By AGILE Consulting Engineers, Solar PV and Battery Energy Storage Systems (BESS) specialists.
Most Battery Energy Storage System (BESS) projects that fail to earn their expected virtual power plant (VPP) revenue were not let down by the battery. They were let down by decisions made months before commissioning, in the inverter selection, the metering specification, or a registration step nobody assigned to an owner. Retrofitting VPP-readiness after a system is built is possible, but it almost always costs more than specifying it correctly the first time. This is a working checklist, not a sales pitch, for what actually needs to happen before a BESS asset is genuinely ready to be dispatched by an aggregator.
Table of Contents
- VPP-Readiness Starts at the Design Table
- PCS and Inverter Selection
- Telemetry and Metering Specification
- DER Register Compliance
- MASS Readiness for FCAS Participation
- Cyber Security Basics
- Commissioning: FAT and SAT Milestones
- Choosing an Aggregator or Platform
- What to Do Next
- FAQ
VPP-Readiness Starts at the Design Table
A VPP aggregates distributed energy resources (DER), batteries, rooftop solar photovoltaic (PV) systems, and other flexible loads or generation, through an energy management system (EMS) or distributed energy resource management system (DERMS), so they can be dispatched collectively into wholesale or Frequency Control Ancillary Services (FCAS) markets in the National Electricity Market (NEM), overseen by the Australian Energy Market Operator (AEMO). Getting a BESS asset ready to participate is not a single certification you obtain at the end. It is a set of design and procedural decisions that need to be locked in from the earliest stage of the project, because several of them, particularly around the power conversion system (PCS) and metering, are expensive or impossible to change after installation.
PCS and Inverter Selection
The PCS, the inverter that converts the battery’s stored energy to grid-compatible alternating current and back, is the single component with the most influence over what a BESS asset can later do commercially. In Australia, grid-connected inverters must comply with AS/NZS 4777.2, which sets performance and safety requirements including anti-islanding protection, voltage and frequency ride-through behaviour, and power quality, while AS/NZS 4777.1:2024, the current installation standard, sets out how the inverter energy system is connected and configured, including provision for newer technologies such as vehicle-to-grid arrangements. Beyond baseline compliance, the PCS needs to support remote setpoint control at a response speed consistent with the FCAS categories the project intends to target, and it needs an open, well-documented communication protocol, whether Modbus, a SunSpec-compliant register map, or a documented proprietary interface, so an aggregator’s DERMS can actually integrate with it without a bespoke and fragile workaround. Selecting a PCS purely on capital cost, without checking its control response characteristics and communication support, is one of the most common and hardest to reverse mistakes in a VPP-bound project.
Telemetry and Metering Specification
Metering and telemetry need to be specified with the target market service in mind, not as an afterthought once the electrical design is finished. Revenue-grade metering that meets AEMO’s market metering requirements is generally required for wholesale settlement purposes, and FCAS participation, particularly in the faster response categories, comes with its own measurement resolution expectations under AEMO’s Market Ancillary Service Specification (MASS). Beyond the metering hardware itself, the data path matters just as much: how telemetry reaches the aggregator’s supervisory control and data acquisition (SCADA) or DERMS platform, what happens during a communications outage, and whether the local site network has enough redundancy to avoid dropouts that would show up as missed dispatch instructions. Specifying telemetry architecture alongside the electrical design, rather than bolting it on afterwards, avoids a second round of cabling and configuration work later.
DER Register Compliance
Registration of the equipment on AEMO’s DER Register is a compliance step that is easy to overlook because it sits with the installer rather than the design engineer, but it is a genuine prerequisite for a smooth connection and, in most jurisdictions, for evidencing that a battery installation is properly recognised by the network. Registration typically needs to occur within a defined window of commissioning and requires detailed equipment information, including inverter manufacturer, model and serial numbers. Several networks have tightened enforcement of this requirement in the past two years, including transitional arrangements in New South Wales that lapsed in mid-2025, after which evidence of DER Register listing became a firm precondition for certain connection approvals. Building DER Register submission into the commissioning checklist, with a named responsible party, avoids a late-stage scramble that can delay energisation.
MASS Readiness for FCAS Participation
If a project intends to target FCAS revenue, MASS readiness needs to be treated as a distinct workstream from general grid connection compliance. AEMO’s current MASS, in effect since October 2023, sets out the metering, verification and performance testing requirements for each FCAS category, including the very fast raise and lower categories introduced at that time. Practically, this means the project needs a verification test plan agreed with AEMO or the aggregator managing the registration, metering that meets the resolution requirements of the target category, and a realistic understanding of how long the verification process takes, since it is not instantaneous and should be built into the project’s revenue-ramp assumptions rather than assumed from day one of operation.
Cyber Security Basics
A remotely dispatchable BESS asset is, by definition, a remotely accessible piece of grid infrastructure, and it should be treated with a baseline level of cyber security discipline regardless of project size. This does not require enterprise-grade infrastructure for a modest commercial battery, but it does mean avoiding default credentials on site networking equipment, segmenting the site’s operational technology network from general site Wi-Fi or corporate connections, and confirming that the aggregator’s own platform participates in recognised assessment programs such as the Australian Energy Sector Cyber Security Framework (AESCSF), which AEMO coordinates for the sector. Asking an aggregator directly about their AESCSF maturity level, or equivalent independent assessment, before signing is a reasonable and increasingly standard due diligence step.
Commissioning: FAT and SAT Milestones
Factory acceptance testing (FAT) and site acceptance testing (SAT) are where VPP-readiness gets proven rather than assumed. FAT, conducted before equipment leaves the manufacturing or integration facility, should confirm that the PCS and battery management system (BMS) respond correctly to the control signals the aggregator’s platform will actually send, not just that the unit powers on and cycles correctly in isolation. SAT, conducted after installation, should validate the same control and telemetry behaviour under real site network conditions, including a deliberate test of what happens during a simulated communications dropout. Building specific VPP dispatch and telemetry tests into both FAT and SAT protocols, rather than treating them as generic commissioning steps, is what turns “the battery works” into “the battery is dispatchable.”
Choosing an Aggregator or Platform
The final piece is choosing which aggregator or platform will actually operate the asset commercially. This should be assessed on interoperability with the PCS and BMS actually installed, transparency of dispatch and settlement reporting, a demonstrated track record of MASS-compliant FCAS registrations if that is the target revenue stream, and clear contractual terms around capacity guarantees and how underperformance risk is allocated. These criteria matter more than headline revenue estimates, which are only as good as the platform’s actual ability to dispatch the fleet reliably.
What to Do Next
Working through this checklist properly, ideally before the PCS is ordered, is the point where a technical review can save months of rework later. We have helped project teams work through exactly this kind of VPP-readiness assessment before committing to hardware, and it is usually far cheaper to do it at that stage than after the switchboard is closed up.
FAQ
What inverter standard applies to grid-connected batteries in Australia?
AS/NZS 4777.2 sets performance and safety requirements for grid-connected inverters, while AS/NZS 4777.1:2024 is the current installation standard covering how inverter energy systems are connected and configured.
When does a battery system need to be registered on AEMO’s DER Register?
Registration is generally required within a defined window after commissioning and needs detailed equipment information such as inverter manufacturer, model and serial numbers, with several networks now enforcing this as a precondition for connection approval.
Do I need special metering to participate in FCAS?
Yes, FCAS participation, especially in the faster response categories, requires metering that meets the measurement resolution set out in AEMO’s Market Ancillary Service Specification (MASS) for the specific category being registered.
What is the difference between FAT and SAT for a BESS project?
Factory acceptance testing (FAT) validates equipment behaviour, including control and telemetry response, before it leaves the manufacturing or integration facility, while site acceptance testing (SAT) validates the same behaviour on site under real network conditions after installation.
How important is cyber security for a small commercial BESS project?
It matters regardless of project size, since any remotely dispatchable battery is a remotely accessible piece of grid infrastructure, and basic measures like network segmentation and avoiding default credentials should be standard.
What should I look for when choosing a VPP aggregator?
Look for demonstrated interoperability with your specific inverter and battery management system (BMS), transparent dispatch and settlement reporting, a genuine MASS-compliant FCAS track record if relevant, and clear contractual terms on capacity guarantees.
