Why You Can Trust CNET Sense review: Sense knows how much electricity you're using
The Sense Home Energy Monitor promises to track the output of individual devices, but ultimately falls short.
Editors' note (September 28, 2017): Since publishing this review, Sense has identified 14 new devices: the HVAC, the oven, "unnamed heat 1," the microwave, "unnamed device 1," "unnamed motor 3," "unnamed device 2," "unnamed heat 2," the ice maker, a light, "unnamed heat 3," "unnamed device 3," "unnamed device 4" and a refrigerator. I'll continue to provide updates as it learns more.
The Good
The Bad
The Bottom Line
The $299 Sense Home Energy Monitor (£240 and AU$390 at the current exchange rate) is supposed to bridge the gap between your utility-issued electric meters and detailed usage data. Sense successfully communicated whole-home watts at-a-glance during our testing. It also detected a few of the large appliances in the CNET Smart Home automatically. But like its competitor, Neurio, Sense had trouble identifying certain devices.
Sense's FAQ page says it's working on algorithms to detect more products, so it might get smarter soon. For now, if you're looking for in-depth data about your home energy consumption, this home energy tracker is pretty limited and I wouldn't readily recommend it.
A note on electricity
All of the electricity-dependent products in your home contribute to a total watt (W) or kilowatt-hour (kWh) reading. (Note: one kWh is 1,000W.) At any given time, you should be able to see real-time energy stats on your home's electric meter. This info is then used by your local electric company to calculate the amount you owe.
But there's a problem. Meters, especially traditional non-digital units, are difficult to read -- and they only give you an overview of your consumption, rather than itemized watt or kilowatt-hour readouts of individual devices. That means you're out of luck if you want to better understand why last month's bill was so high.
Ideally, Sense should help you identify individual devices and figure out how to change your usage patterns. That's when you'll start to see savings and reduced strain on the electric grid.
Getting started with Sense
The smallish rectangular Sense attaches to the main switch inside your breaker panel and relies on two sensors to detect unique device "signatures." While it took two electricians only 10 minutes to install Sense, this is not a do-it-yourself project. The installation requires the removal of the breaker panel and there are all sorts of potential shock hazards involved.
Sense is compatible with recessed and wall-mounted electric panels. It will work with more than one panel if Sense is installed in the main electrical panel and the additional panels are subpanels. Not sure if it will work in your home? Check out the Sense FAQ for more info before you buy.
Sense CEO Mike Phillips offered some insight on its device detection functionality via email:
"In terms of what Sense can detect and what users can expect, this varies a lot by home, based on the signatures of your devices and how similar their power profile is to other devices in your home. We model each home's devices individually. In most homes, Sense does a good job detecting core devices such as microwaves, refrigerators, garage door openers, air conditioners, garbage disposals, dryers, etc. It takes time for Sense to detect these devices because it needs to see enough data. For example, we typically detect the refrigerator first since this cycles on and off continuously, so we see many occurrences."
According to Sense, products generating more energy are easier to single out, but it is possible for it to identify devices with a low 5W to 10W output.
That's where Sense differentiates itself from Neurio, which wasn't able to detect any appliances under 400W. Sense attributes its ability to detect low-wattage devices to the 4 million readings it takes per second to identify unique patterns. Theoretically, this should give Sense an edge over the competition.
Using Sense
After Sense is installed by a qualified professional, the device should chime to let you know the configuration was successful. Download the related Android or iPhone app and follow the instructions to connect it to your local Wi-Fi network. Sense doesn't currently have a web interface, so you're limited to viewing your energy stats on your mobile device.
Inside the Sense iOS app.
You can view a graph or a bubble chart of the wattage output in your home 24/7 (assuming you have a solid Wi-Fi connection). Walk around your house and flip light switches on an off, cook dinner, run the dishwasher and see the visual representations change accordingly in the app.
You'll also get emails when Sense detects new devices, but it doesn't always happen quickly. Sense was installed on February 16. On March 3 and 14, I got emails saying Sense had "learned new devices."
So far, it has detected the dryer, two fridges and two "unnamed motors." Everything else currently lives in either the "Always On" or "Unnamed" device label. After more than a month of testing, I would have expected it to pick up on more appliances. Sense told me its ability to detect products can be slower if the Wi-Fi signal isn't strong. Our connection at the CNET Smart Home goes in and out. I just checked its speed and got 6.72 Mbps for download speed and 0.90 Mbps for upload speed. Not terrible, but not great.
Unfortunately, you can't really "train" your Sense device yourself. Instead, you have to wait for it to be certain it has identified a microwave or an air conditioner before it moves it from the "unknown" bubble to a specific label. Since you can't edit this information yourself, you're left waiting for Sense to catch up. However, you can edit names of devices Sense identified as "unnamed motors" if you manage figure out what they are. I haven't had any luck with mine yet.
The IFTTT rule I created with Sense worked well, though. Sense is supposed to be able to ID things like garage door openers, so you could create the following IFTTT applet: "If Sense notices the garage door is opening, then turn on my LED bulbs/adjust my thermostat/open my window shades." Since I only had fridges and a dryer to work with my rule made a little less sense: "If Sense notices the dryer turning off, then open the Lutron window shades." Still, the applet worked fine.
Although Sense is supposed to be able to detect devices with lower wattage outputs than Neurio, these two products are fairly similar. Both have decent apps that display real-time energy stats for the whole home. Neurio has a more hands-on approach, allowing you to turn devices on and off and label them accordingly. Sense takes this on for you, but seems to do it fairly slowly (again, this can vary based on the quality of your Wi-Fi connection).
It might also matter that no one actually lives in the CNET Smart Home. We test products here every day, but we aren't using the large appliances and smaller electronic devices the way someone living here would use them. Even so, I think five weeks should be enough time for Sense to identify the microwave, the HVAC unit and other electrical devices we use here day to day.
The verdict
Sense costs $50 more than Neurio, but it hasn't managed to differentiate itself in any significant way over five weeks of testing. Usage stats are fairly limited and you don't have much control over how quickly it detects your appliances. It's a useful tool for real-time energy stats -- the house is currently using 576W of power, for instance.
I'm just not sold on spending $299 (plus the cost of an electrician) for a device that has only successfully identified two fridges and a dryer in over a month. I'd hold off to see how we like the competitor Curb and the Indiegogo-funded energy monitor Ecoisme.