> ## 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                                                  |