Best energy monitor?

Been looking at energy monitors, and trying to figure out which one is best. A lot of people say sense sucks at detection. For background I don't have solar, but will be installing a generator soon. I've seen Generac even makes them now.

So what's good?

To me, the v1 Aeon are good. They’re old 300 series Z-Wave, but I have three of them on a separate hub and they are accurate. You can still find them on eBay for around $50

I had Sense for a while before returning it. It's expensive, but very accurate. It's detection is eventually very good for most devices, but it's difficult to integrate it with anything. IFTTT was the only option for HE in the past. With the way things are going for IFTTT, I don't think investing that much in a cloud solution that might not be there in a few months is worth it. Reaction time was around 20 seconds too.

Since I had Sense and an Aeon v1 at the same time, I could compare accuracy. There's no question that Sense can get a much more accurate graph of your appliances and usage, but as far as levels the Aeon was only off by a few watts. I do recommend keeping them on a separate hub, but the cost of another hub (especially with the sale price right now), together with a Aeon v1 HEM is still much less than Sense. Nice to have a second hub to add devices that might otherwise mess with the speed of automations and meshes on the main hub too.

I use this driver for Whole Home monitoring

And I use HubiGraphs for viewing in Dashboard

My other two HEMs I use for appliance monitoring. I've modified this driver code so that it checks every second. This works great for notifications of appliance state.

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Emphasis on the word eventually. I've had Sense for over 4 years. It is really good at identifying large resistive loads, but terrible that many inductive loads - especially things like a dual-stage compressor (or a variable speed compressor).

There is an unofficial Node-RED integration that works quite well.

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I love my IoTaWatt Energy Meter device.

I also wrote a simple IoTaWatt integration for Hubitat.

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Are you using the single CT on the mains? Or the individual ones? Should I order ones for every circuit or just for mains? And do I need 2 for the mains?

There is this product/system that some of my (prospective) clients use...

I do not have any experience with the product but it looks interesting.

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I was an early adopter and have had Sense for 4.5 years. It is really good at tracking overall energy consumption, but machine learning to pick up individual devices leaves a lot to be desired. It isn't bad for resistive loads, especially high-wattage resistive loads, but is not at all good with inductive loads, especially inductive loads that can vary based on operating conditions (eg. multiple-speed motors or variable speed motors).

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To whom are you replying/asking? If me/IoTaWatt, then I use two 200A CTs for my mains, and another dozen smaller CTs to monitor branch circuits. In some cases, I double up and measure 2 branch circuits using a single properly sized CT.


This is actually a more desirable setup than Sense and its machine-learning based device detection.

One question. How does iotawatt do power factor correction?

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That has been my experience. Maybe as a whole house monitor it's useful...but for individual items. I've had this thing for at least 2-3 years and it's still wrong.

It uses a 9VAC transformer to monitor the actual voltage and phase of the incoming power. This is then used to measure actual power usage as well as power factor.

The entire IoTaWatt project is open source, so one can review all of the source code if desired, as well as the hardware schematics. The developer lives in New Hampshire and is always improving both the hardware and software. He is very responsive to user questions in his community forum.


Sadly, the likelihood of my understanding either is zero - so I rely on the experience of those who do!

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I've been using BlueLine's Energy Cloud. I'm not sure it's the best solution out there, but it fills my needs. It sends automatic notifications based on monthly comparisons which helps keep electricity usage in check. It also has an informative graphical UI that shows historical, current and projected usage,

I've been interested for most of this year in this kind of power monitoring but found the devices costly and lacking. But you, @ogiewon, just sold me on this one with those words.

I looked up the thing a few hours ago and put a combo in the cart but was still on the fence. No more.



We have a real old The Energy Detective (TED1001, I think). It sits on the kitchen counter and I look at it whenever I'm there. It can handle a second set of CTs, so I put them on the (non-standby) generator input lines (before the lockout). No fancy graphs or anything. I look at upgrading every couple of years of so, but never have. We're looking at a standby generator now-they all have wifi now.

I like the Generac, I have had mine for about 4 years now. But their Wifi device is inferior in every way to the Genmon project that you can run on a Pi. I would rip out the built-in Wifi and not let it ever talk to the cloud at all if I got a new generator.

Not to derail too much, but we got a quote on a Cummins. The Generac guy is coming in a couple weeks.

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I like my Eyedro monitor. It is a dumb monitor, and it doesn't integrate with anything. But it does keep good track of consumption, has some nice graphs, and keeps a long history. It includes a bunch of good analysis tools. It was fairly inexpensive compared to others out when I bought this maybe about 3 or so years ago.

They are currently about $100 for the wired (ethernet) version, which is what I have.

It just struck me that using wifi to keep an eye on generator activity would likely not work in my neck of the woods, 'cause when power is down, cable is down.

Way derailed at this point, but I have an 11KW Generac on propane that I installed myself, including the transfer switch. It is not a whole house setup, the transfer switch is after the main breaker. So I can run most of my house but not everything. It was less expensive and easier as I didn't have to have the main service disconnected to do this, and the transfer switch was a bit cheaper. Oh, and I could use a smaller less expensive and more fuel efficient generator.

I really just needed heat, water well, and basic lights. I live out in the country and rely on a well for water and I don't have a wood burning fireplace or any backup heat source so I needed something. In reality I the only things I can't use are the washer, dryer, and a handful of less important circuits.

Funny thing is that previous to getting the generator, the power would go out fairly regularly. I have only run it about 4 hours in as many years since. :smile: But at least I have it if needed.

Should have included this: