BESS GADS Performance

Bazefield Core automates NERC GADS Storage Group Performance tracking for Battery Energy Storage Systems (BESS). Rather than requiring operators to manually assign operating states, a built-in Script Service job continuously reads device-level status signals, applies NERC priority rules, and writes the resulting allocations — ready for direct export to NERC's GADS submission tool.

Regional applicability: NERC GADS reporting applies to North American generation owners and operators subject to NERC Reliability Standards or voluntary GADS reporting programs. For a full introduction to GADS in Bazefield, see GADS Reporting in Bazefield.

How it works

Bazefield models a BESS plant using a two-level hierarchy: each GADS Energy Storage Group (the NERC reporting unit) contains one or more Power Conversion System (PCS) child objects. Each PCS carries a set of seven boolean EVENT-* data points that are continuously updated from the SCADA/historian to reflect the current operating state of that unit.

The GADS Energy Storage Performance Script runs on a recurring schedule against every GADS Energy Storage Group in the system. On each run it:

1. Reads the EVENT-* boolean tags for all PCS children of the group over the configured look-back window.

2. Applies NERC priority rules to determine the dominant state at each time step (see Operating states and priority below).

3. Creates or updates allocations in the ESS_GADS allocation type on the storage group, segmented by NERC category (e.g. Charging/ChgHrs, Forced/StorageFOH).

These allocations are what the GADS Reporting application reads when generating the monthly Performance submission file. No manual time-booking is required — the script keeps the allocation record continuously up to date.

Script schedule

The script is installed as a per-object Script Service job and runs on every GADS Energy Storage Group object independently.

Note: The cron expression is 25 10 */3 1/1 * ? * — runs at 10 minutes 25 seconds past the hour, every 3 hours. The midnight reconciliation is triggered by checking whether the run time falls at hour 0.

Operating states and priority

Each PCS unit reports its state through boolean data points. When multiple states are simultaneously active — or when different PCS units within a group report different states — the script resolves the conflict using the NERC-aligned priority table below. Lower priority number wins.

Priority resolution: Charging and Discharging share priority 1 because they are mutually exclusive operating states. When Forced, Maintenance, and Planned all share priority 5, the first active signal in the time window is used. Outage states only take effect when none of the higher-priority operational or idle states are active.

Data model components

All components listed below are installed by the Core GADS package.

Calculated points on the storage group

The Core GADS ESG Calcs template installs three aggregate calculated points on the storage group that feed the performance export:

Prerequisites for submission

Before generating a BESS GADS Performance submission from the GADS Reporting application, confirm the following are in place:

• Each BESS plant has a GADS Energy Storage Group object with storageGroupID, plantID, rated capacity, and time zone attributes populated.

• Child PCS objects are linked to the storage group via the GADSStorageGrpId attribute.

• The Core GADS ESG Calcs point template is installed on the storage group, and all seven EVENT-* boolean tags are mapped to the appropriate SCADA/historian source points for each PCS.

• The GADS Energy Storage Performance Script is active in Script Service and has completed at least one successful run. Verify in the Script Service log that allocations were written without errors.

• The ESS_GADS allocation type is present on the storage group and contains allocations covering the reporting month.

• Historian data for ChargingEnergy and DischargingEnergy on each child PCS is available and flowing.

Generating the submission

Once the script has populated the ESS_GADS allocations, use the GADS Reporting application to export the monthly performance file. The application reads the ESS_GADS allocation hours and the calculated energy totals from the storage group, and formats them for direct submission to NERC.

For the step-by-step export workflow, see GADS Energy Storage Performance Submission.

For BESS event reporting (outage cause codes, system description, event files), see GADS Energy Storage Event Submission.

Troubleshooting