HomeKit Devices: Eve Energy Tells You How Much Electricity an Appliance Is Using

 Eve Energy Tells You How Much Electricity an Appliance Is Using

I'm enjoying making my home smarter via Apple HomeKit-compatible devices. So far I've written about iHome's SmartPlug ($39.99), which lets you set up an on/off schedule as well as control an appliance remotely, and Elgato's Eve Room ($79.95), which lets you monitor volatile organic compounds in the air in a room, as well as humidity and temperature. In this post I'll cover a handy gadget from Elgato that lets you monitor how much electricity an appliance is using: Eve Energy ($49.95). Elgato has also given me Eve Weather and Eve Door & Window and I'll cover those HomeKit devices in future posts.

Eve Energy

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You probably would like to get more of a handle on your electricity costs, as well as reduce your carbon footprint. Eve Energy can help. It's a small HomeKit device about two inches square and an inch deep that you plug into an outlet. And then you plug your appliance into Eve Energy.

I was curious to know how much electricity my HDTV uses, so that's what I plugged in first. But I also plan to test my computer, Apple TV, refrigerator, and more. I've often seen it suggested that one should turn off power to an HDTV rather than simply turning the set itself off. That's because it draws power even while it's off. Essentially, it's in a sleep mode, similar to a computer. I wondered how much power that took and whether it was really an issue.

I found out that my HDTV is drawing 4 watts of power while off. That's not a lot, but it's more than other HDTVs, which I've read draw less than 1 watt when turned off. Usage jumps up to around 60 watts when my TV is on. The "At a Glance" screen for my Living Room shows current usage and total consumption.

Total monthly energy bill for my HDTV: less than $1

I've been monitoring my TV for a week now, and total consumption is at 1.26 kWh (kilowatt hours).  A kWh is a the energy equivalent to one kilowatt (1 kW) of power expended for one hour.

How much does 1.26 kWh cost me on my electric bill? Typically 1 kWh costs around 10–15¢. So that means that I'm spending much less than $1 per month on electricity for my TV.  I don't often have it on though, mainly for about 15–30 minutes early in the morning.

The upshot for me is this: At less than $1 per month, I don't feel like I'm wasting money or doing that much damage to the environment by leaving my HDTV in sleep mode rather than unplugging it.

Next, I'm going to test my computer, because I always put it to sleep rather than shutting it down. If I find that it's still drawing quite a lot of power during the night, then I'll start shutting it down overnight.

The Eve app offers detailed views of total consumption for four different periods: hour, day, week, and month.

Using HomeKit to schedule Eve Energy

The Eve app's HomeKit features are sophisticated and fairly easy to use. You can set schedules for your devices, and have them all operating in concert. I realized that I could use what HomeKit calls "Timers" so that Eve Energy would automatically turn off at night and turn on in the morning. Even though my HDTV in sleep mode is using very little energy, I can automate shutting it down at night by scheduling Eve Energy. I used the Eve app's Timer feature so that Eve Energy shuts off at 9 p.m. every night and turns on at 5 a.m. every morning.

This is the beauty of HomeKit. You can create Scenes, identify rooms, identify the HomeKit-compatible devices in those rooms, name the specific functions, and then use Siri to invoke those functions. It all works together.

I can also use Siri to turn my HDTV off and on via Eve Energy.


  • Easy-to-use HomeKit device tells you exactly how much power an appliance is using, showing the current rate of consumption as well as total consumption.


  • I can use Siri to turn Eve Energy on and off, but not to get any information about power consumption.

Final Verdict

This is a useful gadget if you want to track power consumption. Plus, the HomeKit features let  you set on/off schedules. 

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Jim Karpen holds a Ph.D. in literature and writing, and has a love of gizmos. His doctoral dissertation focused on the revolutionary consequences of digital technologies and anticipated some of the developments taking place in the industry today. Jim has been writing about the Internet and technology since 1994 and has been using Apple's visionary products for decades.