Love this product!

Just wanted to give a big thumbs up on my first full month of monitoring / stats using Iotawatt.

I’m off-grid w/grid-assist and have dual 12,000w inverters. For me, it’s not the individual home circuits that I need to monitor as (after 5 years of off-grid solar) I have a good handle on what each circuit might use, but it’s the load on each inverter and the power distribution by leg of each inverter that’s of particular interest for me. I’ve long wanted a way to track / record what’s happening in detail.

Iotawatt is straight-forward and I can pull data directly to my DIY monitoring software. With the 02_08_02 Firmware version it’s operating flawlessly, even when the inverters are off (e.g 0v VRef).

As I’ve come to understand more about Iotawatt it’s just fantastic for my purposes. The Graphing is more than adequate and simple/easy - like this graph of inverter load over the last 24hrs…

You can see 0w when Inverters turned off for the night due to low battery.

I use the ‘direct’ API query feature of Iotawatt to my local DB and I can now find spikes to see how close I’m coming to max Inverter capabilities per leg etc. For example, in Feb I had a peak of 5,795 watts on 1 leg of the 12,000w inverter for a bit - showing me that I’m right at the max the Inverter can do.

The first month’s totals seem perfectly accurate for my purposes. Not suggesting Iotawatt might not be accurate - just adds confirmation for me. I’ve been using cheap meters on the Inverter output legs…

and adding them up for total consumed power. For Feb, 2023 the meters showed 895kwh of output from the Inverters and Iotawatt showed 920kwh - pretty close. In fact I’m hoping Iotawatt is more accurate which gives me an 85.7% efficiency metric compared to the incoming PV kwhs whereas the meters give 83.3% efficiency.

The API query → my local DB let’s me enhance my dashboard with this kind of info

This time of year (low PV in winter) I only run 1 x inverter to keep load hi for better efficiency and this info is highlighting how close I’m coming to max. Will be time to reconfigure the load distribution panels for both inverters soon.

In any case, just wanted to do big shout-out to how useful this system is.


Finished my IotaWatt setup - using 3 separate Voltage Refs - very nice / easy to setup.

I can now see each 120v leg output of both inverters. Plus, I can see the incoming generator (battery charging power) 120v legs.

This will help me manage when to have one or both inverters active. In addition, I can extract equipment run times for the 3 sources of power. The Red / Black are the wire color of L1 and L2 at the distribution panels so I can trace the metrics to circuit distribution at the panels.

Bonus: I can see the Hz of each power source. Icing on the cake for me as one time I accidentally left an inverter at 50Hz instead of 60Hz and it wasn’t immediately obvious.

Tip: Finally realized that “Outputs” are shown in alpha-numeric order from top to bottom and was able to arrange them for my liking by judiciously picking label names :slight_smile: