Which is more energy efficient: heating a given volume of water all at once, or in two batches?
I have an electric kettle, and a large urn of room temperature filtered water, which I use for tea. If I'm making tea for two people who aren't going to be drinking it at the same time, is it more energy efficient to boil the water separately, all at once, or no difference?
@Fishercat
I think it is more efficient to boil it separately, depending on how long there is between the two usages and if you want to make sure the second cup is as warm as the first.
The difference is the heat loss from the water left in the kettle after the first cup. When the water is left warm in the kettle the temperature will slowly decline. And if you want the second cup to be just as warm, you need to heat it again.
I can think of cases where it would be more efficient to boil it all at once, but I don't think that would ever apply to an electric kettle.
(if you were using an iron pot over a stove, boiling the water would require extra energy to heat up the pot as well, which you would need to do again for the next cup)
Fishercat
Spoonie Activist (he/him)