Hi Paul,
It is related to the
power demand policy. Here in DR the policy about the demand charge is determined either by the last highest peak or the average of the two months with the highest peak registered, whichever is larger will be taken as reference for the rest of the year as fix demand charge.
If a residential/commercial customer install a PV system with a net metering structure, then the same policy stated above apply or......... if the power injected from the PV system is larger then the last one is consider as the fix demand charge for the rest of the year, that's why we need to take care about the power injected to the Grid.
My intention is to control, dynamically, the inverters power output by measuring the load (using the eGauge tool, for example). So, as an example, if at any step the load is 20 kW then the max inverters output power will be limited to 70 kW (70 - 20 = 50 kW) and then the Utility Grid will see only 50 kW injected to its system.
Let me know if you got the idea.
Correction...............I think the time serie "Electricity to/from grid peak (kW)" is already the result of the "System power generated (kW)" minus the "Electricity load (kW)" at least for positive values, correct me if I am wrong. So when I limit the grid interconnection to any value, the reflected result already have the "Electricity load (kW)" subtracted.
Best-
Carlos