This Monitor Shows You Exactly How Much Power Each Of Your Gadgets Is Sucking From The Grid

Smapee lets you into the deep, dark secrets of your electric bill. Once you know what’s happening, your life–and energy use–will never be the same.

How much energy does your refrigerator use? Or your hair dryer, or toaster? Until recently, the only way to find out was to plug each appliance into a usage meter, something that only the most energy-obsessed actually take the time to do. But now a single device can tell you exactly how much power items in your house are draining at any given time.


“If you give real-time feedback. People start to understand that something’s consuming so much power, people start reducing energy use,” says Stefan Grosjean, founder and CEO of Smappee, the Belgium-based startup that launched the device in the U.S. today.

The small box works by recognizing the unique “electronic signature” of everything in your home. When your laptop sucks power from the wall, it creates a different signal than your fridge or your lights or your electric car. As the sensor measures what’s running, it shows you on an app.

It can send alerts, so if you accidentally leave an iron running, you can come home and turn it off (it can also be paired with smart plugs that can be controlled remotely, so you could actually also turn the iron off from your office or the airport). “In my case, if the garage door opens, Smappee tells me so I know that the kids got home safely every afternoon,” Grosjean says. “It gives additional capabilities; it’s not just measuring energy consumption.”

It also works with IFTTT, a web service that allows anyone to design their own simple commands. For example, you could tell it to wake you up when your coffeemaker is done making you coffee each morning. Grosjean has his system hooked up to an LED light that turns red when he’s using too much power, and green when his solar panels are producing excess energy.

The device measures solar panel output through a second sensor. Since smart meters often only show net production (if your solar panels produced 1,000 watts and you used 1,000 watts, it will say you’ve used “zero” energy), Smappee provides a way to track energy more accurately–something they say will be especially useful when people start storing solar energy in their homes. People can track exactly how much energy they’re making, and using, and better calibrate use.

By providing detailed data, the device also changes how utility companies can work with consumers to reduce energy. “Unlike everyone else, who can usually only provide pretty generic tips that don’t really engage people, we can provide very specific tips,” says Richard Morgan, head of business development at Smappee. “Because we have the visibility, we can say things like, ‘Did you know your fridge is using three times more than the national average?'”


Before starting Smappee, the company’s founders spent two decades helping corporations measure energy use, and realized that the only way anyone can make significant changes is to understand the details of how energy is used. A single number on a monthly bill doesn’t help much, but when companies start sub-metering, they can reduce energy use by as much as 40%. The founders wanted to bring the same capability to homes.

“Our challenge was that we wanted to have a cheap, single metering device, like your utility meter,” Grosjean says. “This was the holy grail. We worked a long time on that, and we’re the first product on the market offering it.”

About the author

Adele Peters is a staff writer at Fast Company who focuses on solutions to some of the world's largest problems, from climate change to homelessness. Previously, she worked with GOOD, BioLite, and the Sustainable Products and Solutions program at UC Berkeley.