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The Energy Storage System (ESS) nodal data provides timestep results for battery storage operations, including state of charge, charge/discharge power flows, efficiency losses, and dispatch algorithm behavior. This data is only available when energy storage is included in the prediction.

Description of Nodal Data Parameters

ParameterUnitsDescription
MonthCalendar month of the timestep (1-12)
DayDay of the month for the timestep
HourHour of the day for the timestep (0-23)
IsTargetHourBoolean indicating whether the timestep falls within the configured discharge target period
TotalPowerGeneratedAfterAvailabilityLossWTotal PV power available after availability losses, used to determine excess power for charging
BatteryMaxCapacityWhCurrent maximum usable energy capacity of the battery after calendar and cycle degradation
BatteryDCRTECurrent DC round-trip efficiency of the battery after calendar and cycle degradation
BatterySOCWhBattery state of charge at the end of the timestep, representing stored energy
BatteryDCPower_4WDC power flow at the battery, positive for charging and negative for discharging
BatteryACCharge_3WAC power flowing into the battery system during charging, measured at the inverter AC terminals
BatteryACDischarge_3WAC power flowing out of the battery system during discharging, measured at the inverter AC terminals
Battery_ACCharge_2WAC power drawn from the PV system for battery charging, measured at the MV transformer secondary
Battery_ACDischarge_2WAC power delivered by the battery to the grid, measured at the MV transformer secondary
BatteryRTE_CycleDegCumulative round-trip efficiency degradation from charge/discharge cycling
BatteryRTE_CalendarDegCumulative round-trip efficiency degradation from calendar aging
UsableEnergyCap_CycleDegCumulative usable energy capacity degradation from charge/discharge cycling
UsableEnergyCap_CalendarDegCumulative usable energy capacity degradation from calendar aging
PV_exceeding_interconnect_6WPV power exceeding the interconnection limit, available for battery charging under LGIA Excess algorithm
AvailableExcesstoCharge_4WMaximum power available to charge the battery from excess PV production, after inverter and transformer losses
AvailableCapacitytoDischarge_6WMaximum power available for battery discharge at the point of interconnection, considering both storage and grid constraints
AvailableCapacitytoDischarge_4WMaximum power available for battery discharge at the DC side, after accounting for inverter efficiency
PVMVXfmrOutputAdjusted_1WPV MV transformer output adjusted for power diverted to battery charging
PVMVXfmrOutputAdjusted_1_LGIALimitedWPV MV transformer output after applying interconnection limit constraints
PVPVSCombined_7WCombined PV and storage power output at the MV level, prior to HV equipment losses
AvailableCapacitytoChargefromNonExcess_4WMaximum power available to charge the battery from non-excess PV production, used in Energy Available algorithm
InverterEfficiencyLossWPower loss from battery inverter inefficiency during the timestep
MVTransformersLossWPower loss in the storage system MV transformer during the timestep
HVACLossWPower consumption for battery thermal management (HVAC) systems
DCRoundtripEfficiencyLossWPower loss from battery DC round-trip efficiency during charging operations