Which takes less energy - boiling or microwaving water?

Question

this isnt a homework question lol

morons -- the lot of you -- boiling water, like on a stove, in a pot, or tea kettle. I think most people would make this assumption. STOVE VS MICROWAVE. got it?

And energy i mean total energy from the point of delivery to the consumer. Not the amount of energy needed to boil water.

This isnt a chemistry question. lol.

I dont think anyone boils water with laser guns, maybe over a fire? What else were you thinking? Maybe on the surface of the sun..

of course thanks to everyone else ^ _ ^

i liked the 5th answer.

What about in terms of distributing electric energy (to the microwave) vs gas (to the stove)

I still like the 5th answer. From a consumer POV, which takes less energy overall?

hmm.. nice one. 6

Answer 1

To heat water to the same temperature using either a burner or a microwave, i would guess that the microwave would use less energy. That's just because of the way microwave ovens versus oven burners work; the microwaves bounce around inside the oven until they're all absorbed, and they're typically only absorbed by water.

The burner, on the other hand, releases all sorts of heat into the air around it - waste energy - and has to heat the container of the water in order to heat the water itself. A microwave heats the water directly.

Of course, if you microwave water to boiling point, it won't actually boil. It'll stay superheated until something disturbs it...like a vibration or a shake. then it will start boiling - rather explosively, if the temperature is high enough.

Answer 2

Assuming we are talking like for like ie an electric kettle and a microwave and not a gas or electric stove to heat the kettle, then the most efficient potentially has to be the electric kettle. All of the electricity passing in the element is converted in to heat. There is no wastage at this point or loss, except for heating up the actual element itself and a little through the kettle body. However, the microwave will already have lost electrical energy in the conversion to microwaves. According to Wiki a typical microwave oven is only about 77% efficient with regards to heating the food. This however compares with 10% to 60% for a conventional oven so in cooking food microwaves are much more efficient.

However, these figures are for heating food not water. According to Wiki, an electric kettle is over 90% efficient (comparatively little heat energy is lost during the 2 to 3 minutes a kettle takes to boil water) and so for boiling water efficiently the kettle wins hands down and is almost as quick anyway.

Answer 3

Consider that boiling a pot of water on the stove (I did understand what you were after) can heat up the whole kitchen. By comparison, boiling the same quantity of water in a microwave is faster, and really only heats up the water. Even the cup that the water is in doesn't heat up much due to microwave absorbtion. The cup is mainly heated by the water through conduction. (For comparison, microwave an empty cup at the same time as your cup of water and see how much it heats up.)

This is one way to prove to yourself that the microwave is much more efficient. However, you'll still find that the stove is useful for boiling large quantities of water. Also, if it's winter time, and you've got the heater running in your house anyhow, it doesn't really matter which heat source you use. It won't affect your energy bill because the heater will just cycle on less to compensate for the extra heat coming from the kitchen.

Answer 4

Heating water under the wo conditions requires the same energy.
Under ideal conditons and assuming all the heat dissipated by the stove or the microwave goes to heat the mater then, since energy cannot be created nor destroyed, then it will be the same amount of energy and that is calculated as ( mass of the watey X specific heat capacity of water X change in temperature ).
But under ideal conditions, there is a considerable amount of heat lost by heating the surrounding, heating the element, heating the container and so forth, that means boiling water over a stove will require more energy that in a microwave because there is not much energy lost to heat other things than in an open stove.
Thanks

Answer 5

Actually it's pretty answerable.

Microwave wins hands down.

Microwaves are very efficient at keeping all the energy generated inside it (actually it'd probably kill or seriously injure you if it didnt). And water, being the polar stud that it is, is very, very good at soaking up the changing magnetic flux generated by microwaves (microwaves actually heat up the water molecules in everything, that's how it heats things). Stoves waste a lot of energy to the ambient atmosphere.

Answer 6

I agree with comments about the efficiency of the microwave and furthermore it is likely that one will be heating up only the exact quantity of water needed in a cup. However taking a broader view, there is often a lot of heat wasted in the generation of electricity (typically 55% or more is wasted in the cooling water). A gas burner, carefully adjusted, heating the needed quantity of water only, may achieve efficiencies of 50% or more so from this point of view the gas may be more efficient.

Answer 7

I guess it depends on the quality of the microwave oven, and stove.

I would like to say microwaving since the microwave is tuned to precisely heat up water molecules by resonance.... The stove on the other hand heats up everything, the stove itself, the air, the pot, and that is wasted energy.

Answer 8

This is an unanswerable question in its current form.

Boiling water refers to the process in which liquid water is changed from the liquid state of mater to the solid state of mater. This process requires that energy be inputted into the system in order to overcome the intermolecular forces of attraction between the water molecules....this amounts to what is known as the latent heat of vaporization.

Microwaving water simply means (to put it simply) passing microwaves into a body of water in order to increase its temperature.

Whether one boils the water in the process of microwaving it is not stated. One could microwave water from 0 degrees C to 100 degrees C and none of it boil away.
Whereas by definition, water must boil away in the process of boiling (obviously).

It is also not stated the amount of water which is microwaved, nor the amount which is boiled away.
One can assume that microwaving 10000 kg water from 0 to 100 degrees C takes more energy than boiling 1 gram of liquid water from 100 degrees C to 1 grams of steam at 100 degrees C.

This question desperately needs to be restated and more information needs to be supplied.

Are we to, perhaps, assume that you wish to compare two different methods of heating and boiling away equal amounts of water at the same initial temperature using two different methods of heating....a conventional stove top and a microwave?
There are, after all, several methods in which to heat water and boiling and heating are always the same thing.

Answer 9

Boiling water takes less energy, because with the microwave you are using electricity which is energy.

Answer 10

It takes the same amount of energy to boil a given quantity of water, the question is what is the most efficient method. To that I must reply, which is more important, the time it takes or the cost of your electric bill?