Sense home energy monitor - not recommended (yet)

Published on 28 Jun, 2019 by Michael Bishop

Categories: Smart home

As we wrote previously, the Sense energy monitor collects both your home's total electricity use and the electricity use of specific devices in your home. In the Sense app, you can see both total electricity over time (e.g. 350kWh was used last month) and instant real-time electricity (200W is being used right now).

The Sense energy monitor

Sense offers the world's most popular home energy monitor. Sense's product design (and marketing) looks like it could have been offered by Apple — very clean and spiffy. I enthusiastically installed the Sense energy monitor two months ago.

Based on my experience so far, I unfortunately can't recommend it. This article will explain why, and will then propose what I think is a better option for confidently tracking your home's electricity use.

Why get an energy monitor?

By better understanding how energy is used in your home, you'll be in a better position to take control and cut your energy bill. An energy monitor can help you identify easy ways to save energy. For example, I noticed in the Sense app today that our lower bathroom's overhead light uses 60 watts of power — I thought there was a low-energy compact fluorescent bulb in that fixture, but the Sense app revealed that it actually has an old-school incandescent bulb. Let's swap it out with a spare compact fluorescent bulb.

For other energy-monitor benefits, see the above-referenced article.

How does the Sense energy monitor work?

The folks who brought us the Sense energy monitor were previously major contributors to voice-to-text technology. They brought their expertise in analyzing voice soundwaves to the smart-home electricity space. Every device in your home has a unique electrical signal — think of it like a thumbprint or scribbled signature. Sense attempts to identify the signal of each separate electrical device when analyzing your home's overall electrical signal (Sense only has access to the latter, via your breaker box). Their detection gets better and better over time, as they collect more data from your home and other homes.

How long does it take for Sense to recognize my devices?

I suspect many Sense energy monitor buyers assume that their home's devices will be identified within the first week or so. Alas, the device identification process takes several months (or even years).

Two months after my Sense monitor installation, many of the regularly-used devices in my home haven't been identified yet (examples: my clothes washing machine, and all but one light bulb).

What happens when Sense identifies one of my devices?

Sense will send you an email, and the device will be added to your list of identified devices in the app. Sense will either give the device a specific label (if they think they know what it is) or just give it the generic "Device" label. Either way, you can re-label the device in the app (which is fortunate, because my Sense-provided labels were mostly wrong). You can also indicate which room the device is in (but you unfortunately can't organize devices by room).

It could be a bit of a scavenger hunt to find out which device in your home was actually identified. Especially if it's something hidden away like the fridge defroster. Or, worse, if Sense doesn't consistently recognize that device (see the next section).

My device list in the Sense app

Does Sense remember identified devices?

I assumed that once Sense identified a device, it'd know that device forever. So it'd just be a matter of time before Sense had my home's devices mapped out with 100% confidence (this was a big consolation after realizing that Sense's device identification would take several months).

Unfortunately, this hasn't been the case. It was mildly thrilling to turn on the toaster oven and, a few seconds later, see "toaster oven" move to the top of the list in the Sense app as a currently-on device. Unfortunately, turning the toaster oven on a week later only increased energy use of the app's catch-all "Other" list item.

And I previously decided an identified device was the fridge defroster because, for the life of me, I couldn't identify it elsewhere. I proudly labeled it "Fridge Defroster." Several weeks later, "Fridge Defroster" came on in the Sense app when I turned on the toaster.

Sense's unreliable device remembering is a deal breaker for me. This means I can't trust the app's real-time reporting or its historical energy data. Perhaps there will come a day when Sense has collected enough data about my devices to be 100% reliable (it's recognizing my toaster oven again)... I'll give it another shake in a few months.

Can I train Sense?

I read that Sense had a training feature early on but they've since removed it. The idea is that you'd make your home as "quiet" as possible (in other words, turn off everything you can so very little electricity is being used). You'd then indicate in the Sense app when you turn on and off a specific device, repeated several times.

I'd think this relatively clean data would put Sense in a much better position to identify that device. I don't know why they removed that feature. A competing energy monitor offers a training feature — I look forward to sharing a related review.

Sense's phone app and web-browser app aren't consistent

For some reason, Sense's web-browser app currently indicates that our bedroom dehumidifier is turned on even though that device is unplugged. The dehumidifier is correctly listed as off in the phone app.

I separately noticed that when turning a device off, it might take the web app a minute or longer to reflect that (the phone app is much more responsive).

Smart plugs to the rescue?

A workaround for Sense's sub-optimal device detection is to integrate with Kasa or Wemo smart plugs. Sense will have a direct connection to those Wi-Fi connected smart plugs, so will immediately recognize the devices plugged into them. I tried this with both Kasa and Wemo, and it seemed to work as expected. As a bonus, you can turn those devices on and off directly in the Sense app.

Unfortunately, the Sense app doesn't reliably indicate whether those devices are on or off. Let alone that I can't reliably turn those devices on or off from the Sense app.

This could be because my internet isn't fast enough, although I'm using the fastest internet plan available in the Bay Area, California. ...With Eero for further home internet enhancement.

I was hoping that Sense would use the direct data connection with the smart plug to permanently identify the device plugged into that plug. This way I could rotate a few smart plugs around the house to eventually get all devices mapped in Sense. Unfortunately, Sense will only recognize the device so long as it's plugged into the smart plug.

Will Sense's energy-use totals match my local utility's?

Some Sense users indicated in Sense's online forum that they're just relying on Sense for data on whole-home energy use. Some utilities don't provide hour-by-hour energy use data to their customers, while Sense does.

I compared Sense's energy-use totals with my utility's. Sense reported 367kWh used in April and 273kWh used in May, while my utility reported 362kWh in April and 269kWh in May. Pretty close.

Understood that Sense can't be expected to exactly match the utility's energy-use totals — the utility will include estimates when their data-collection technology occasionally fails. And Sense won't collect data when it occasionally loses Wi-Fi access. But this unavoidable discrepancy means we can't rely on Sense energy data to exactly recreate the utility bill.

Conclusion on Sense

I appreciate that Sense is pioneering extremely complex technology. Three cheers for Sense!

But the Sense energy monitor isn't reliable enough for me. I see its potential to be much more powerful and reliable down the road (thanks in part to contributions from underwhelmed early adopters).

A better option for mapping out your home's energy use?

Kasa offers a smart in-wall outlet. It'd be expensive to replace all in-wall outlets throughout your home (the Kasa outlets starts at $34 each). But with this approach, there's no chance that a device won't be recognized or will get mixed up with another device (assuming each device gets a dedicated outlet spot).

The Kasa app also shows real-time and historical energy data for each device. And, unlike the Sense app, turning on or off a device in the Kasa app immediately turns the actual device on or off. Kasa also offers smart lightbulbs. I look forward to trying out this alternative approach and sharing a related review.

(Note: we have no connection to Kasa and haven't received anything from them.)

Author: Michael Bishop

Michael's core purpose is to improve the customer experience around going solar. He primarily pursues this by writing articles and software at CutMyBill.