I am a little befuddled here. You have no idea how many scenarios I’ve dealt with, and yours was a long time ago. I don’t know how the powerwall is connected and I’m not sure it’s still the same with respect to how the solar ties in.
It might help to see an Iotawatt plot of a day with the raw solar, mains, and battery.
EDIT: I’ve looked at the powerwall documentation. I’m assuming you have a “partial-home backup system”. But I don’t think that’s important right now.
If I understand you correctly, you would like the PVoutput “consumption” to be the total of your loads sans what is going to the battery. I think that’s possible, but like the old Chinese saying, careful what you wish for, you might get it.
PVoutput is a very simple model. It takes in two metrics: The output of the solar inverter and the energy consumed by the home. From those numbers, it assumes any solar in excess of generation is exported, and conversely any consumption in excess of solar is imported. There are menu choices to display import and export.
Assuming “battery” is positive when charging and negative when discharging,I believe you can eliminate it from the consumption feed by subtracting it:
Consumption = (mains + solar - battery) max 0 [should not be negative]
Logically, this should also add in to consumption when the battery is discharging.
So PVoutput will not be able to know when you are exporting to the grid because it does not know if you are exporting to the battery or the grid. It also will not know when you are importing because it will not know if you are importing from the grid or the battery. If you don’t care about that, and it isn’t a part of the graph you seem to prefer, then maybe that’s OK.
I think there is another slight problem with this setup though. I don’t think it accounts for the efficiency of the powerwall. That is, if the powerwall is gives you back 90% of what you put in, I think you lose the 10%:
Lets say that while the powerwall is charging (or more accurately not discharging) your numbers are:
mains -5 kWh
solar 20 kWh
battery 10 kWh
So your consumption (sans battery) is 5 kWh
Now evening rolls in and your numbers are:
mains 20 kWh
solar 0 kWh
battery -9 kWh
So your consumption is 29 kWh
Total consumption is 34 kWh for the day. Yet you imported 15 kWh from the mains and generated 20 kWh with solar for a total of 35 kWh. Your battery is at the same state of charge as at the beginning of the cycle.
Just thinking out load here. Sure the battery time-shifts your consumption, and you can measure that with other outputs in IoTaWatt and/or Emoncms, but PVoutput will not show accurate consumption, import or export.