22 days using the Sense Home Energy Monitor

June 19, 2017 Paul E King 6 Comments

The Sense Home Energy Monitor is an electrical panel power listening device that can help you track down what’s causing your electric bill to be so high.

It can also tell you at the movies that no, you did not leave the stove on when you left the house.

I first heard of Sense at CES earlier this year. It sounded neat and I ended up hounding them for a couple of months to do a review.

Head to head: The energy monitors we’ve tested

We covered a system that did some of the same functions a while back while I was searching for my mystery power drain.

They’re different systems and I’ll cover more about that later but the short of it is if you want billing estimates, web interface, and predictive reporting for corporations or penny pinching you go with Eyedro.

If you want to figure out what’s draining your electricity, be able to see what is currently on in your house, and will help you get control of your unexpected power drain you go with the Sense Home Energy Monitor.

The install

The instructions on the Sense say you want an electrician. For me this is probably a necessity as the incoming lines are too freaking close and had to be unseated and reseated. You’ll also need to connect power to a 240 breaker.

I’ll stress these are pretty easy things to do, but both carry the ability to kill you. I might do them on a unit where I could easily turn off the power and pull a breaker. I do not trust my particular wall panel even though two electricians have said there’s nothing wrong with it.

Connect one AC 120volt power supply to one extremely well greased up 12 volt DC engine and you’ll understand why at a very early age I learned to respect electricity.

My electrician dropped by, swapped the Eyedro for the Sense as there was no way both were going to fit into that little box, and that makes me a bit sad as I really did want to do a head to head comparison.

About a minute and a half after powering up we hadn’t heard anything from the Sense unit and were about to investigate when it beeped.

Electrician had done his job and he left. Total time about 10 minutes.

The Sense Home Energy Monitor setup

Pretty short one. I positioned the WiFi antenna a little further away from the electrical box as that seemed like a bad WiFi area, connected to my home 2.4ghz WiFi. Had to do this twice as the app claimed it failed and then it worked. So not sure on that one.

It was up and running and showing me one large unknown bubble. It said within a few days I should expect to see devices identified. At this point I could see how many Watts were being used, but not too much else.

My first or second weirdness

I installed this on Monday, May 29th 2017 and I got a message on June 1st that Sense support had corrected an installation problem and everything now looked ok. I asked support what had been done wrong and got back that something looked as though it had been having problems at a time before the install.

OK, that was odd, it started working at day two. I’m not going to sweat a false alarm although if I’d been anxiously awaiting things working that day delay might have annoyed me.

And then we wait

The crowning achievement of Sense is that it can make a smart home out of a dumb home. Unfortunately this takes time. The signatures of all your electrical devices have to be listened to and sorted in their normal use scenarios.

You can’t train the Sense Home Energy Monitor.

And then it starts working

June 4th was the first breakthrough moment for me. This was about a week into the install I started getting different devices identified. It found my main fridge and the water heater.

It also found an unidentified motor, had classified a group of always-on but unidentified devices, and some other things it hadn’t worked out yet what they were.

I renamed a couple of things as I was able to spot what they were doing. I’d set up the app to alert me when any of these devices turned on or off so that I could rename it.

By week two the fridge, mini fridge, a light fixture, curling iron, water heater, and a couple of other things were identified correctly and were showing up on the timeline.

I could turn the lights on in the bathroom, my phone would chime the lights were on in the bathroom. I’ll point out I had it set to tell me because I am reviewing this thing, you don’t have to be alerted if you don’t want to.

The main AC, deep freezer, washer and dryer, a room air conditioner, and most electronic gadgets were not detected yet.

And then it stops working as well

It went from a high of 60something to mid 90s one day. It got so hot upstairs my little portable AC unit (only turned on to supplement the main AC) couldn’t cut it. I had to break out the Spare Conditioner which I keep on hand for times like this and to loan to anyone who’s central AC is downed for a day or two.

I plugged that in, kicked it on, ahhh sweet coolness.

Unfortunately this cheap-o AC unit has the effect of screwing with the Sense. That or there’s an amazing timing coincidence.

The small things stopped showing. The bathroom lights could no longer be “heard” over the air blender’s mayhem. The icemaker in my refrigerator which runs 6 minutes suddenly was reporting 30+ minute runtimes. The microwave said it was on when it was not.

Things were terrible… for about a day.

Then Sense appeared to learn. It started with the big ticket items. They started being detected correctly again. The very low Wattage things such as the bathroom lights don’t seem to have detected yet while the AC is on but everything else appears to.

Sense keeps learning

It had gone for a few days without learning anything new and then it finally got the big one. The central AC was recognized. The deep freezer after that. It picked up a few small devices and my hope is that when I turn my computer on and off a few times it’s going to manage to get that as it can see what’s broadcasting on the WIFi.

As of 22 days in it has not detected a running 500 watts of other stuff.

The Sense Home Energy Monitor may frustrate you

You will have to play Sherlock Ohms sometimes as this isn’t entirely automated (yet) – it gets better as more people get it and device signatures of thousands of homes get pooled, however as I’m fond of saying even if it has the possibility of getting better you buy the product that’s there now. That product isn’t without some frustration.

The most frustrating thing I have had happen so far is that while out I got a notification that the curling iron had kicked on and shortly thereafter the internet went down at my house. This lead to a Sense app telling me a curling iron was on and no internet made me think the house was burning down.

I was on the way home anyway, house had not burned down, the curling iron was not plugged in. I don’t know what it detected but evidently something in the house fooled it. That same something knocked out my internet. Brownout maybe? Pretty much not blaming Sense for this one.

What’s lacking?

Bear in mind I haven’t been on this a full month and things are subject to change as machine learning teaches the Sense database what is what out in the world and as the web and reporting side continues to be developed.

Google Assistant/Home integration would be nice. “Hey Google, what’s Sense reporting” would be nice.

A web interface with the ability to share stats, email daily/weekly/monthly summaries.

Alerts for when something is on and you’re not at home (eg curling iron, stove, etc) – ideally would get that the instant you disconnected from home WiFi.

I know it’s not how it works but I’d really like to be able to tell it “hey, I’m going to turn on the stove, would you listen and file this under stove sounds?”

An option to train when two devices sound similar. My coffee pot and my toaster sound the same to Sense. While this isn’t an issue for me, I think it would be pretty useful. You can currently report the issue and the Sense team can work on it, delete the device and let it redetect, or be like me and name it “coffee pot or toaster” until such time as more important things come up.

A little more calendar-like tracking. Their timeline is nice for a day or so but when I want to see KW by day by device it becomes a little meh.

What’s the advantage of the Sense Home Energy Monitor?

I’d managed to track my mass energy usage with the Eyedro to times. With the Sense I’ve managed to track it to devices. I’d guessed at my issue being the water heater and I was mostly right. Water heater in the $60 range. That’s not good and I guessed that with the Eyedro and confirmed with the Sense.

My always-on devices are currently costing me $52 a month. I’m still tracking these down but I finally have the ability to turn off breakers and see when they go off so I can figure out what’s costing me $600 a year in electricity that I don’t have a clue about.

As a note on the above, I could have done that with Eyedro, but I couldn’t be sure if the AC was kicking on or the fridge or another high-amp device.

So, the Sense Home Energy Monitor is hopefully going to help me save about $900 in the first year (getting new heating element/thermostat for the water heater, unplugging anything else when I find it). Realistically I’d say it pays for itself in the first year for me.

Your experience may vary.

What’s the cost/recurring cost?

Currently $299 for a Sense Home Energy Monitor. $50 more if you have solar. No recurring charges.

Any negatives?

Supposedly it initially eats up a decent amount of bandwidth as it offloads lots of electrical data to the Sense hq where machine learning analytics figure out what’s doing what.

Price factor right now feels a little high.

You probably want an electrician to install it unless you’re very comfortable with electricity. That cost me about $40. I think the average service call will probably be more.

Smart device in your network connected to the internet. While there’s not anything I can think of that could cause damage from the electrical panel, if hacked, it’s in your network. I mean, same can be said of anything in your network so that’s not a huge risk.

You will become Sherlock Ohms at some point wandering the house at 3am attempting to figure out what Motor 4 is.

I’ve learned along the way

In the Sense device loses wifi/internet connection, it will store up to six hours of data and send it when connection is reestablished.

Plugging in a large constantly running cheap product that the Sense has never seen before can affect reporting for a day.

Reading the forums people get extremely frustrated over it not being able to detect everything quickly. If you’ve got a low frustration threshold perhaps wait a few months until Sense has more data on houses with units similar to yours.