Hi there,
It would be great if someone could clarify whether to use a Utility Meter or not. My battery inverter (AlphaESS) exposes only battery power (W) every 10 seconds, not energy (kWh), and further, the battery power shows positive if discharging and negative if charging. All good. Fix needed.
So, I created two sensors, lets call them CHARGING_POWER and DISCHARGING_POWER which are positive numbers only, and flatline at zero. So instead of charging at 2000W showing -2000, I have CHARGING_POWER of 2000 and DISCHARGING_POWER at 0. On the flip side, if discharging at 1500W then DISCHARGING_POWER will be 1500 and the CHARGING_POWER will be 0.
I then push them into Reimann sums. To be honest, all this is working well:
So 2.56kWh is roughly what has been discharged today so far, and 0.6kWh what has gone in from solar. It is just a coincidence that the current power draw is 2560W 
I push those two Reimann sums into the appropriate parameters on the energy dashboard:
And the chart is accurate:
The integrals I have set up for hourly. I suppose my questions are, do Integrals reset to zero each hour if configured for hourly, and further readings help populate that hour, or is it just a sampling range? Further, does the Energy Dashboard handle the amount of kWh for each day, or do I need to push the Reimanns into Utility Meters which forcibly reset kWh to zero daily and use those utility meters in the Energy Dashboard?
Many thanks
Dan