> ## Documentation Index
> Fetch the complete documentation index at: https://docs.plantpredict.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Energy Storage Nodal Data

> Detailed parameters in the Energy Storage System nodal data export

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

| Parameter | Units | Description |
| - | - | - |
| Month | — | Calendar month of the timestep (1-12) |
| Day | — | Day of the month for the timestep |
| Hour | — | Hour of the day for the timestep (0-23) |
| IsTargetHour | — | Boolean indicating whether the timestep falls within the configured discharge target period |
| TotalPowerGeneratedAfterAvailabilityLoss | W | Total PV power available after availability losses, used to determine excess power for charging |
| BatteryMaxCapacity | Wh | Current maximum usable energy capacity of the battery after calendar and cycle degradation |
| BatteryDCRTE | — | Current DC round-trip efficiency of the battery after calendar and cycle degradation |
| BatterySOC | Wh | Battery state of charge at the end of the timestep, representing stored energy |
| BatteryDCPower\_4 | W | DC power flow at the battery, positive for charging and negative for discharging |
| BatteryACCharge\_3 | W | AC power flowing into the battery system during charging, measured at the inverter AC terminals |
| BatteryACDischarge\_3 | W | AC power flowing out of the battery system during discharging, measured at the inverter AC terminals |
| Battery\_ACCharge\_2 | W | AC power drawn from the PV system for battery charging, measured at the MV transformer secondary |
| Battery\_ACDischarge\_2 | W | AC power delivered by the battery to the grid, measured at the MV transformer secondary |
| BatteryRTE\_CycleDeg | — | Cumulative round-trip efficiency degradation from charge/discharge cycling |
| BatteryRTE\_CalendarDeg | — | Cumulative round-trip efficiency degradation from calendar aging |
| UsableEnergyCap\_CycleDeg | — | Cumulative usable energy capacity degradation from charge/discharge cycling |
| UsableEnergyCap\_CalendarDeg | — | Cumulative usable energy capacity degradation from calendar aging |
| PV\_exceeding\_interconnect\_6 | W | PV power exceeding the interconnection limit, available for battery charging under LGIA Excess algorithm |
| AvailableExcesstoCharge\_4 | W | Maximum power available to charge the battery from excess PV production, after inverter and transformer losses |
| AvailableCapacitytoDischarge\_6 | W | Maximum power available for battery discharge at the point of interconnection, considering both storage and grid constraints |
| AvailableCapacitytoDischarge\_4 | W | Maximum power available for battery discharge at the DC side, after accounting for inverter efficiency |
| PVMVXfmrOutputAdjusted\_1 | W | PV MV transformer output adjusted for power diverted to battery charging |
| PVMVXfmrOutputAdjusted\_1\_LGIALimited | W | PV MV transformer output after applying interconnection limit constraints |
| PVPVSCombined\_7 | W | Combined PV and storage power output at the MV level, prior to HV equipment losses |
| AvailableCapacitytoChargefromNonExcess\_4 | W | Maximum power available to charge the battery from non-excess PV production, used in Energy Available algorithm |
| InverterEfficiencyLoss | W | Power loss from battery inverter inefficiency during the timestep |
| MVTransformersLoss | W | Power loss in the storage system MV transformer during the timestep |
| HVACLoss | W | Power consumption for battery thermal management (HVAC) systems |
| DCRoundtripEfficiencyLoss | W | Power loss from battery DC round-trip efficiency during charging operations |


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