allows you to boil just what you need. A hob kettle hasn't got this convenience and will probably be more expensive for the initial purchase.

Bongedone

I would add that you want an electric kettle with a concealed element so that you can only boil what you need.

Have a look at the Eco Kettle:

http://www.ecokettle.com/

KimYeovil

Bongedone wrote: »

I would add that you want an electric kettle with a concealed element so that you can only boil what you need.

But surely a concealed element is less efficient? A small, flat, low-slung element would be better. What is more, an unconcealed element is more likely to be replaceable.

And what about a small quantity of water not generating enough pressure to trigger the automatic switch-off? I'm always of the opinion that the one or two times I leave the kettle and it carries on bubbling away more than offsets the losses from covering an element.

Magentasue

I have replaced our perfectly adequate electric kettle with a hob kettle. Research suggested there wasn't much difference in the cost of boiling a kettle on the gas hob (more energy but lower kwh cost) or using an electric one (more expensive per kwh but more efficient use of energy). This is what I've found:

- my hob kettle whistles so I never put it on, walk away and forget about it. It calls me.
- it's more difficult to judge how much water I'm boiling but I've learned to judge it. Turn tap on and count to six for two cups.
- my kitchen has one worktop and two double sockets - hob kettle has obvious advantage for me there.
- I've lost count of the electric kettles I've bought. I suspect my gorgeous cherry red kettle will last a lifetime

kkkatie

Thanks Magentasue, thats just what I was looking for. I'll look into the eco kettle idea too. However, I think I've fallen in love with a fab aqua blue Le Creuset whistling kettle and having done a bit for research have found it reduced from £55 to £34, bargin.

Thanks again all that replied.

Penelope_Penguin

Magentasue wrote: »

I suspect my gorgeous cherry red kettle will last a lifetime

That sounds lovley :T Can you tell me where it's from, please?

I'll add this to the exisitng thread on this subject, to keep ideas together.

Penny. x

Magentasue

kkatie and penny, my kettle is a Lecreuset. This one: http://thecookskitchen.com/browse_2484

I can'r remember where I got mine from but it was £30. I've seen them for the same price or less in TKMaxx. I went for this one because it's larger than some, the 'whistle' is attached so can't go missing and you don't need a cloth to 'open' the spout or lift the handle.

Bongedone

KimYeovil wrote: »

But surely a concealed element is less efficient? A small, flat, low-slung element would be better. What is more, an unconcealed element is more likely to be replaceable.

And what about a small quantity of water not generating enough pressure to trigger the automatic switch-off? I'm always of the opinion that the one or two times I leave the kettle and it carries on bubbling away more than offsets the losses from covering an element.

All the eco kettles have a concealed element. It allows only one cup of water and also stops the element furring and lowering the efficiency. To be honest I am not sure if the element is concealed or that the element is a flat plate.

I have one of those eco kettles from the link. I was given it free to test. So far it is very fast and has never stayed on.

TerFar

s_baker wrote: »

Isn't the microwave the most energy efficient way of boiling water?

No. Microwave ovens are very inefficient. They are convenient, but not efficient.

blueskyabove

There really is an awful lot of nonsense being written about this. First cost and efficiency are not the same thing - something that costs less is not necessarily more efficient. Second, time and efficiency are not the same either - boiling a kettle of water quickly does not mean that the process used to do it is more efficient, just quicker. To do this right, you have to take a "whole system" view.

It takes a specific amount of energy to boil a liter of water whatever fuel you use. Efficiency in the use of the fuel to do this is related to the rate of heat transfer from the heat source (element or gas ring) to the water and the extent to which some heat is lost to the surrounding air in the process. It is also related to the percentage the original calorific value of the fuel reaching your kitchen. In the case of electricity, you are accessing around 30% of the original value because of all the mechanical and transmission losses involved in converting fuel (often gas!) into electricity and getting it to you. With gas, the losses are massively less so you get 70% to 80% of the original calorific value of the fuel. So, on this score, gas wins hands down and you are effectively burning it “at source”.

An electric element is effectively fully immersed in the water in an electric kettle so heat transfer from heat source to water is necessarily more efficient with less heat loss to the surrounding atmosphere. A gas kettle depends on an external heat source heating the kettle itself from the outside with this heat transferring to the water inside. This is less efficient than an electric kettle in terms of heat transfer and there are heat losses to the surrounding atmosphere. One up to electricity but still not necessarily a winner.

However, as with a lot of these things, some of this is down to user behaviour – just like your miles per gallon in your car is as much to do with driver technique as it is with the car itself. So ..

Boil only the amount of water you need so you don’t waste fuel and use it immediately it has boiled so that you don’t reheat it. The electric kettle will turn off when it has boiled but, unless you have one that makes a noise when it is done, you will need to be on hand to use the water as soon as it is ready. For a gas kettle, put it on a low light so that it matches the rate of heat transfer from kettle to water as closely as possible. As a rule of thumb, if the kettle handle gets hot then the light is too high. Use a whistling kettle to tell you when it is ready and turn it off when it does whistle and use the water immediately. The gas kettle will take a lot longer but, if you have done it the right way, it will waste less fuel because it is effectively burning the fuel “at source” at 70% - 80% of its original value as I said above, it will be more efficient overall. If you really can’t get you head round using a gas kettle and are always in a hurry, buy an eco friendly insulated electric kettle and use that sensibly to minimise the waste of the 30% of the original energy you are getting through your 3 pin plug.