Battery dispatch non-conformance can arise when the power offered to the market no longer matches the battery's operating capability, when plant controls change the requested output, or when the dispatch and measurement systems disagree. A battery's response speed addresses only one part of that chain. Available energy, charge and discharge limits, the required ramp and reliable feedback also determine whether the plant follows its dispatch instruction.
For battery projects in Australia's National Electricity Market (NEM), the practical question is where the requested power and actual output first separate. That distinction determines whether the problem belongs to availability information, battery limits, plant control or telemetry.
What AEMO Assesses When a Battery Misses Its Target
AEMO's Dispatch Procedure, effective 1 October 2026, describes conformance monitoring for scheduled bidirectional units and other scheduled resources. It uses dispatch targets and SCADA quantities, with defined error triggers and escalation processes. An Off-Target indication and a formal Non-Conforming declaration represent different stages; an isolated gap on a trend chart does not establish the latter.
The assessment also accounts for specified regulation FCAS movement. The applicable calculation depends on the resource and conformance arrangement. A universal percentage tolerance, or a comparison between one inverter reading and an energy target, cannot replace that assessment.
Why Available Battery Power Changes During Dispatch
Stored Energy and Discharge Power Answer Different Questions
State of charge (SOC) describes the battery's charge level. Dispatch also depends on how much power it can deliver now. A battery may retain substantial stored energy while temperature, cell-voltage limits, disconnected racks or converter capability restrict its output.
For example, consider a hypothetical 10 MW / 20 MWh installation whose available discharge power has fallen to 6 MW. An 8 MW request exceeds its present capability even if enough usable energy remains to sustain that output in energy terms. Increasing the requested setpoint cannot recover the unavailable 2 MW. This illustrates a capability shortfall, not an AEMO conformance determination.
Available discharge energy and available discharge power therefore need separate treatment. The first limits how long a schedule can continue; the second limits the output that can be reached. Equipment outages, degradation allowances and operating reserves can change the relationship between nameplate MWh and energy available for dispatch.
Charging and Discharging Have Different Limits
A battery approaching its upper SOC or cell-voltage limit may have little charging capability while retaining discharge capability. Near its lower operating boundary, the opposite can occur. Charge and discharge availability cannot be inferred from one symmetric MW rating.
A concrete equipment example appears in SMA's Solbank battery-interface documentation, which distinguishes permitted charging current, permitted discharging current and remaining energy in each direction. These are configuration-specific signals, but they illustrate why an SOC percentage alone leaves important dispatch limits unresolved.
How a Dispatch Command Becomes Grid-Side Power
The market instruction passes through the site's control architecture before it becomes electrical output. The plant controller allocates power among available equipment; the PCS executes the resulting commands within its limits and the battery's limits. Grid-side measurements then report the outcome.
The Darlington Point Energy Storage System project report documents this separation in a real 25 MW / 50 MWh Australian installation. Its gateway receives AEMO dispatch information, the site controller regulates plant output using a control meter, and equipment controllers manage the individual units. This is the architecture of that project; controller names and responsibilities vary between installations.
During a shortfall, comparing the following records identifies where the power request changes. Their units, power direction and timestamps must agree.
| Observed Mismatch | What It Can Indicate | Information That Separates the Causes |
|---|---|---|
| The external target changes, but the plant's accepted command does not. | A stale instruction, another control mode or a controller-imposed restriction. | Instruction receipt time, active command source and the controller's limiting status. |
| The accepted command increases, but PCS output stops below it. | Battery or converter limits, unavailable equipment, or command execution problems. | Live charge/discharge limits, connected equipment, PCS state and fault or derating records. |
| PCS output follows, but the registered grid-side quantity differs. | A different electrical boundary, losses, auxiliaries or a measurement problem. | Meter location, transformer and auxiliary arrangement, scaling and simultaneous measurements. |
| Local measurements change, but the remote SCADA value stays fixed or arrives late. | Stale telemetry, timestamp errors or a communications-path problem. | Source timestamps, data-quality flags and gateway transmission records. |
These patterns narrow the investigation; a trend alone does not prove the cause. The BMS, PCS and EMS interface definitions establish the meaning of commands, operating limits and status signals used in this comparison.
How the Dispatch Trajectory Determines Delivered Energy
AEMO's procedure specifies uniform ramping towards the end-of-interval target when no ramp rate is supplied directly, subject to the stated conditions and required services. The target MW therefore needs to be read together with the applicable trajectory.
Illustrative energy calculation: assume net export starts at zero and rises linearly to 40 MW over exactly five minutes, with no regulation movement. Average power is 20 MW, so the delivered energy is:
Energy = (0 MW + 40 MW) ÷ 2 × (5 ÷ 60 hours) = approximately 1.67 MWh.
Holding a constant 40 MW for those five minutes would instead deliver approximately 3.33 MWh. Both profiles end at 40 MW, but they have different energy requirements. These figures are an idealized comparison, not a dispatch instruction, settlement calculation or project result.
Battery-side energy must also cover the conversion losses and auxiliaries supplied from that energy path. Across consecutive intervals, the actual power trajectory determines SOC movement. A schedule based only on end-point targets can misrepresent the energy remaining for later instructions.
What Dispatch Deviations Can Cost a Battery Project
Energy Delivery and Operational Constraints
Delivering less or more energy than intended changes the plant's commercial position. The effect depends on price, direction of operation and the relevant contracts. A shortfall during charging has different energy and SOC consequences from a shortfall during export.
AEMO can also impose a non-conformance constraint under its procedure. Restricted operation can reduce subsequent dispatch opportunities. The effect on a particular project requires its actual dispatch, price and contractual data.
Frequency Performance Payments
Frequency Performance Payments (FPP) commenced on 8 June 2025. The arrangements assign positive and negative financial outcomes according to eligible facilities' contribution to frequency performance and allocate regulation FCAS costs. They are not a fixed charge for each missed energy target.
Consequently, dispatch tracking and frequency performance need separate interpretation. Identifying an energy-target deviation does not establish the sign or amount of the facility's FPP outcome.
FCAS Delivery and Enforcement
FCAS offers must reflect deliverable capability. Once enabled, a service must be delivered in accordance with the applicable dispatch instructions and service requirements. On 11 November 2026, the Australian Energy Regulator reported that EnergyAustralia had paid AUD 750,000 across 10 infringement notices. The allegations concerned four BESS and failures during 2023 and 2024 to fulfil FCAS offers or comply with FCAS dispatch instructions. Payment of an infringement notice does not constitute an admission of a contravention.
This was an FCAS enforcement matter, not a universal penalty schedule for energy-target deviations. For a battery combining energy trading and frequency services, the available operating range has to accommodate both duties. NEM dispatch co-optimises energy and FCAS. If actual export capability falls below the capability reflected in dispatch inputs, the plant may lack sufficient headroom to deliver an enabled raise service.
What a Dispatch Demonstration Needs to Establish
A PCS power-step test establishes the response of the tested equipment under the test conditions. Whole-plant dispatch also depends on the installed gateway, plant controller, available battery blocks and registered telemetry path. Those interactions become visible when a changing instruction is followed through to measured plant output.
The useful result is a time-aligned record explaining the delivered trajectory and any restriction. If a battery limit falls, the record needs to distinguish the original instruction, the accepted command, the active limit and actual output. Without that separation, a legitimate protective restriction can look like a slow controller, while a stale remote value can look like a battery that never responded.
Commissioning at partial capacity also leaves less equipment and energy available than the completed plant. Commercial availability and operating instructions need to reflect that stage. A successful demonstration at one SOC and power level establishes performance for those conditions; the intended operating range requires its own assessment.
Matching Battery and PCS Equipment to the Plant Control Scope
For a utility-scale project, battery energy, PCS power and plant-level control responsibilities need to be specified together. The battery defines its permitted operating envelope; the power-conversion equipment translates that capability into AC output; the plant's dispatch arrangement coordinates the equipment with the required service.
Polinovel supplies containerized BESS in integrated and separate-unit arrangements, alongside PCS containers with step-up transformer integration. Equipment selection covers the required discharge window, battery voltage range, AC power and site electrical interfaces. For a NEM project, market registration, plant controls, telemetry and service qualification remain project-specific responsibilities to allocate with the EPC, operator and relevant specialists.