Energy saving kettles

Ways to save energy on your next cup of tea

If you’re looking for energy saving kettles, you probably don’t need to look much farther than your own kitchen. Some simple common sense will save you a lot more energy when boiling your water, than trying to track down a kettle that’s more energy efficient.

Consider electric kettles. Remember that an electric heating element is 100% efficient at converting electrical energy to heat. You aren’t going to find one kettle with a heating element that’s more efficient than another. There are of course a couple of features that can help you make more efficient use of a kettle. Cheaper kettles, for example, sometimes lack an automatic shutoff, which means that if you get sidetracked, your water keeps on boiling until the kettle boils dry (and possibly burns itself out). So a kettle with automatic shutoff will save you energy if you tend to leave the kettle boiling and then wander off.

Here are some of the key things you can do to turn ordinary kettles into energy saving kettles, without rushing off to the store to buy a new one:

Only boil what you need. This is an obvious one: if you’re making a four-cup pot of tea, only put four cups of water in the kettle. There’s no point boiling more water than you need. It will take longer, and it will use more energy. So measure carefully.

Of course, if your kettle doesn’t let you see inside easily, measuring with a measuring cup (or by filling the teapot first, then pouring that into the kettle) may be your only option; since you’re not likely to keep this up forever, buying a kettle where you can clearly see how full it is will help.

Buy the right size kettle. This is really an add-on to boiling only what you need. If you usually only boil a cup or two at a time, get a really small kettle. Larger kettles have a minimum fill level required to cover up the heating element. If that minimum fill level is more than the hot water you need, you’re better off switching to a smaller kettle than always boiling too much water.

The Breville kettle shown at right boils up to eight cups of water, with a minimum one cup setting. For people who tend to make a cup of tea at a time, but occasionally want a full pot, energy saving kettles like this one make more sense than a cheap, conventional kettle where you can’t even tell how much water you’ve added. Also note that this kettle includes five different brewing temperatures so you only heat the water to the level you need. No point boiling water for coffee, if you want it brewed at a lower temperature.

Don’t boil if you don’t have to. For making tea and coffee, you don’t actually need to bring the kettle to a full boil. While it’s one of my perpetual gripes that most restaurants don’t know how to make tea – they brew it with tepid water, which isn’t hot enough to properly steep out the full flavor of the tea – boiling water is too hot for most teas, and for coffee as well. If you could set your kettle so that it only boiled the water to the temperature you need, there would be some savings there. For instance, taking water from 60F to 200F (the temperature recommended for French press coffee) is 140F, while boiling at 212F is an extra 12F more, or an extra 8%. For green teas, meanwhile, the recommended temperature is 175F, so there’s a savings of about 24% on the energy required to heat water for green tea, instead of bringing it to a full boil.

The cordless electric kettle pictured above is a highly rated and relatively inexpensive kettle that does just this – lets you choose the type of temperature for your tea or French press, and then brings the water to that temperature, and beeps when it’s done. It shuts off automatically when done, which is a useful feature – kettles that keep the water hot waste a lot of electricity. On the other hand, if the kettle is in a high use area – say an office kitchen – there is a switch to let you keep the water hot for two hours. The only drawback to this kettle – it’s billed as a feature, but is not a feature in terms of its energy efficiency – is that it keeps the water at the selected temperature for up to half an hour, so that if you start the kettle and get temporarily sidetracked, the water is still ready when you get to it later.

Prewarm the teapot sparingly, and reuse the water: If you are boiling water for tea and you want to prewarm your teapot (a habit my parents insist on, though they never notice when I make their tea without preheating), just pour a half cup of boiling water in the pot, swirl it around for about 10 seconds or so, and pour it back in the kettle. Bring the kettle back to a boil and then make your tea. This way your tea pot is pre-warmed, but you haven’t thrown the hot water used for preheating the teapot down the drain.

Use the hot water right away. Here’s a sin I’m guilty of, as are many others: I start the kettle boiling, then go off and do something else, meaning to get back to the kettle right after it has boiled, and brew my coffee. But I get sidetracked. The kettle boils, then shuts off. Ten minutes later I’m back, and I have to boil the water again to brew my coffee, since the water is no longer hot enough. If you’re heating your house with electricity, this doesn’t matter so much – the heat from the kettle escapes into your house and warms it. But if you heat with a less expensive source like natural gas, or it’s already hot outside, it’s just a waste of energy to bring a kettle to the boil twice, when once will do.

Another thing you can do to ensure you use the hot water right away, is to make sure everything else is ready before the water boils. If you’re making coffee the way I do (hand-pouring a thin trickle of hot water through a cloth filter, as I was tought by coffee connoisseurs in Costa Rica), have the ground coffee in the filter ready to pour, and the decanter waiting under the filter. Don’t wait for the water to boil, then start setting up the coffee-making or tea-making ritual.

Finally, as far as using the hot water quickly goes, if you often tend to forget about the kettle, look for energy saving kettles that let you know when the water has boiled. Old whistling stovetop kettles definitely qualify as energy saving kettles when it comes to forgetful people: it’s pretty hard to leave one of them boiling for very long.

Look for insulated energy saving kettles. If you are like me and you just can’t help getting sidetracked after the kettle has boiled — and especially if you drink a lot of tea or coffee — look for energy saving kettles with an insulated shell. These kettles will keep more of the heat inside the kettle so that the water lasts longer before it needs to be boiled again, or takes less energy to come back to the boil.

For the avid tea drinker, consider an insulated electric kettle such as the Zojirushi series of hybrid water boilers. These are outstanding products that get rave reviews from buyers; they are energy efficient because the water is kept hot in a vacuum flask, and they provide three different temperature settings:

• 208F for ramen noodles and herbal infusions
• 195F for black teas
• 175F for green and white teas

The hottest setting can be used for coffee if you’re brewing it by hand. The Zojirushi is definitely a pricy option but if you want the convenience of instant hot water for your tea you’ll love this line of boilers.

Save the extra hot water. If you do boil too much hot water, use what’s left. Leave it in the kettle – someone else might come along and want to make themselves a cup of tea. Or put the water in a thermos to keep it hot. Or pour it into the sink when you’re doing dishes (naturally, you have the plug in already!). Above all, don’t pour hot water down the drain in winter – you’re just throwing away perfectly good heat.

Use an electric kettle, not a stovetop kettle. An electric kettle will be more efficient than a kettle you put on a stovetop, because much of the heat from a stovetop burner escapes around the sides of the kettle, especially with a natural gas or propane stove. So using an electric kettle is better than using a stove-top kettle on an electric stove, and is probably more energy efficient than using a stove-top kettle on a gas stove as well.

In the case of an induction cooktop, an electric kettle could be less efficient in terms of both price and efficiency. My own experience with an energy saving induction cooktop is that water boils faster on my cooktop than any kettle I’ve seen, and it means one less appliance cluttering up your counterspace. If you cook with fossil gas, you should definitely get an electric kettle. Although people claim gas cooks faster than electric, that’s certainly not been my experience, and even if your electricity comes partially from fossil fuels, your climate impact will be smaller if you boil your water in an electric kettle. Of course, if you switch to a green electricity supplier, you won’t produce any greenhouse gases at all by boiling your electric tea kettle.

Make one pot of tea and keep it hot. No one likes to drink a cold cup of tea or coffee. But what do you do if the pot has gone cold? The easy way out is to boil the kettle again and make a fresh pot, but this can be wasteful. Some other options:

• Reheat the cold cup of tea or coffee in the microwave. Sounds like sacrilege to some connoisseurs, but it does save energy! If you don’t mind it, do it. No one’s watching.
• Make iced tea or coffee with what’s left. Just throw it in the fridge and drink it cold later. Works for me – at least, in the summer!
• Use a thermos for either tea or coffee. Tea can be brewed in a ceramic pot as usual, but as soon as it is brewed, pour the tea (without the tea bags or tea leaves) into a vacuum insulated decanter. This will keep it hot for hours without using any extra energy.

Don’t boil if you don’t need to. If you need hot water but not boiling water, it doesn’t make sense to boil the water and then let it cool down. Similarly, if you boiled the kettle a quarter hour earlier, and some hot water was left in it, you don’t necessarily have to boil that water again — it may already be hot enough for whatever you want to use it for. Some newer energy saving kettles come with temperature controls that let you heat the water to a specified temperature below boiling, while others have a temperature indicator to tell you what the temperature is. If your kettle hot water temperature is at 90C, it’s probably hot enough to make another cup of tea or dissolve a cube of Oxo. No need to boil again.

Some like it hot!

What temperature should you steep your tea?
What temperature should you brew your coffee?

Black tea should be steeped at 195F (90C)
Green/white tea should be steeped at 175F (80C)
Hand-brewed coffee should be brewed at 195-205F (90C-95F).

There’s really not much more to energy saving kettles than this: boil only what you need, use it right away, keep it hot in a thermos without using more energy, and be at hand and at the ready when the kettle does boil. If you strive to do this, then all the kettles you come across will be energy saving kettles. And if you’re looking for a new energy saving kettle, just buy one that’s the right size, is electric, has an automatic shutoff, and, if you get easily sidetracked, reminds you loudly when the water has boiled!

A word about coffee makers

You can make your coffee as I do, by pouring near-boiling water into a cloth sack filled with ground coffee. That’s how they do it in Costa Rica, where I lived for a year, and it does make delicious coffee. It’s reasonably efficient as long as you make sure, as with tea, to only boil the right amount of water.

But it may be more energy efficient to use a coffee maker, especially one with a thermal flask that keeps the brewed coffee warm without requiring a heating plate. Another alternative is to use a small coffee maker if you typically only drink a cup or two at a time. People often brew a huge pot of coffee, leave it on the warming plate, and then wind up throwing most of it out because it’s been cooked to death.