Do you have any experience with Home Energy Management Systems?

In My Humble Opinion
1

[ETA: Sorry this turned out so long.]

Background: Last spring we had our old asphalt driveway torn up and expanded with stone pavers, and had an electric snow melt system (SMS) installed under it, because the driveway is rather steeply slanted, and ice and snow can make it hard to get out. (We’re not allowed to park on our narrow street in the winter.) The old one-car asphalt driveway had had a similar system, installed decades ago, but it hadn’t worked for a very long time.

The new SMS’s heating mats do not cover the whole 25x30-foot driveway, but are only under the tire tracks where we park the cars (as indicated by the color of the pavers). But even with that relatively small area, they draw A LOT of power. They’re rated for slightly over 40 amps.

When the SMS came on automatically for the first time a few days ago, it drew about 10 kW while it was on for about nine hours, putting our consumption for the day at over 100 kWh, compared to an average of about 15 kWh on the days around it.

I know this because we have solar panels and the Enphase Enlighten app that monitors our electric production and consumption for the house. So when I suspected that the SMS might have activated, I checked Enlighten, and sure enough, it had come on at about 3 a.m.

The SMS has two ways to indicate that it’s on: 1) a bright green light on the outdoor sensor next to the garage door starts flashing when the temperature drops below a certain point and it detects moisture on its upper surface. (Both these settings can be adjusted.) And 2) a smaller yellow LED on the control panel inside the garage that starts flashing when the system activates. The outdoor one is not visible from inside the house, and therefore not very helpful, and the garage one is only slightly more so. It’s on the other side of the wall from the sensor unit, so I can open the door between the house and the garage and see it on the far side of the garage.

But unless I go into the garage, there’s no way to know that the SMS has gone on. Ideally, I’d like to get a text or some other push notice whenever it switches on so that a) I can manually turn it off if (as was the case the other day) there isn’t going to be enough accumulation to warrant its use, and b) I can adjust the various settings to be more effective and efficient.

The SMS itself has no built-in capability to alert me, nor does the Enphase system. (I’ve suggested this upgrade to both companies.)

So finally to get to the point of my OP. I’ve been looking at home energy management systems (HEMS) that seem like they could do this for me, and wanted to get the benefit of the Dope’s experience with these systems.

Wirecutter has reported on them, and finds that most people can save almost as much power without them as with them by taking a few simple, basic steps. Be that as it may, I think a HEMS might be a workable solution for my purposes, and the question then becomes, which one?

Wirecutter recomends Sense, Generac, and Emporia. The last is the most basic and least expensive, but it looks like it could handle my primary needs, and could be expanded if I want to monitor more circuits.

What do you say? Do you have a HEMS, or experience with them? Which one(s)? Do you recommend it? What are the pros and cons, etc., etc.?

Or can you think of another way to do what I want to do?

Thanks!

2

I don’t have any experience with the three systems you mention (I wouldn’t be starting from where you are), but note that your system already has the load consumption reporting: all you are looking for is the alerts. That’s a software solution.

I think you can get the alerts using home-assistant.io ,( Enphase Envoy - Home Assistant (home-assistant.io) or, if you’re into this kind of thing, using the published Enphase API and IFTTT (If This, Then That). IFTTT is more flexible, and under your control, but requires reading and understanding the Enphase and IFTTT API documentation. The Enlighten Systems API (enphase.com)

There may be an alternative to home-assistant.io. I’m slightly surprised that I didn’t see a listing of compatible software at Enphase: they’ve published the API, so they must have considered the possibility that the big building-automation companies would provide support.

3

Thanks for that suggestion, but it seems as though using home assistant requires dedicated hardware. I have a Raspberry Pi set up as an MP3 media server, and I have a working Windows PC that is not doing much.

But from my admittedly quick reading, it looks the Raspberry Pi install requires a whole new operating system on the device, which would probably mean I couldn’t continue using it as it is now, so I’d have to buy another Raspberry. Am I wrong about that?

The Windows install requires a Virtual Machine with Linux, which looks a little more complicated than I’m willing to take on.

As for working directly with the Enphase API, that’s waaaayyyy beyond my technical capabilities. Thanks anyway.

Anyone else have any experience with HEMS?

4

I’d make a simple hardware monitor circuit.
Just have a photocell watch one of the indicator LEDs, and have it push an alert to you.
An ESP32 module could do this easily.

5

Y’all are way more tech-savvy than I am. If I were 20 or even 10 years younger, I might have dived into the solutions you and @Melbourne have suggested, but I just don’t have the patience, curiosity, or inclination to try to master new tech any more.

And if I did, I’d probably forget how it all worked by the time something went wrong in a few months, and have to try to relearn it from scratch. That’s what happened with the Raspberry Pi, which I originally set up for Pi-Hole, but which didn’t work right affer we moved and had a different router. It’s been more than 2.5 years, and I haven’t had the gumption to try to figure out how to get it working again. Plus, I’ve had a lot of other things that were more important.

But it’s on my “to do” list.

6

Would something like this work?
https://www.amazon.com/Current-Amperage-Voltmeter-Multimeter-Transformer/dp/B07JB9B2QL/ref=sr_1_2_sspa?crid=DMWQIC64MIWR&keywords=current%2Bmonitor%2Bremote%2Balarm&qid=1702309659&sprefix=current%2Bmonitor%2Bremote%2Balarm%2Caps%2C148&sr=8-2-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1
You can run the sensor wires as long as necessary.

7

Actually that’s not true. Home assistant can be run in a docker container on the PI, or and other OS running docker.

Installing Home assistant in docker

That’s the way I do it. I don’t particularly like the Hassos managed environment.

8

Thanks, @Tatterdemalion, for that update. But it’s still way too complicated for me right now.

I’ve just got off the phone with tech support at Emporia, and they say their most basic system ($85) will send an alert to my phone, which is all I need. I can start with that and then decide if I want to add up to 16 sensors for other individual circuits and our solar panels.

So the only other question is whether to get an electrician to install it for me (and how much that would cost), or do it myself. In principle, installation is pretty easy, but my wife would probably have a heart attack if I told her I was even thinking about it.

Although the suggestions for alternatives were interesting, thanks, I won’t be following up on them. But I’m still interested in anyone’s experience with HEMS like Emporia or the others.