It's also quite a helpful metric.

Most British people are aware that the national grid used to spend a lot of time making sure they had the power available to draw during the commercial breaks of mass-media TV events (series finales, half time in a cup match etc) purely for the nation boiling water with electric kettles en masse.

Great intersection of hard science (energy necessary to boil water + extremely efficient energy transfer) and everyperson knowledge. Good journalism!

Makes you wonder if the US idea of using just 110 volts isn't better... not from an individual viewpoint (slower to boil water) but from the grid perspective.

The US grid (the last-mile bits anyway) isn't 110 volts, it's 220. It's just our houses that are wired for (mostly) 110 V.

Edit: I would love to see some sort of hybrid 110/220 V residential wiring/plug standard take hold in the US. It would require more expensive cable in the walls (since you need one additional conductor) and plugs, but it's totally doable. Most electrical products and appliances made these days are easily converted between 110/220, or run just fine on either.

There is NEMA 14, which has hot,hot,neutral,ground, but I don't think anything lower than 20amps is available, and that's a locking one, 30 amps is available without locks, but 30 amps at 220v is a lot of power for household outlets. You'd need larger wire in the walls, not just more of them.

Any sort of outlet upgrade would need a really good plan for how to make it viable, because even if 100% of new construction used the new outlet, it would be decades before you could sell devices that relied on it.

I have a 20A 220 circuit for an electric kettle with multiple 6-15Rs. It has a 20A gfci breaker.

You could include a second cable with the teapot, and wire it to work with 110 or 220 depending on which cable is used. This is already reasonably common. I have plenty of useless European cables laying around to prove it.

> The US grid (the last-mile bits anyway) isn't 110 volts, it's 220. It's just our houses that are wired for (mostly) 110 V.

Similarly, in most of continental Europe phase-to-phase is 400V but most outlets are 230V. E.g. in my apartment only the stove has a 400V three-phase (4-wire) connection.

but 3phase (120degrees) is a lot better for powering motors than the 2 phase one in the US

3-phase is available in USA, but it's typically not provided to residences.

of course, the heavy motors/industrial equipment loves 3 phase AC. Higher voltages allow lower losses in the conductors, hence less copper needed everywhere incl. small motors as the current us lower through and through.

I kinda like that all but a couple outlets in my house can't kill me.

Also, I boil my water on an induction stove plugged into 50 amps at 220 volts. I'm not waiting around, to put it mildly.

110v can easily kill you. It's a little harder to get a good solid connection through your body and into the ground than 220v. But it certainly can and does happen.

Amps kill, not volts. Hence high voltage low amp Tesla coil spark shows.

Thats not quite accurate- it is true that high amp current is deadly in many scenarios, but it takes both amps and volts to kill. High amp, high voltage current is a killer for sure, but high current at sufficiently tiny voltages is not necessarily deadly. Similarly, high voltage at low currents is usually not deadly (but can be very painful).

You need to be introduced to a classic: https://www.youtube.com/watch?v=XDf2nhfxVzg

Your comment is completely irrelevant to wall sockets because they can all supply more than a tenth of an amp.

High voltage from a Tesla coil not only has low average current, but is subject to the skin effect. So while it can still cause a painful shock to your superficial sensory nerves, not much of that energy ends up in contact with the motor nerves.

TL,DR: you probably don't want to be shocked by a big Tesla coil, even though it won't kill you.

Never heard of anyone getting killed by the 230V power in Europe. A few people I know touched it and it does hurt.

Perhaps it's because all houses have residual current devices which trigger much faster than fuses if current leaks to earth (eg through a person).

30A at 400V is how we roll in the EU.

Wow. A typical induction hob in the UK is 32A at 230V. 230V is of course the nominal voltage of a single phase, although in practice in the UK the voltage is closer to 240V.

That's only 7.35kW of power. Do you have significantly more powerful cookers?

400V is only used for stoves or instant water heaters, but e.g. our stove uses 11kW actually.

If you don’t have these amounts of energy available, the temperature your instant water heater can reach or the speed with which you can cook obviously suffers (which I suspect is one of the reasons why americans prefer gas stoves so much).

the 3phase is used for motors - a lot more efficient (and the better power factor) than the single phase ones.

For industrial applications definitely, but at home there's few people who power motors with triphase or five phase power.

these are 3-phase stoves, they require a certified electrician to install, because they don't have plugs and there's no wall socket - just a place into which you can easily connect cables.

That makes sense. In the UK you can buy induction hobs that plug into sockets, but they are limited to a measly 3.7kW or there abouts. A nicer 32A induction hob needs hardwired (single phase).

You can have upgrade your domestic supply to three phrase, but AFAICT it's uncommon. Perhaps with electric cars and induction hobs replacing natural gas and petrol, it will become more common.

You could just run US-style appliance circuits to your kitchen, etc. Those are sometimes three conductor and other times four conductor.

However, I doubt it'd pass inspection if they were easily accessible from the counter-top.

If you're going to flout building codes anyway, it'd probably be easier/more practical to just run circuits with foreign outlets instead. Also, it might be easier to find appropriate GFCI breakers.

Use 6-15R or 6-20R. I think it would pass inspection because most safety requirements around gfci and afci don’t apply to 240V circuits

They do now, but only when accessible by a person. Even car charging station outlets do (even though every car charging station has gfci built in...)

Ah looks like this was a change in 2017. With any outlet there’s no guarantee what will end up plugged in so it’s logical to require it even if the purpose is an EV charger.

Thanks!

EU is on 50hz AC, where as the US is on 60hz. It would work fine for purely resistive appliances, and possibly devices with switching mode power supplies, but some devices would be unhappy plugging in to the wrong frequency at 220V.

I'm not sure about the phase alignment but that may be an issue as well. US is split phase, but Europe has 220 on a single conductor?

it's 230 (+-10%) nominal not 220. At my house it's around 235. It's 230v phase/live to neutral and 400V between live wires in 3phase. Nowadays 3-phase (120degree between each) is a commodity.

In my part of USA the typical voltage between the two sides of a breaker box is 240V. It actually moves around a bit below that value, but doesn't seem to ever exceed 240V. I think most consumer devices have the circuitry necessary to survive such variation, but I have seen some (expensive) professional equipment fried in an instant...

Thanks for that. Sounds wonderful compared to the typical 200 amp, split phase service we commonly have in the US.

How many non-switching power supplies will care either?

110v does nearly halve your peak power draw... But the transformers have a bit of added complexity and in homes and businesses you need thicker wire to move the same amount of power.

Power is power. To the extent 110V is slower to boil water, it's a reflection of either inadequate power delivery capacity due to the higher currents required, or wasted heat in places other than the kettle. Either way, heat gets lost over time.

You're almost always better off with higher voltage and less current, when given a choice. An obvious exception being when you get shocked. :-P Or when corona losses come into the picture.

No, it’s absolutely not. They consume a lot of power on average as far as I remember. They have just more transmissions loss at a lower voltage and I guess that it would be a pain to use a normal induction cooktop with 9-10KW at 110V.

Yes, and some places world cup viewership can take down the grid!

Whilst kettles are used as the unit of measurement the main driver of power consumption spikes during those breaks was electric pump for toilet cisterns.

Wasn't there a relevant Tom Scott video on the subject?

https://www.youtube.com/watch?v=6Jx_bJgIFhI about pumped hydro at Dinorwig Power Station

That's enough energy to boil those kettles dry, if my calculations are correct. To bring them to the boil, 59MJ would run about 600 kettles.

Water has a specific heat capacity of 4184J/kg/C. Lets say to get to the boil you need to go from 20C to 100C and that a kettle holds 1.75L.

59MJ / (80C * 4184J/kg/C) = 176kg ~= 176L ~= 100 kettles.

Water has a latent heat of vaporization of 2260 kJ/kg. So to boil it dry:

59MJ / (80C * 4184J/kg/C + 2260 kJ/kg) = 22kg ~= 22L ~= 12 kettles.

I have no idea what the journalist calculated.

I suppose it's possible that the "standard" kettle size is ~3L. They don't seem too uncommon on Amazon.

I think the journalist is calculating load capacity. A 1500A @120V kettle requires 0.18 MW. Rounding up, 60 kettles requires 12 MW. It's not how much water you can boil, it's how many kettles you can run at the same time.

59MJ over 5 seconds would be 11GW, so if it was load, that would be 6000 2kw kettles!

Although obviously those kettles wouldn't achieve much in those 5 seconds!

I'm way off. I meant 15A. Now I've no clue what the journalist is calculating.

They should start selling 1500A kettles though. Bring a pot of water to the boil instantly.

But they’re UK, so it wouldn’t be 110V. Nice try, though!

A 180kW kettle ?! Great Scott !

Did you factor in the inefficiencies of the power distribution grid and the heating element of the kettle? I'd say the journalists are just repeating what they've been told by the scientists, and the scientists factored inefficiency in on a calculation similar to your first.

There may exist inefficiencies in the transfer of heat from the element to the water, but there is no such thing as an inefficient heating element. All of the power it uses will be converted to heat. Take a light bulb for example. When used to light a space, the inefficient part would be the energy that is lost to heat. The rest is converted to light, but as soon as that light hits an object, it's converted to heat. So even a light bulb is a perfectly efficient heating element.

With this in mind, you aren't saving any money on your electric bill by turning off lights when your furnace is on.

The internal heating element isn’t strictly speaking 100% efficient on AC as it’s producing a changing electric field etc. It’s just generally ignorable in practical terms.

Presumably heat dispersing into the air rather than into the water would be an example of an inefficient heating element.

The kettle is also losing a lot of heat to the air in the room.

Nope, I didn't factor in anything like that. Also kettle's don't actually heat every ml to 100C so there's some fudge in the other direction. I mostly was just getting nerdsniped.

Thermodynamics is very good at sniping nerds. The first law is basically a universe builder. The second law is maybe a universe destroyer? :)

Maybe they meant from a frozen solid state?

Are you referring to a morning kettle of tea or an afternoon kettle of tea?

an african or european kettle?

Maybe two kettles could boil the water together?

I thought they were these Kettles: https://youtu.be/ieKTU94-BgI

Good at math, but I'm not sure they could boil any water.

Yes but how many football fields can that throw a beer can?!

African or European beer cans?

Most importantly, US or rest of the world football?

You'd probably be surprised to learn that the UK is not at the top of the list of countries with the highest tea consumption.

https://en.wikipedia.org/wiki/List_of_countries_by_tea_consu...

Not even remotely surprised. I'm decently surprised they made it to number 4; I thought some southeast asian countries might have a higher per-capita tea consumption. Come to think of it, I think the list is probably highly skewed towards countries that import their tea and countries with local tea production will be a lot harder to pin down more accurately. Many countries missing from the list as well!

There are other "oddities" that make me suspicious. e.g. Saudi Arabia and UAE have extremely similar native population (bedouin Arab origins) and neither culturally drink black tea, but KSA ranks much higher than UAE. My immediate guess is the massive (underpaid) southeast asian labor force in KSA¹, which I know firsthand consume tea ceaselessly - but India supposedly has a lower per-capita consumption rate than the UAE. In fact, I'm sure both KSA and UAE are up there because of their foreign laborers, lending credence to my suspicion that countries with local tea production (such as India) are massively under-represented in that list.

¹: KSA does admittedly have a higher percentage of Levantine and North African permanent residents.

It's strange to me how low India is on the list. As an Indian all the Indians I know drink huge amounts of tea. Might just be an economics thing-- they can't afford to buy as much tea as they'd like to. That or it's something to do with the way the stats are collected

Actually, tea is about as cheap as clean water there. I commented separately, but tl;dr I think local tea consumption in countries that produce tea is being massively undercounted.

As an Indian living in the Netherlands, I suspect you're correct. Coffee is drunk here similar to how tea is drunk in India, and the Netherlands is the top #1/2 in per Capita coffee consumption. However, tea in India is often tied to a routine (eg time of day) while here it's more of an opportunistic thing (after a big meeting in the break).

Ireland is #2? As a culturally ignorant American, that _does_ surprise me.

I much prefer an Irish breakfast to an English breakfast tea. It’s stronger and has a distinct taste (although I didn’t like it as much initially.)

We are absolute fiends for tea.

Just learned new slang for "whiskey". Thank you.

The box of Barry’s in my drawer (I’m in America) agrees with you

Ah go on, go on, go on.

The source at the origin of the data is paywalled but there’s no way this is representative. Japan and Taiwan surely must have higher consumption than that. As someone else noted, wouldn’t be surprised if this is purely based on import statistics and therefore ignores domestic consumption.

...for five seconds, no less. Just now beating a record set back in 1997.

That sentence really hit me. Is that really only how far we've come? If so, the pace is so glacial that...I don't know, maybe this isn't worth it?

was it British Teapot Units all along?