Americans don't use electric kettles — or at least it's very rare. This is unlike Britain, where electric kettles are standard for boiling water.

An electric kettle, typically made of plastic or steel, has a heating element on the bottom. The kettle is plugged into an electrical outlet, which powers the coil and heats up the water.

It looks like this:

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Or this:

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Americans mostly use stove-top kettles. The kettle is filled with water and then heated on a gas or electric stove. The water boils, producing steam, which then flows out of the kettle spout producing a whistle. The whistle signals that your water is ready and you should turn off the stove.

Here's that process in action:

I'm American, so when I moved to the UK, I was surprised that it was difficult to find the standard stove-top kettle that I had grown up with. They are almost all electric.

The reason for this appears to be related to the voltage in America, which is lower than the voltage in the UK. A physicist and science teacher in the UK explains this on his blog MrReid.org.

Most homes in the US operate on 100-127 volts, whereas the UK and many other countries use between 220 and 240 volts. The lower voltage in the US means that electric kettles would not heat water as quickly as they do in the UK. As a result, they haven't caught on in the US.

Mr. Reid gives this example:

To raise the temperature of one litre of water from 15°C to boiling at 100°C requires a little bit over 355 kilojoules of energy. An “average” kettle in the UK runs at about 2800 W and in the US at about 1500 W; if we assume that both kettles are 100% efficient† than a UK kettle supplying 2800 joules per second will take 127 seconds to boil and a US kettle supplying 1500 J/s will take 237 seconds, more than a minute and a half longer.

He concludes: "This is such a problem that many households in the US still use an old-fashioned stove-top kettle."

I'm not the only American who has wondered about our lack of electric kettles. There's an entire Reddit thread devoted to it.

One British person living in the US cited the voltage explanation but also wrote that "the culture for it isn't there," perhaps meaning that Americans drink less tea and aren't as fussed about how fast water gets boiled.