Over the last few decade we've seen a few major pushes around lowering our energy consumption. We got rid of our old incandescent lightbulbs, so inefficient you could give yourself a burn just changing one. Washing machines now get marked on their power use. And the power-sucking standby modes of TVs and kitchen appliances are now, mostly, a thing of the past.
We tend to leave home tech ticking away in the background 24 hours a day, all year long, though. While all these gadgets are designed to use as little power as possible, how much will they actually burn in a year?
Read this: Why 2018 is the year of the smart kitchen
With the help of a power meter, we’ve tested some of the most popular smart home tech to see how much energy they use, and how much it’ll cost you to keep them running over a year. The short version? You're unlikely to notice the increase in your energy bills.
A quick note on jargon
First, let’s deal with a few terms.
We’re going to give you the wattage of each product. However, to square this with the bill you get from your energy supplier we also need to deal with the kilowatt hour. This is what you get when you divide the wattage figure by 1000. It’s a measure of energy use over time.
Check your most recent energy bill or sign into your supplier online to find out how much you pay per kWh. To calculate our cost sums, we’ve used a figure of 13p per kWh in the UK, and 12 cents per kWh for our US figures.
Calculating the cost of a smart home
No lone smart home product uses much energy, as you'll see when you dig into the calculations below. But what if we put together a little simulated smart home? Let’s say one with an Amazon Echo, two Echo Dots and a Sonos Play:1. Plus four Philips Hue smart bulbs that’ll be used four hours a day at maximum brightness.
Throw in a Logi Circle 2 smart security camera for good measure. How much would that cost in a year?
A rough calculation says the Echo uses around 26kWh, the Dots about 21.9kWh a piece. The Sonos? 33kWh based on 10 hours of listening a month. The Hue bulbs will use around 9kWh each. And the Logi Circle 13kWh.
Add that all up and you get 151.8kWh. And on the average UK power deal, that equates to around $18 worth of power. That’s not too much for a year’s worth of music, lighting, security and, if you really get into Alexa, conversation, right?
How much power do always-on, always-listening smart speakers like the Echo use? We tested out the original Echo and an Echo Dot to find out – devices like the Google Home will likely have a similar consumption.
- 3W standby with mics on
- 6.6W playing Spotify at max volume
- 4W playing the Golden Ticket skill
Year of standby at 13p/12c per kWh: $3.15
Amazon’s own estimates of 3W for the Echo’s power consumption are pretty much perfect. It uses 3W when just hanging around listening out for the Alexa wake word.
Use a Skill like the Golden Ticket movie trivia game and that only bumps up consumption to 4W. Play Spotify at max volume and the average power use is around 6.6W.
The Google Home claims to use just 2W in standby, although this will only save you about $1 over a year. However, if your house is full of Echos, bear in mind they are constantly sipping juice at about the rate of a lower-power LED lightbulb.
Amazon Echo Dot
- 1.7-3W standby
- 3W Spotify at max volume
Year of standby: $3.15
You might expect the Echo Dot, as a smaller unit, to use a lot less power than the full-size Echo.
In standby we found it seems to meander between about 1.7W and 3W power drain. Given at this point it’s doing exactly what the larger Echo does, we’re actually surprised to see those consumption dips.
Play music through the Echo Dot using Spotify and it stays around the 3W mark. This is because the puck has a pretty weak amplifier and speaker. However, it’s a little strange to think it’s using a similar amount of power whether it’s actively doing something or not.
- 3.5-4W standby
- 5.6W 25% volume
- 11.2W at 80% volume
Year of use on standby: $4.24
100 hours at 80% volume: 14p/13c
We didn't have a Sonos One for this particular test, but it’s likely to have similar power use to the Sonos Play:1.
It uses 3.5-4W in standby, which is relatively high if you only use your Sonos every now and then. Use it every day? No problem, as it shouldn’t cost you more than £4.60/$4.24 a year.
We’d argue the Sonos Play:1 can be used as a main music source if you’re not a sound obsessive. It sounds great to us. Even at 80 per cent volume, it only uses 11.2W. That at a volume that’ll make your neighbours dislike you.
Streaming sticks and boxes
You might be aware of how much power your TV guzzles up, but what about the extra boxes and streaming sticks that get you smart TV apps and games? Again, these tend to be low power but if you've got more than one add-on, it could start to add up.
Now TV Smart Stick
- 2.1W on interface
- 2.2W playing iPlayer
Year of standby: $2.21
The Now TV Smart Stick is a low-power streamer that lets you ask for movies and TV programmes using a fancy new voice remote. However, it’s still one of the lowest-powered smart TV solutions because it runs the basic Roku OS software rather than Android. And only needs a basic processor as a result.
We barely noticed any difference whether the Now TV stick was sitting there idling or streaming video from iPlayer. Sat on the interface it uses 2.1W. Streaming a show it uses 2.2W.
That’s lower than the idle power consumption of the Amazon Echo. However, don’t forget your TV will use loads more power to light up its screen. Our 55in Panasonic plasma TV uses 160W-300W, for example.
Nvidia Shield TV
- 1.5W standby
- 3W on interface
- 4-5W playing BBC iPlayer
- 7.6W playing Real Racing
Year of standby: $1.60
100 hours of Real Racing: 9p/9c
The Nvidia Shield TV is one of the most powerful smart TV boxes and it runs Android TV, giving you access to the Google Assistant AI
Play a game like Real Racing and you’ll see the power use reach highs of around 7.6W. Just browsing around the interface just uses 3W, though.
And, perhaps because this is designed as a TV set top box from the ground up, the standby mode is particularly power-frugal. A standby that consumes just 1.5W of power beats just about all rivals.
With smart lights, standby seems to be negligible so we decided to test out Hue bulbs with varying brightnesses and colours to see the difference in power and energy costs.
Philip Hue bulb
- 6.1W cool white max brightness
- 2.5W red max brightness
- 5.1W green max brightness
- 3.5W blue max brighness
- 1.7W warm white 50% brightness
Year of 24/7 use at max brightness: $6.41
Two hours a day for a year: 57p/53c
Philips Hue made smart lights mainstream. Its bulbs are also one of the very best bits of home tech to show off – “Look at my pink-lit living room” and so on.
We tried one of its colour bulbs plugged into a short plug-mounted fixture, so we could use our electricity meter. While it registers zero power when simply plugged in (Philips says standby is 0.2W max), the power consumption in use varies quite a bit depending on the colour.
Cool blueish-white uses the most, at 6.1W with the brightness maxed. Standard warm white uses just 1.7W at 50 per cent brightness. You could leave that on all year and it’d barely add to your electricity bill.
Philips Hue Bridge
Year of standby: $1.60
The Philips Hue Bridge is what communicates between your phone and your Hue lightbulbs. The Bridge uses very little power, with a consistent draw of 1.5W. Even when it’s left on all day and night for a year, it’ll only cost around $1.60 to power.
This is one of the lower-cost smart devices to keep operational, although of course the real power draw comes from the bulbs themselves.
LIFX+ 1100 Lumen
- Full power White - 11.7W
- Full power blue - 8.1W
- Full power green - 5.1W
- Full power red - 7.6W
- 50pc power white - 4.5W
- Standby - 0.3W
Year of use at max brightness - $12.29
Two hours a day for a year cost - $1.34
LIFX bulbs are a little different to Philips Hue ones as all the electronics are built into the bulb, no need for a hub. Our initial worry was that they would suck up a small amount of juice 24/7, which would add up over a year if you have a bunch of LIFX bulbs.
However, on standby each only uses around 0.3W, often as little as 0.2W: just a third to a fifth the consumption of a Hue Bridge.
The big LIFX+ bulb appears to use significantly more power than a Hue bulb when lit. But that’s because it’s brighter too. It’s rated at 1100 lumen, and is better at lighting larger rooms than a Hue bulb.
There is a real power difference within the range because even the smaller LIFX Mini (800 Lumen) uses a little more power than a Hue bulb. However, unless the lights are going to be on all day long, the cost difference over a year is fairly small.
LIFX Mini 800 Lumen
- Full power White - 8.6W
- Full power blue - 5.6W
- Full power green - 5.1W
- Full power red - 5.1W
- 50pc power white - 3.0W
- Standby - 0.3W
Year of use at max brightness - $9.04
Two hours a day for a year cost - $1.07
Smart security cameras
Security camera power usage will vary depending on whether or not they're actually recording and if they include features like motion sensing and two way talk.
Logi Circle 2
- 1.6W standby monitoring
- 1.9W recording
Year of 24/7 use: $1.68
The Logi Circle 2 is the least power-hungry security camera we’ve tested for power consumption. It uses just 1.6W when monitoring your house for movement, which creeps up to a max of about 1.9W when you use the Live View feature and start messing around, talking through the camera. This will cost you around $1.68 to run for a year. Not much.
- 2.2W standby motion sensing
- 2.5W Live view
Year of use: $2.31
The Hive Camera doesn’t use cloud storage, so if someone breaks in and nabs the microSD card, you’re stuffed. However, it does have essentials like live streaming to your phone. When simply monitoring it uses 2.2W of power, putting it higher than the Logi option in terms of energy use. This maxes out at around 2.5W during moments when you use the live view.
Wi-Fi Mesh Systems
If you're moving into intermediate smart home owner territory with lots of devices in different rooms, you might want to invest in a Wi-Fi system. The Netgear that we tested, though, actually had the highest power consumption of all the products we tested with the power meter.
- 6.6W in use
- Similar use with satellites
Year of use: $6.93
Wi-Fi issues in homes can be a real headache. The Netgear Orbi is one system that can fix all that, acting as a router and a mesh network to flood your home with signal.
It uses a fair bit more power than some smart devices when doing so, though, using around 6.6W of power in general use, per unit. Use an Orbi and two satellites and you’re looking at power consumption of up to $21 a year, although we’ve had times where we’d pay that several times over just to get good Wi-Fi signal.