WattsonWatts in a name?  Well, that must have something to do with electricity, doesn’t it? 

It’s pretty elementary as Sherlock Holmes would say to his inquisitive offsider, Watson.


I love the name that DIY Kyoto has given to this energy monitoring device. 

Do It Yourself Kyoto is also pretty indicative of the type of company behind this. 

So let’s see what the Wattson is capable of telling us apart from all the pretty colours and numbers.




If you have been reading DigitalReviews.net from way back you will know that we have a passion for being able to monitor our energy use.  See for instance the review we did on the Kill-a-Watt Energy Monitor a few years ago.  This device was conceived to basically to monitor individual appliances.  The Wattson however will monitor your total electricity use and displays it on a cool looking device.


And this is probably the whole point of the Wattson: the device is so good-looking with its enigmatic glowing colours that emanate from it and with big red numbers displayed on the top that it has to be a talking point in your family and with friends that visit you.  Which directs you to the energy consumption at that very moment. Do you really need to have all these lights switched on?  Particularly when the Wattson is glowing red-hot, indicating pretty heavy electricity consumption, see what you can switch off.


Mind you, the Wattson itself does use some electricity as you may suspect.  Admittedly, it’s only some 5 Watts but still, you would not want it wind powered, would you? The other, not so tree-hugging aspect, is that the wireless box that clips on to the main electricity cable, also uses electricity in the form of four AA batteries.  They last only six months on average even though you can set the device to transmit data less frequently so that you can stretch out this time to about 12 months.  I just wonder if it would have been possible to use induction to power the wireless box? It may not generate enough power as it has to transmit data over some 100 meters.  If there are any obstacles, like walls, in between than this is may be reduced to 30 meters.






It’s pretty straightforward and relatively simple to install a Wattson. The manual (on recycled paper, of course) is a pleasure to read. Then it’s a matter of clipping something around one of the main electricity cables in your meter box…


That is, if you can see one.  In my case the electricity box on the house was so neatly organised with all the main cables tucked away behind a panel, that I was not game to discover any further.  However, we also have a main panel located about 60 m from the house.  You can see from the picture that it was not quite that easy.  I had to gingerly grapple the only cable that I could see which had a bit of slack. 


There is another complication with the type of setup that I have here at home.  We have a so-called Smartmeter which has different tariffs according to the time of day. The idea behind this Smartmeter is of course to encourage electricity consumption outside of the peak times which the company stimulated by lower tariffs.  Well, that lasted a few years until those tariffs have been jacked up as well…


So the Wattson will not correctly indicate the real cost as we have four different tariffs instead of one!  However, you can still get a fairly accurate reading of the total kilowatts that are being consumed.  I have always been doing that myself anyway on the first of every month.  I have an historical record going back many years as we have to read the meters ourselves and send the readings to the electricity company every couple of months.


The Wattson will help you do this monitoring for up to 60 days through the Holmes software which you can use to tweak the numbers. The software can be downloaded for the DIYKyoto site.  If using too much electricity is an (ecological) crime, then Holmes is the ideal partner in crime detection!


Using and Reducing


So once the wireless transmitter has been installed in the meter box it’s time to plug-in the main display unit.  There’s only one button on the device and that is a toggle switch to display both the colours and the numbers, numbers or colours only and a night mode.  Cool blue is good, hot red is bad for your wallet.  I was surprised to see that with only my desktop plugged in (sure, it’s a big one) the unit already displayed an indigo colour.


Initially I had the unit installed in the kitchen, being closest to the wireless transmitter.  Later on I unplugged it and walked around the house with it to see how much range I could get out of it.  Yes, it made it to the lounge and to my office but at other locations I got the message Out of Range on the display.  It’s good to see that this unit also has rechargeable batteries even though they last only a few hours or so.  It is handy to take it with you to different locations in the house to see the immediate effect on the unit as you switch on the big fellas like the heaters, dishwashers and washing machines.


The Wattson displays the cost in British pounds but the currency can be changed with the software.  I think that it’s an effective deterrent to using lots of electricity when the Wattson displays the total cost of what you are using currently if you left it on for a whole year!


And very interesting is also that the Wattson makes use of tilt technology.  By tilting the Wattson the unit of measurement changes from Watts to pounds per year (this is currently set at 30 pence per kilowatt hour)






The Wattson from DIY Kyoto costs about £150 which translates into just under $300 US.  That’s not inexpensive and there are a few cheaper alternatives on the market, particularly in the UK.  The Wattson though is the Rolls-Royce where you do pay for a prestigious display. Personally, I like it very much and not just because of its good looks.  Saving electricity is a family affair: I cannot be the policeman to switch off the devices in the house after everyone else.  Everybody needs to be convinced about it and the Wattson makes it painfully clear to everybody in the lounge when things are left switched on unnecessarily.  There is the danger that, for instance in winter time when a lot of heating is required, people get used to seeing red…


The Wattson can also make it very clear that something has been left on inadvertently and as such can really make a difference in your wallet.  Highly recommended.


Technical Specifications


    * Able to measure single, twin and three phase systems (extra clips required).

    * 12.5KW max per phase.

    * 1W resolution of display.

    * 14 segment LED digital display.

    * RGB LED full colour ambient light.

    * 32kb non-volatile EEPROM internal memory

    * 433Mhz transmitter / receiver, approx. 30m range.

    * 3 – 20 second refresh rate, user changeable.

    * 3 – 6 month battery life (Sensor).

    * USB 1.0 and 2.0 compatible.

    * USB-A to USB mini-A cable supplied.

    * Currency changeable: £. $, €.

    * Casings made from Polycarbonate, Polypropelene and ABS.

    * Display: 105mm X 170mm x 55mm.

    * Transmitter: 110mm x 84 mm x 26 mm.

    * Software Mac and PC compatible.  World from