09 February 2014

A Smarter Kettle?

The humble kettle is found in almost every kitchen, and although there are a variety of shapes and sizes available, they basically perform the very simple function: boiling water safely.

Simple(ish) physics dictates how much energy is required to boil the water, so one might assume there is no room for design improvements in the way we use kettles.  However, maybe there are not just incremental improvements to design, but also some more radical approaches...

These are the incremental design considerations features all kettles could have:
  • Durable design.  Kettles go through a lot in their lives and although a cheap kettle might save a few pounds up-front, it can be a false economy for both the purchaser and the environment, if it has to be discarded after a few months and a new one purchased.   Could a manufacturer design a kettle with a five year, or even lifetime, warranty?
  • Low minimum fill.  Plenty of people only want to boil enough water for one cup/mug.  Let's make that possible, and make it very, very clear what that level is.  Of course, people have different sized cups and mugs, so why not make the markers user-adjustable, one for that favourite mug, another for the family tea-pot, etc.
  • Variable temperature setting. You don't always need boiling water, so why waste energy boiling it unnecessarily? A lot of herbal teas and cold/flu remedies work with water at 90°C, so let's make that an option
A kettle with a varying temperature setting
My Bosch TWK86103GB - variable temperature setting
  • Switch off when it's boiled.  A lot of kettles continue to boil the water for several seconds after the water has reached boiling point, unnecessarily
So far, so good.  But is buying a kettle, using it for 3-4 years, then throwing it out the right answer? Possibly not...

Rather than buying a kettle from a retailer, could the manufacturer offer a service direct to its consumers?  Beyond that, could they help build brand affinity even further?

Let's look at what a 50p a month (£6 per year) kettle service look like...
  • You order a kettle direct from the manufacturer's website (with all the features outlined above).  It arrives in some reusable and foldable packaging, you're asked to keep
  • You use your new kettle as normal
  • If there's a problem, you send the kettle back to the manufacturer (freepost), and once validated, then send back a replacement/refurbished one; this offer is available for life, even if you move home
  • The manufactuer is heavily incentivised to make their kettle last as long as possible, easy to upgrade/repair and minimise the use of raw materials in its production

And how about a £1 per month (£12 per year) kettle service?  Everything above, plus:

How about the kettle has an in-built USB stick*, and the ability to record how much water is put in the kettle when filling it, then compares to how much is actually used (poured)?  Uploading the data to the manufacturer's website allows a graphical display of how much water was boiled unnecessarily (and its approximate cost) - perhaps contrasting against others in a league table.  And perhaps this could also provide additional diagnostic information such as a recommendation for when to descale the kettle for optimum performance.  This data gives the manufacturer valuable insight into how their products are used for future innovation...

*Assumption is that a realtime Zigbee/wi-fi enabled kettle might be considered an invasion of privacy

What have we achieved with the ideas above?
  • You and I still get to have a cup of tea whenever we want
  • We find intuitive aspects of the product design which mean we only use the amount of water we need... and to the maximum temperature required
  • Manufacturers are incentivised to make the kettles last as long as possible
  • We, and the manufacturer, learn a little more about how we use our kettles

I'd be really interested to hear your thoughts, so please add your comments below.  If you've got any links for innovative approaches to kettles, please share these too.


  1. Great article Richard, thanks. Having recently been looking at new kettles, I've noted that several of them are starting to include a "keep warm" function. From a sustainability perspective, this appears to be a negative thing (IMHO) - the user isn't incentivised to boil the kettle "just in time", but can leave it keeping warm. I don't know how much energy is actually used in doing this though!?

  2. I think that the leasing model requires additional drivers before it can become mainstream. Think back 30-40 years when almost all televisions were leased. It was because the cost to buy a set was prohibitively high compared to earnings. Now, we have low cost, technology for the masses brought about by low cost manufacturing.
    For the example of kettles, for £6 it is possible to buy a kettle that meets the basic requirement to boil water. I know because I own one, having previously bought the £40 versions that only seemed to last 3 years. The £6 kettle may not look amazing, but if it lasts one year then I’ve broke even according to the 50p per month lease model. That’s the free market economy we live in.
    Now if that £6 kettle had an ‘environmental purchase tax’ to artificially raise the purchase price to £36, then I would be very inclined to choose the lease model!

  3. One problem with only boiling the exact amount of water you need is that the gritty scale that always ends up in the bottom of the kettle gets poured out into your tea. Closely linked to this is that a recently boiled kettle has enough residual heat in the base to completely dry out any remaining water, compounding the scaling problem. The only way around this is to avoid ever emptying it - which is one reason people overfill their kettles (myself included - I live in a very hard water area where a freshly descaled kettle gets crusty in a week).

    Perhaps, though, if kettles could be fitted with much more effective filters on the spout, at least the first of these problems could be avoided?

  4. Thanks for your comments everyone, I'll take each one separately:

    Anon - I think the 'keep warm' function has two challenges - one obvious, and one less so. The obvious one is that the kettle keeps water boiled unnecessary, when nobody wants boiling/boiled water. The second is that I think it would encourage people to keep the kettle filled, always leaving enough for the next use/person. Constantly keeping more water than required at a higher temperature than required can't be the right answer...

    Martyn - thanks for your comment. You are right that the cost of a cheap kettle is so low, it's going to be hard to make a lease model profitable. An environmental tax would help of course, as it may be many yeas before the raw material extraction cost forces the cost price of cheap kettles up. I also remember 'Radio Rentals' in the High Street, and will be blogging about that in the future.

    Mike - a great point that may mean people are boiling more water than they really need. Better filters in the kettle, "time to descale" warnings, or even a kettle coming with some sort of external 'tea strainer' type filter could all help maybe?

    Offline, I have also had a comment that if there was a way to remind the user that the kettle has recently boiled may help someone unnecessarily reboiling it, after they've perhaps been distracted for a few minutes