Iotawatt for individual circuits only

I have decided with my system that is already monitored by the Tesla Gateway (solar plus powerwall) that I would like to use the Iotawatt to monitor some individual circuits (ie GSHP, EVSE, hot water heater). This is a basic question but wanted to make sure I can use the Iotawatt without total consumption monitoring. Can I use the pvoutput uploader to only upload extended parameters (I’m a paid contributor) as well without configuring consumption or generation?

You can absolutely measure whatever you want with IoTaWatt. There is no requirement to measure mains.

Unfortunately, PVoutput requires that Consumption or Generation be included in any status upload of the extended parameters.

If you are talking about HASS Energy, then you specify what entities contribute to those calculations. If you don’t include any IoTaWatt sensors, then it should not impact anything.

I don’t know what you are using right now to upload energy information to HASS Energy, but last time I looked most of the uploaders send power information which is integrated by HASS to get Energy. Any missed data points, whether from network or HASS downtime, could result in lost Energy. Also, the longer the sample interval, the more import and export become muddled. FYI IoTaWatt does all of those calculations locally and uploads the running total of import and export, so that even when there is a communication or HASS lapse, the total energy remains correct.

That’s fine. Accuracy is a relative term. IoTaWatt is typically within 1% of your electric meter. For a powerwall, IoTaWatt would measure the AC that flows to the battery and the AC that flows out. That factors in the efficiency of the charger and the inverter to measure the real performance of the system. I don’t have a powerwall so don’t know how they develop their numbers. When you do it all with IoTaWatt,

Grid Import + Battery output + solar output = Grid export + Battery input

Similarly, Battery efficiency is

Battery output / Battery input

That measure needs to be taken over a long period so that battery charge state is not a significant factor.

I’m not advocating that you change anything. Just informing your decision. If you current monitoring matches your meter to your satisfaction, you probably don’t want to mess with it.

IoTaWatt/Powerwall users feel free to chime in here with your experience.

If you can get that working, let me know. The Home Assistant IotaWatt integration fails to work for me.

So exporting when not charging = 100%, importing while not discharging = minimum reserve SOC.

That is something I can consider when I get going with the ESP32 again. Probably just needs to add a bunch of new capability to the calculator scripts and then an integrator could maintain the SOC.

I’ll think about it and maybe get a bright idea of how to squeeze it into the current ESP8266.

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The major issues with those assumptions, of course, are if the batteries are turned OFF (exporting to grid would occur automatically) as well as battery discharging below minimum reserve when grid is down. The latter is easier to deal with logic than the former, but the former would be a rare event. Nevertheless, the assumption logic should automatically “reset” to approximate accurate levels once the system resumes normal operation with both battery and grid functioning. Thanks for your consideration!