Are microwaves energy efficient?

[ballbaby]

I remember when microwaves first came out and they said they were economical because they just heated the food and nothing else. Is this true? Might it be more economical to heat water for your cuppa in there rather than a kettle?

Does no-one want to join my extremely important and interesting debate of microwave vs kettle? Posted this when I returned home after my Xmas do - too much red wine perhaps?

rather depends on the MW and the kettle conserned. if they are same wattage then which ever is faster at boiling the right ammont of water is more effient. i've not experimented ... but my hunch is kettle is quicker as MW not v fast at heating liquid as moloclues don't bounce so fast as in a solid. CMIIW.

Sara, for a second there I thought you were talking about midwives, not microwaves when you said MW. I thought what's a kettle got to do with a midwife?

Kettle maybe quicker but have you ever noticed the amount of electricity a kettle uses? the dial goes crazy....

thats why you ned to compare the wattages- a 1200w MW uses elec just as fast as an 1200w kettle. I've just looked in my kitchen and teh MW uses 1200w, the kettle 2520w. so, the kettle will need to be 2x the speed at boiling the same ammonut of water to use the same ammount of electrickery.
11 years ago i worked out that the tumble dryer in my rented place cost 1p a minute to use. I got into line drying very fast after that discovery.

There's something dangerous about heating it in the microwave, but I can't remember what.

[unhelpful icon]

If your liquid is very pure (i.e. plain water and not most tap water) and the vessel is very clean, it can get superheated. It looks fine, but when you pick it up it boils over on your hand.

This happens regularly in my lab, heating stuff for work not to drink, but for some reason never at home-what does that say about the purity and cleanliness of my cuppa!

Seriously, though, I avoid really BOILING liquids like that, just heating it a bit is all I attempt.