# Cost of boiling water **URL:** \ **Category:** Factual Questions\ **Created:** [May 20, 2023, 10:17am UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321 "2023-05-20T10:17:46Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [May 20, 2023, 1:49pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/21 "2023-05-20T13:49:24Z")
> [@commasense](#): > > (Are we going to be able to embed videos again soon?) You still can. Just add a / to the end of a YouTube video URL. Just know you will NOT be able to edit your post after that until this problem is sorted. [![](https://img.youtube.com/vi/_yMMTVVJI4c/maxresdefault.jpg "Why don't Americans use electric kettles?") ](https://www.youtube.com/watch?v=_yMMTVVJI4c) ---
**Author:** ![Ike\_Witt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ike_witt/32/283_2.png) [@Ike\_Witt](https://boards.straightdope.com/u/Ike_Witt)\ **Post date:** [May 20, 2023, 2:03pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/22 "2023-05-20T14:03:44Z")
Crap, I was going to link to that video… ---
**Author:** ![Pardel-Lux](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pardel-lux/32/20182_2.png) [@Pardel-Lux](https://boards.straightdope.com/u/Pardel-Lux)\ **Post date:** [May 20, 2023, 2:12pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/23 "2023-05-20T14:12:07Z")
Just for the record, I use my microwave oven to heat up the dishes before serving when I cook something that cools fast, for instance thin fish fillets or small omelettes. Put the dish in the microwave, put a couple of spoonfuls of water it, cover with the next dish and repeat for as many dishes you need. Start the microwave set at high for a minute, leave the door closed when it stops. When the meal is ready, take the warm dishes from the microwave, pour the water away and serve the food. I don’t think this costs me more than 2 or 3 € a year and is worth it. For tea an electric kettle is perfect, specially if you invenst in the ones with adjustble temperature. Some teas only need 60°C\*, others boiling water, others anything in between. Using the right temperature for the different tea varieties is noticeably better. \* I am not asking you to _[convert](https://boards.straightdope.com/t/how-do-you-feel-about-converting-to-the-metric-system/978666)_ to the metric system, it is not a religion, I just ask that if you are interested in how much 60°C are in Fahrenheit, _you_ look it up, not me. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [May 20, 2023, 2:15pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/24 "2023-05-20T14:15:16Z")
Nyah, nyah! 😁 ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [May 20, 2023, 3:37pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/25 "2023-05-20T15:37:55Z")
> [@Chronos](#): > > Don’t even get me started on the whole brouhaha about “vampire” wall warts. The scare blurbs always talk about how much power is wasted across the entire US per decade, or whatever, and never mention that it’s a few cents per person per year. It’s almost certainly more cost to take the effort to unplug them. Wall warts ain’t what they used to be. Up until about 20 years ago, they used a transformer, a rectifier, and a filter to convert high-voltage AC into low-voltage DC. Even when you weren’t using one to power a device, they still dissipated significant power internally as heat in their components. Modern wall warts use switched-mode power supplies, which are not only more efficient when powering a device, they also consume almost no energy when not powering a device. > **[AC adapter](https://en.wikipedia.org/wiki/AC_adapter)** > > An AC adapter or AC/DC adapter is a type of external power supply, often enclosed in a case similar to an AC plug. Other common names include wall charger, power adapter, power brick, and wall wart. Adapters for battery-powered equipment may be described as chargers or rechargers (see also battery charger). AC adapters are used with electrical devices that require power but do not contain internal components to derive the required voltage and power from mains power. The internal circuitry Exter... ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [May 20, 2023, 3:58pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/26 "2023-05-20T15:58:58Z")
> [@Whack-a-Mole](#): > > > [@LSLGuy](#): > > > > As to tongue-burning, try running it at half power for twice as long or 1/3rd power for 3x as long. The food will be much more evenly heated and takes zero additional effort. > > That’s (usually) what I do. If you heat food at 100% the outside gets super hot and nuked and the inside is cold. Yep. Many varieties of prepared frozen foods like Stouffer’s contain directions like “_Microwave on high for ‘x’ minutes. Peel back film, stir, and re-cover. Microwave on high for ‘y’ more minutes. Let stand for 2 minutes._” None of which is necessary. I just add up x+y and nuke at 50% power for twice the time while I go about doing other things. Works perfectly, and no need to let stand. Might not work for special products that actually require high power, like those with reflective foil packaging used for microwave browning. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [May 20, 2023, 4:09pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/27 "2023-05-20T16:09:58Z")
Totally agreed in general. But with a situational caveat … In the days before near universal turntables in microwaves, the “stir” in the middle was actually pretty necessary because of the very uneven heating pattern inside the oven cavity. Which the turntable evens out by the very low-tech method moving the food effectively randomly through the uneven standing waves. Many cheap, small, or crappy microwaves, like those often found in office lunchrooms, lack a turntable. Plus all those old raggedy ones where the turntable motor has failed or the glass platter has been broken & not replaced. Absent a turntable, stirring mid-nuke is real valuable for those things that can be stirred. With a turntable your (X+Y) \* 2 at 50% power works great. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [May 20, 2023, 4:32pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/28 "2023-05-20T16:32:48Z")
> [@Whack-a-Mole](#): > > You’re better off burning the gas directly to heat the water. This is demonstrably not true. Perhaps he was just pointing out that using gas to generate electricity was inefficient. People have pointed out that the difference is marginal and I was well aware of that when I asked the question. I also did not ask about costs because self-evidently, the costs will depend on tariffs. Notwithstanding Mighty Mouse’s non-scientific test, my WAG is that an electric kettle is best, provided that the volume of water remains the same. Gas comes a poor third because much of the energy is wasted. As for tariffs - I am currently paying 31.24p per kWh for electricity and 9.74p for gas. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [May 20, 2023, 4:36pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/29 "2023-05-20T16:36:25Z")
> [@bob\_2](#): > > I also did not ask about costs because self-evidently, the costs will depend on tariffs. Err…“cost” is in the title of the OP. Your OP. Are you changing the parameters of the question? ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [May 20, 2023, 4:37pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/30 "2023-05-20T16:37:26Z")
> [@bob\_2](#): > > Notwithstanding Mighty Mouse’s non-scientific test What’s nonscientific? He did an actual controlled experiment and measured all the key variables. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [May 20, 2023, 5:01pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/31 "2023-05-20T17:01:29Z")
Mistake on my part. I do finish the question saying: _someone on this board with the skills to calculate which is the most efficient **in terms of kWh of energy.** _ ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [May 20, 2023, 5:06pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/32 "2023-05-20T17:06:09Z")
He didn’t allow for the 25% difference in volume. ---
**Author:** ![Mighty\_Mouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mighty_mouse/32/7776_2.png) [@Mighty\_Mouse](https://boards.straightdope.com/u/Mighty_Mouse)\ **Post date:** [May 20, 2023, 5:09pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/33 "2023-05-20T17:09:20Z")
> [@puzzlegal](#): > > > [@bob\_2](#): > > > > Notwithstanding Mighty Mouse’s non-scientific test > > What’s nonscientific? He did an actual controlled experiment and measured all the key variables. Thank you. I can assure you that I have seen hundreds of millions in expenditure approved on the strength of a lot less rigorous measurements. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [May 20, 2023, 5:10pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/34 "2023-05-20T17:10:18Z")
From the video it seems the answer is an electric kettle is most efficient at boiling water (least energy consumed at a home consumer level). And, of course, there are better and worse kettles when it comes to efficiency. ---
**Author:** ![Mighty\_Mouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mighty_mouse/32/7776_2.png) [@Mighty\_Mouse](https://boards.straightdope.com/u/Mighty_Mouse)\ **Post date:** [May 20, 2023, 5:12pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/35 "2023-05-20T17:12:23Z")
Wait, what? I measured what it would take to boil 14 oz of water (the size of my mug). The excess 4 oz is just waste, but it is unavoidable waste. You might was well only account for the cost of the electricity used and not the amount lost in transmission. But the utility company is going to charge you for both. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [May 20, 2023, 5:19pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/36 "2023-05-20T17:19:56Z")
> [@Machine\_Elf](#): > > Wall warts ain’t what they used to be. Up until about 20 years ago, they used a transformer, a rectifier, and a filter to convert high-voltage AC into low-voltage DC. Even when you weren’t using one to power a device, they still dissipated significant power internally as heat in their components. Modern wall warts use switched-mode power supplies, which are not only more efficient when powering a device, they also consume almost no energy when not powering a device. Worth mentioning, however, that another “feature” of wall warts using cheap switching power supplies is that they typically generate electrical noise. Not usually something one would notice or care about, but one may care very much if using IEEE 1901 type powerline adapters for home networking. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [May 20, 2023, 5:34pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/37 "2023-05-20T17:34:52Z")
> [@bob\_2](#): > > He didn’t allow for the 25% difference in volume. He did. He heated the minimum amount he needed to produce a cup of hot water using different tools in his household according to their safe operating directions. The fact that you need to use a little more water if you use the kettle (or a pot on the stove) is a critical component of the hypothesis that you might save money using the microwave. ---
**Author:** ![Kropotkin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kropotkin/32/18045_2.png) [@Kropotkin](https://boards.straightdope.com/u/Kropotkin)\ **Post date:** [May 20, 2023, 6:02pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/38 "2023-05-20T18:02:25Z")
I heat water for tea in a kettle on the stove, but I don’t waste the extra water: it gets used for a neti pot solution or a hummingbird sugar solution. I don’t need to boil water for either, but this way we avoid the infinitesimally small chance of snorting a brain eating microbe with the neti pot and give the hummers a cleaner brew. So, again, a pretty small difference between microwave and kettle. We do save money and resources of some kind by not having a microwave. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [May 20, 2023, 9:27pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/39 "2023-05-20T21:27:29Z")
> [@Mighty\_Mouse](#): > > Thank you. I can assure you that I have seen hundreds of millions in expenditure approved on the strength of a lot less rigorous measurements. Corporations will pass a $billion project with a nod, but spend an hour debating the design of a bicycle shed. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [May 20, 2023, 10:19pm UTC](https://boards.straightdope.com/t/cost-of-boiling-water/984321/40 "2023-05-20T22:19:12Z")
> [@Machine\_Elf](#): > > Even when you weren’t using one to power a device, they still dissipated significant power internally as heat in their components. For some values of “significantly”. If it’s, say, a watt per transformer, that means that leaving it plugged in continually will add up to 8.8 kWh per year. Around here, electricity costs around ten cents per kWh, so that’d be less than a dollar a year. And that’s counting the entire year as waste time, but obviously the reason you have the device is because you use it sometimes. [Previous page](https://boards.straightdope.com/t/cost-of-boiling-water/984321.md?page=1) [Next page](https://boards.straightdope.com/t/cost-of-boiling-water/984321.md?page=3)