Have you ever wondered how just one Smappee device manages to monitor different appliances from one single spot (i.e., where the power cable enters your fuse box)? Think Shazam, the app that identifies songs? Smappee is the Shazam for electricity. Find out how it works.

Exact, real-time total energy consumption

Immediately after it has been connected to your fuse box, the Smappee monitor will start listening to the flow of energy running through your house. From the very beginning, the app will show you a real-time overview of your energy consumption. Go ahead and give it a try: switch on the kettle to make yourself a nice cup of tea. You’ll see the grey bubble getting bigger. A notification will pop up to tell you exactly how much energy this device is using. But that’s not all; Smappee takes it further.

Appliance recognition

Smappee’s appliance recognition is based on a groundbreaking technology called NILM (Non-Intrusive Load Monitoring). How does it work? Every appliance has a different way of using the electric current. You could say they each push out their own electrical signature. Every time an appliance is switched on and off, Smappee hears these electrical signatures and recognizes the actions as an ‘event’. After a while, Smappee will start recognizing an event’s electrical signature and will assign it to the according appliance. But matching the power changes with the right appliance takes time. The word speaks for itself: appliance recognition.

The NILM technique can be compared with the Shazam-principle. Imagine you’re in a crowded bar in which the DJ set, radio and television are playing all at the same time, in addition to the crowd’s chatting, laughing and singing. Your Shazam app will have difficulties recognizing that one specific song you want to know. Now that’s the titan work Smappee is dealing with in your home too: it hears a whole concert of lights, fridges, chargers, pumps, etc. singing their own electric melody simultaneously. From that concert of different voices, Smappee abstracts the different melodies (appliances). For example, a lamp of 60 Watt sounds different from a fridge that is also using 60 watt. That’s how Smappee can distinguish them from one another, reporting them as ‘Appliance 1’ and ‘Appliance 2’. Nevertheless, because Smappee works like Shazam, it also faces the following few limitations:

  • Just like two equal instruments are hard to distinguish, Smappee has difficulties distinguishing appliances with comparable electrical signatures (eg. appliances with a heating element, like toasters, water boilers or cooker hobs).

  • One song containing different melodies (ever heard ‘Les lacs du Connemara’?) can be quite confusing and might not be considered one ‘whole’. The same way, appliances with an ambiguous pattern due to the variable capacity (like televisions with ambilight, heatpumps ...) might be recognized as different appliances.

  • Smappee also has a hard time trying to identify the so-called ‘silent’ appliances (using less than 30 Watt), as these are drowned out by the louder ones. For example, for a Smappee, recognizing a LED lamp is just as hard as it is for you to hear your smartphone ringing when you’re at a hard rock concert.

Standby power consumption

Some electrical signatures seem to never be switched off and therefore never report on/off events. Smappee will consider this a constant use of electricity and categorize it as always-on power. In the blue bubble in your app, you can see the average always-on power of the past 24 hours. The reason why Smappee knows how much Watt your always-on power consumption is, is also the reason why Smappee can’t tell you which appliances are a part of it: as they don’t get turned on and off that often, they don’t induce any events. Appliance detection is event-based, so if Smappee can’t hear any events, it can’t find those devices.

Ever-improving technology

While we’re passionately perfectioning our groundbreaking appliance recognition technology, there’s no doubt you can already benefit from the positive impact the Smappee monitoring system has on your energy savings. Here are some quite exclusive advantages that already put you ahead of the game:

  • No matter what appliances are or are not added to your appliance list, the reported real-time total energy consumption is impeccable.

  • Tracking down energy guzzlers becomes child’s play.

  • You’re aware of your always-on power consumption.

  • While others still have to deal with an unclear energy bill (on a yearly basis!), you get an itemized bill, showing you how much your most important devices consume per day, year or month and how much this is costing you.

  • You can control your appliances remotely thanks to the compatibility with Comfort Plugs™, IFTTT and Stringify.

Excited as our developers are to make our appliance detection a perfect fit for your needs, all feedback is more than welcome. Any reported issues are actively taken into account during our non-stop improvement process. As such, we have recently launched an improved appliance recognition technology called NILM 2.0. This technology can now significantly reduce the confusion a Smappee monitor might experience. Also, some main appliances like your freezer or fridge are now auto-labelled.


Still have questions? You’ll find all the info you’re looking for on our support page.