Energy use monitoring - Open Energy Monitor?

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QueenBee

Well-known member
Joined
Aug 8, 2010
Messages
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Location
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I've been thinking about and researching solutions for energy monitoring for a long time but have yet to pull the trigger on anything. I'm curious what other have implemented and your thoughts.

I'd like something somewhat accurate but more importantly reliable with long term support. I want to be able to monitor my four large 240 volt loads, then solar PV generation and power consumed/delivered from/to the utility. I don't know what percent of my consumption that would be but then monitoring additional 120 volt circuits so that it ends up being the majority of my consumption.

Bonus support for monitoring individual receptacles.

Phase 2 would be cold and hot water usage and then natural gas.

I've seen some commercial products that are based around this level of detail for example the Powerhouse Dynamics eMonitor: http://www.powerhousedynamics.com/residential-energy-efficiency/" onclick="window.open(this.href);return false; but $15 a month is hard to swallow.

Open Energy Monitor seems like a good solution as well since it can be configured in any fashion I can dream off. The main concern I have is the amount of work needed to build and configure everything. Then I worry how reliable it will be.

I keep hoping Enphase or Nest come out with a solution for this.
 
QueenBee said:
I've been thinking about and researching solutions for energy monitoring for a long time but have yet to pull the trigger on anything. I'm curious what other have implemented and your thoughts.

I'd like something somewhat accurate but more importantly reliable with long term support. I want to be able to monitor my four large 240 volt loads, then solar PV generation and power consumed/delivered from/to the utility. I don't know what percent of my consumption that would be but then monitoring additional 120 volt circuits so that it ends up being the majority of my consumption.

Bonus support for monitoring individual receptacles.

Phase 2 would be cold and hot water usage and then natural gas.

I've seen some commercial products that are based around this level of detail for example the Powerhouse Dynamics eMonitor: http://www.powerhousedynamics.com/residential-energy-efficiency/" onclick="window.open(this.href);return false; but $15 a month is hard to swallow.

Open Energy Monitor seems like a good solution as well since it can be configured in any fashion I can dream off. The main concern I have is the amount of work needed to build and configure everything. Then I worry how reliable it will be.

I keep hoping Enphase or Nest come out with a solution for this.

If you loosely adopt the open energy monitor pickup circuit for voltage and current on the main legs, or however many circuits you want to monitor, an arduino with a wired ethernet connection provided a stable solution for me. It has been running over a year, without problems. The monitoring can be done from a linux machine, which then archives and serves the data. Most of the work was actually writing the software to do all this, but in the end, you have a system that does exactly what you want.
 
Did some more googling and came across this: http://www.garagejournal.com/forum/showthread.php?t=162749" onclick="window.open(this.href);return false;

Looks like the GreenEye Monitor is what I'm looking for.
 
Many of us also use the TED. Steer clear of it though if you use a large Insteon system or the like and can't put the TED MTU on a dedicated filtered circuit as such systems play hell with PLC... There is currently a $50 rebate on it.

http://www.theenergydetective.com" onclick="window.open(this.href);return false;
 
I use http://www.welserver.com" onclick="window.open(this.href);return false;. Its neat and a fun do-it-yourself system.
 
I've had a TED system for a while. I wanted something that had a few more features, like monitoring graphs that are more pleasing than the very aged TED options. I also wanted something that was more open. I know TED has some APIs that I could use but I liked the look of Open Energy Monitor as I was also building a Open EVSE too.

Anyway, I ordered the EmonPi and a EmonTx from the UK. I got mine and i've had to set it up a little different to the UK way.. since we are on two hots with 120V each in the US over the 240V single fashion in the UK, which the Op Ene Mon comes from. So I've had to use two CTs for the house usage and i've got 1 CT on the incoming solar and doubled it, not perfect until I get another CT to cover the two lines I have coming in from my array of 12 mirco-inverters.

I especially like the Solar usage app that is built in.

emonpi_solar_user_graphs.png


you can see the peaks.. during the day my wife plugs in her 6.6kW charging leaf and at night you can see my 3.3kW charging leaf. and I can see the fridge and freeze powering up patterns in there too. along with cooking and other activity.

i tried my hand at putting together some of my own. One thing I wanted to see was the balance between hot line 1 and 2 to see if one leg was getting more usage than the other. Over two days they are within 1.5 kWh. so i have more work do to but the wife has been using the microwave much more than usual over those days and I don't recall if the blender was on the same side as that. though they are short term usage. i did try to guess at balancing the loads between the two lines when I upgraded the panel. maybe a revisit is required?

line_1_and_2_power.png
 
Take a look at the eGauge. It's not super fancy or sexy, but it has it's own built in webserver, they're located in Colorado and have been around a while, and their support is top notch. It's a solid device. The built-in webserver means there are no ongoing hosting fees.

Personally I have a brultech meter and a bunch of semi-home brew stuff pushing the data all over the place. If you want a set-it-up-and-forget-it, try out eGauge.

interface.ed878cc52823.gif
 
DuncanCunningham said:
I've had a TED system for a while. I wanted something that had a few more features, like monitoring graphs that are more pleasing than the very aged TED options. I also wanted something that was more open. I know TED has some APIs that I could use but I liked the look of Open Energy Monitor as I was also building a Open EVSE too.

Anyway, I ordered the EmonPi and a EmonTx from the UK. I got mine and i've had to set it up a little different to the UK way.. since we are on two hots with 120V each in the US over the 240V single fashion in the UK, which the Op Ene Mon comes from. So I've had to use two CTs for the house usage and i've got 1 CT on the incoming solar and doubled it, not perfect until I get another CT to cover the two lines I have coming in from my array of 12 mirco-inverters.

I especially like the Solar usage app that is built in.



you can see the peaks.. during the day my wife plugs in her 6.6kW charging leaf and at night you can see my 3.3kW charging leaf. and I can see the fridge and freeze powering up patterns in there too. along with cooking and other activity.

i tried my hand at putting together some of my own. One thing I wanted to see was the balance between hot line 1 and 2 to see if one leg was getting more usage than the other. Over two days they are within 1.5 kWh. so i have more work do to but the wife has been using the microwave much more than usual over those days and I don't recall if the blender was on the same side as that. though they are short term usage. i did try to guess at balancing the loads between the two lines when I upgraded the panel. maybe a revisit is required?

line_1_and_2_power.png


I just ordered mine! I'll be PM'ing you when I get it since i'll need to do the US setup too.
What CT's did you use?
 
i used the CTs that came with the kit. They are reasonable priced. though I needed two for just reading incoming power and I'd like another two ( i only have one right now) to read my solar array.

I can go through the setup screens on how mine differed to the videos. I was quite easy once i figured out the process and what I was doing.

not sure If I should create my own video or just screenshots of the process I went through.
 
oh forgot to mention. I have a EmonTX as well as the EmonPi because it only has ports for two CTs. since I would like, at least, 4 I bought the EmonTx too, which has another 4 ports for CTs.
 
Cool, I went with the EmonTX and it's 4 inputs along with the wifi kit to make it standalone.
I didnt get any of their CT's because I know it wouldnt fit over my 100a mains (theirs has a 13mm aperture and I need at least 16mm) so I'll have to source some other ones. I'll be running 4 total since I have the 2 mains to watch as well as 2 solar feeds (though I could probably do just one and double it... but in for a penny...)

Where this will get really fun is using live-monitoring to figure out what my base daytime load is to see if its cheaper to charge the leaf (or run dishwasher etc) during day when solar is producing or at night during off-peak!
 
i didn't have any trouble getting the CTs over my 100AMP lines, they are aluminum but I don't know the size, I just know they cover them easily. They most definately do not fit over the 200 AMP coming into the service panel. I'll take some pictures and post up tomorrow.

You don't need a wifi on the EmonTX as it will talk to EmonPi via RF.. but that is ok.. wifi is probably more reliable and less prone to interference. I just haven't used wifi on the EmonTX.

I currently read just one of the hot lines coming in from my array and double it but the readings from the microinverters and the CT do not match up as closely as I'd like. again this system is open so if I see that all I need it to increase the reading by, say, 3% I can put that in to the calculations from the INPUTS to the FEEDS.

Best guide was here https://guide.openenergymonitor.org/setup/

and setting up the inputs and feeds helped a lot here https://guide.openenergymonitor.org/applications/solar-pv/#sensor-installation for the solar part.

this needed a reading too https://guide.openenergymonitor.org/setup/north-america/

the guy mumbles a lot so it can be hard to hear him but I'm more tuned into it than most since I'm British anyway. Things to remember.
1. EmonPi is powered by the USB 5v unput, not the AC adapter, that is just for reading the power.
2. Switching off the emonPi is done by pressing in the little peg indented that you can reach with a pencil and only unplug the power once it says so.
3. it can take up to 2 mins to fully boot up.
4. I created an account on my emonpi and created the very same username and password on the emoncms.org for simplicity, they don't have to be the same but I did that.
5. if you screw up it's ok, you can start over again as the inputs are automatically recreated for you so you can get going again.
6. watch all the videos and read the guide as you go.. read over it a few more times if you don't get it and read over and over it if you don't seem to be getting the results you expect.

There was a couple of things not matching from the guide and video but I got through it and now I'm little more comfortable than I was the very first time I switched it on and was wondering what it was all about. I'm no geek.

I might just get my system and reset everything back to stock empty and go over everything i did and record it. I don't know. I might have enough spare time.
 
Thanks! I finally got all the gear and went on to install... and not being a programming/network geek either its certainly not intuitive! It looks like i've somehow locked myself out and now I need to figure out how to do a factory reset!

oh boy... it looks to be worth it once I get it up and running but we'll see! I hope to integrate my openevse feeds to it too

thanks again,
jeff
 
Beardedjeff said:
Thanks! I finally got all the gear and went on to install... and not being a programming/network geek either its certainly not intuitive! It looks like i've somehow locked myself out and now I need to figure out how to do a factory reset!

oh boy... it looks to be worth it once I get it up and running but we'll see! I hope to integrate my openevse feeds to it too

thanks again,
jeff

Start with the local box only. That way you become familiar with that before connecting it to the CMS web part.
 
So after a few back-and-forths with what i'm assuming was some bum hardware or programming on my part I finally got it all up and running!
I will say, the OpenEnergyMonitor is pretty slick to use once you get it figured out.
I really like the real-time view of our system and home usage.
https://emoncms.org/app/view?name=My Solar&readkey=ee14d418fe3c1f96873aad09a068ed4c
I have 4 current measurements going so its a pretty accurate setup:
House Line 1 and Line 2
Solar Line 1 and Line 2

The biggest spikes in usage are the coffee maker and the Leaf!

Thumbs up to Open Energy Monitor
 
I went ahead and bought some CTs that would fit over the 200amps lines so I could see everything. I've not really touched it since. I look at my net usage all the time and my evse is integrated into the feeds too so I can see what I'm pulling for cars, house and solar. To change something, you need to be informed about how you are using it.
 
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