How to apply PV generated electricity to one of multiple electricity tariffs?

edit

Fernanda Schuch of DesignBuilder support provided a solution through EMS scripting. The EMS included (3) sensors:

• meter Electricity:Facility
• meter ResidentialMeter (previously created using meter:custom object)
• meter ElectricityProduced:Facility (which I changed to output variable, *,Inverter AC Output Electricity Energy, for capturing post inverter energy at the net meter)

Then a simple program was written to set the

CommercialElectric (global variable) = Electricity:Facility - ResidentialMeter - Inverter AC Output Electricity Energy.

Here is a copy of the code for reference:

EnergyManagementSystem:Sensor,
  FacilityElectric,
  ,
  Electricity:Facility;

EnergyManagementSystem:Sensor,
  ResidentialElectric,
  ,
  130Bank_ResidentialElecMeter;

EnergyManagementSystem:Sensor,
  SolarGenerated,
  EXAMPLE INVERTER - SIMPLE,
  Inverter AC Output Electricity Energy;

EnergyManagementSystem:GlobalVariable,
  CommercialElectric;

EnergyManagementSystem:Program,
  CalculateCommercialNet,
  Set CommercialElectric = FacilityElectric - ResidentialElectric - SolarGenerated;

EnergyManagementSystem:ProgramCallingManager,
  RunCalcCommercial,
  EndOfZoneTimestepBeforeZoneReporting,
  CalculateCommercialNet;

EnergyManagementSystem:OutputVariable,
  CommercialElectric,
  CommercialElectric,
  Summed,
  ZoneTimeStep,
  ,
  Joules;

Output:Variable,*,CommercialElectric,Hourly;
Output:Variable,*,CommercialElectric,Daily;
Output:Variable,*,CommercialElectric,Monthly;
Output:Variable,*,CommercialElectric,RunPeriod;

Meter:Custom,
CommercialElecMeter,
Electricity,
,
CommercialElectric;

Thanks