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I'd be interested in an overall energy use comparison between a kettle and a hot water tap. I know lots of people who boil far too much water for a single cup o

I'd be interested in an overall energy use comparison between a kettle and a hot water tap. I know lots of people who boil far too much water for a single cup of tea or coffee (partially due to kettle designs).

TheSpiceIsLife 2y ago
<opinion> This problem is solved in its entirety by simply microwaving a cup of water. No wasted water. If the same / similar cup is used, one can choose the desired temperature of the resultant hot water simply by varying the time. Seasonal variation of ambient water temperature may need to be taken into account. I tend not to drink coffee, and I prefer to make tea with less-than-boiling water. YMMV </opinion. Now that I’ve written that, I’ll have to put a power meter on the microwave and a kettle and report back with the results. My kettle recently broke and I hadn’t intended to replace.
- ndsipa_pomu 2y ago
  I'd guess that a microwave would "waste" more energy as it's got moving parts and the energy isn't completely directed to heating the water. A kettle also "wastes" some energy as you end up heating the kettle too (from the hot water). If a microwave was more efficient, I'd expect to see premium kettles that used microwaves instead of a simple heating element, though maybe there'd be design problems with preventing leaking microwaves.
  - TheSpiceIsLife 2y ago
    Agree, at least to some extent. For my use cases, I’m not looking to actually boil the water, bringing it up to 80 plus degrees suffices. The inefficiency kettles bring is the tendency of certain users to heat way more water than their immediate needs.
- prewett 2y ago
  I've tried that, and there are two problems. One is that water has a tendency to superheat and then boil all over the place when you put the tea in, or it suddenly produces a big bubble and water goes everywhere. The other is that it is hard to get a consistent temperature. Even if you measure it with a thermometer it seems problematic (although perhaps the grocery store thermometers go out of calibration easily). If you're doing herbal tea it might not matter as much, but for something like Chinese green tea, it was always hit or miss. I bought the Bonavita kettle as soon as I found out about it, and now I always have consistent tea with no fuss or mess.
  - TheSpiceIsLife 2y ago
    My daily driver, a flatbed Panasonic microwave, does a good enough job, but yeah actually boiling the water in a microwave is a recipe for a way too hot cup, and half the water boiling over. 220ml, regular ceramic mug, one minute forty, does what I need, but I’m not tea or coffee connoisseur, just a prole with a box of Twinings loose leaf. Thanks for the kettle reference, I have been meaning to find a temperature controlled unit. I recently picked up an inexpensive Thomson branded electric frypan with digital temperature and time controls, well impressed.
alias_neo 2y ago
I don't have a comparison to a kettle because I don't have one, but our Quooker tap took a fraction of a kWh over a couple of months that I measured the energy usage, and my wife uses it daily for tea and we use it most days for boiling water for things like cooking. The 3L tank that holds the hot water, under the sink is well insulated and it takes almost nothing to keep it at temperature. Given that it uses such negligible energy that I needn't care, the benefits of instant boiling water whenever we like and not having an extra appliance no the counter-top make it a clear winner for us.
- frereubu 2y ago
  Interesting, thanks. I really like the idea but the thing I'd miss from our kettle is the ability to change to lower temperatures for different kinds of tea. You shouldn't really use boiling water for some kinds of green tea, for example. I guess you can mix in some cold water to reach close to the right temperature, but I'd miss the convenience.
  - alias_neo 2y ago
    I've never come across a kettle that changes temperature, or is it that you can stop it boiling when you feel it's about right? My wife drinks tea (I'm a coffee drinker) and I make tea (just simple, English Breakfast with milk) for her quite often, and we both use it for cooking. It was something she'd always wanted, and she's not much into "gadgets" but she's been very happy with this, so I'm happy.
    - ndsipa_pomu 2y ago
      > I've never come across a kettle that changes temperature, or is it that you can stop it boiling when you feel it's about right? There's several around - I've got one that allows you to choose between 70°C, 80°C, 90°C and boiling (along with a keep-warm option that's never used). I use the 80°C option all the time for making coffee (Aeropress) and use the 70°C for things like green tea (black tea should be 100°C of course). It's a mistake to use boiling water when making coffee - it'll extract a bitter flavour.

TheSpiceIsLife 2y ago

<opinion> This problem is solved in its entirety by simply microwaving a cup of water. No wasted water. If the same / similar cup is used, one can choose the desired temperature of the resultant hot water simply by varying the time. Seasonal variation of ambient water temperature may need to be taken into account. I tend not to drink coffee, and I prefer to make tea with less-than-boiling water. YMMV </opinion. Now that I’ve written that, I’ll have to put a power meter on the microwave and a kettle and report back with the results. My kettle recently broke and I hadn’t intended to replace.

ndsipa_pomu 2y ago
I'd guess that a microwave would "waste" more energy as it's got moving parts and the energy isn't completely directed to heating the water. A kettle also "wastes" some energy as you end up heating the kettle too (from the hot water). If a microwave was more efficient, I'd expect to see premium kettles that used microwaves instead of a simple heating element, though maybe there'd be design problems with preventing leaking microwaves.
- TheSpiceIsLife 2y ago
  Agree, at least to some extent. For my use cases, I’m not looking to actually boil the water, bringing it up to 80 plus degrees suffices. The inefficiency kettles bring is the tendency of certain users to heat way more water than their immediate needs.
prewett 2y ago
I've tried that, and there are two problems. One is that water has a tendency to superheat and then boil all over the place when you put the tea in, or it suddenly produces a big bubble and water goes everywhere. The other is that it is hard to get a consistent temperature. Even if you measure it with a thermometer it seems problematic (although perhaps the grocery store thermometers go out of calibration easily). If you're doing herbal tea it might not matter as much, but for something like Chinese green tea, it was always hit or miss. I bought the Bonavita kettle as soon as I found out about it, and now I always have consistent tea with no fuss or mess.
- TheSpiceIsLife 2y ago
  My daily driver, a flatbed Panasonic microwave, does a good enough job, but yeah actually boiling the water in a microwave is a recipe for a way too hot cup, and half the water boiling over. 220ml, regular ceramic mug, one minute forty, does what I need, but I’m not tea or coffee connoisseur, just a prole with a box of Twinings loose leaf. Thanks for the kettle reference, I have been meaning to find a temperature controlled unit. I recently picked up an inexpensive Thomson branded electric frypan with digital temperature and time controls, well impressed.

alias_neo 2y ago

I don't have a comparison to a kettle because I don't have one, but our Quooker tap took a fraction of a kWh over a couple of months that I measured the energy usage, and my wife uses it daily for tea and we use it most days for boiling water for things like cooking. The 3L tank that holds the hot water, under the sink is well insulated and it takes almost nothing to keep it at temperature. Given that it uses such negligible energy that I needn't care, the benefits of instant boiling water whenever we like and not having an extra appliance no the counter-top make it a clear winner for us.

frereubu 2y ago
Interesting, thanks. I really like the idea but the thing I'd miss from our kettle is the ability to change to lower temperatures for different kinds of tea. You shouldn't really use boiling water for some kinds of green tea, for example. I guess you can mix in some cold water to reach close to the right temperature, but I'd miss the convenience.
- alias_neo 2y ago
  I've never come across a kettle that changes temperature, or is it that you can stop it boiling when you feel it's about right? My wife drinks tea (I'm a coffee drinker) and I make tea (just simple, English Breakfast with milk) for her quite often, and we both use it for cooking. It was something she'd always wanted, and she's not much into "gadgets" but she's been very happy with this, so I'm happy.
  - ndsipa_pomu 2y ago
    > I've never come across a kettle that changes temperature, or is it that you can stop it boiling when you feel it's about right? There's several around - I've got one that allows you to choose between 70°C, 80°C, 90°C and boiling (along with a keep-warm option that's never used). I use the 80°C option all the time for making coffee (Aeropress) and use the 70°C for things like green tea (black tea should be 100°C of course). It's a mistake to use boiling water when making coffee - it'll extract a bitter flavour.