Help & Glossary

Everything you need to understand the Connection Intelligence Platform — scoring methodology, connection strategies, key terms, and data sources.

Connection Strategies

Lane A vs Lane B

LANE AFlexible Envelope

Connect at full capacity but with a dynamic operating envelope. The BESS can charge/discharge at full power when network conditions allow, but automatically curtails when the network is constrained.

How it works

Uses runback systems and real-time monitoring. AusNet sets operating limits that change dynamically based on network loading.

Speed

Faster to negotiate if AusNet accepts the envelope approach, but requires more sophisticated control systems and comms infrastructure.

Best for

Sites with good network headroom most of the time. The BESS runs unconstrained 80–90 % of the year and curtails only during peak periods.

LANE BTime-to-Deploy First

Connect at a deliberately conservative capacity first (e.g., 1.25 MW instead of 5 MW) to reduce study burden and get energised faster. Then expand later.

The approach

"Submit 1.25 MW request but with lead-in feeder/ACR capable of 5 MW. Build and commission at 1.25 MW. Then run normal modelling process and expand to 5 MW once approved."

Speed

Fastest path to energisation. Reduced study scope means fewer revision cycles and shorter AusNet assessment.

Best for

Sites where getting operational quickly matters more than day-one full capacity. Start earning revenue while the expansion studies proceed in parallel.

Scoring Methodology

How substations are ranked

100

Feasibility Score

0 – 100

How likely is this substation to receive a connection offer?

Thermal headroomVoltage constraintsProtection complexityREFCL impactFault levels

Higher = more feasible. A score above 65 indicates a strong candidate.

100

Acceleration Score

0 – 100

How fast can we get from application to offer?

Data availabilityStudy complexityExpected revision cyclesConsultant availability

Higher = faster. Substations with existing Greenwood data packs score significantly higher.

100

Capex Risk Score

0 – 100 · ⚠ inverse scale

How much will augmentation and connection works cost?

Conductor upgrades neededProtection equipmentREFCL requirementsCivil worksContestable works

Higher = MORE expensive/risky (inverse — low is better). A high score means higher expected capital expenditure.

100

Commercial Score

0 – 100

What's the revenue potential vs cost?

Arbitrage opportunityFCAS revenueNetwork support paymentsPayback periodExport constraints

Higher = better commercial case. Factors in both revenue upside and cost downside.

Σ

Overall Rank

Weighted combination of all four scores

The overall rank is a weighted composite that balances feasibility, speed, cost risk, and commercial viability. Capex risk is inverted (lower cost = higher contribution). The weights are calibrated based on Greenwood's strategic priorities — getting deployable sites first, with a preference for strong commercial cases.

Key Terms Glossary

21 terms

ZSS / Zone Substation
The distribution substation that steps voltage down from 66 kV to 22 kV. This is where BESS projects typically connect.
Feeder
The 22 kV power line that radiates from a zone substation to supply customers. Each ZSS has 3–10 feeders.
REFCL
Rapid Earth Fault Current Limiter. Installed at some Victorian substations in bushfire-prone areas. Adds significant cost and complexity to connections.
Nameplate MVA
The total transformer capacity of a zone substation.
Peak Demand
The maximum power draw recorded at the substation.
Utilisation
Peak demand ÷ nameplate capacity. Over 100 % means the substation is overloaded.
Reverse Flow
When solar generation exceeds demand, power flows backwards through the substation. Measured in half-hourly intervals.
Export Constraint
MW of solar generation "at risk" — the amount that may need to be curtailed due to network limits.
Hosting Capacity
How much additional generation the network can accept without upgrades.
SINCAL
The network modelling software used by AusNet. Steady-state studies must be done in SINCAL.
Steady-State Study
The first network study required — models power flow, thermal loading, and voltage under various scenarios.
SOP 11-16
AusNet's Standard Operating Procedure for embedded generator protection requirements.
DFA
Distribution Feeder Automation — automatic network reconfiguration during faults. BESS must be modelled for DFA scenarios.
NER Chapter 5A
The National Electricity Rules chapter governing negotiated connections (which 1.5–4.99 MW projects fall under).
AEMO Exemption
Projects under 5 MW nameplate can be exempt from AEMO generator registration.
RIT-D
Regulatory Investment Test for Distribution. Triggered when network augmentation exceeds $7 M. Can delay projects significantly.
DSA
Development Services Agreement (with Ampyr). The contract under which Greenwood develops sites.
Data Pack
The network data package AusNet provides for modelling. Currently taking 58–85 business days to deliver.
Connection Offer
The formal offer from AusNet specifying connection terms, costs, and conditions. The goal of the entire process.
Data Confidence
How reliable the data is — "high" means from AusNet's System Limitation Report, "medium" from voltage compliance data, "low" from estimates.
Firm Summer Capacity (N-1)
The substation's capacity with one transformer out of service. The real constraint during peak demand.

AusNet Connection Process

From site ID to energisation

Realistic timelines calibrated from Greenwood's actual experience across 11 active projects.

Step 1

Site identification & land lease

Variable

Identify target zone substations, secure land near the substation, execute lease.

Step 2

Pre-feasibility request to AusNet

~1 week to submit

Formal request letter to AusNet Connections describing the proposed BESS, capacity, and connection point.

Step 3

Pre-feasibility response

~4–6 weeks

AusNet provides high-level indication of constraints, REFCL status, and likely study requirements.

Step 4

Data pack request & delivery

~58–85 business days

Request network data (load traces, SINCAL model, protection settings). This is the single biggest bottleneck. Based on Greenwood's 11-project experience.

Step 5

Commission steady-state study

~6–10 weeks · $15–25 k

Engage a consultant (Powerplant Engineering, APD, or Hanna) to build a SINCAL model and run scenarios.

Step 6

Submit study to AusNet

~1 week

Formal submission of completed network study for AusNet technical review.

Step 7

AusNet review + issues tracker

~4–8 weeks per round

AusNet assigns a reviewer who logs issues in a tracker. Expect detailed technical questions and requested changes.

Step 8

Revision cycles

~2–3 rounds

Back-and-forth between consultant and AusNet. The #1 cause of delays. Each round takes 4–8 weeks.

Step 9

Power quality + dynamic studies (if needed)

~4–8 weeks · $10–20 k

Required for larger or more complex connections. Harmonic analysis, transient stability, PSCAD modelling.

Step 10

Connection application

~2 weeks to prepare

Formal NER Chapter 5A connection application with all supporting documentation.

Step 11

Assessment period

65 biz days (published) · longer in practice

AusNet's formal assessment window. Can extend if they raise further issues or require more studies.

Step 12

Connection offer

Milestone 🎯

AusNet issues a formal connection offer specifying terms, costs, protection requirements, and conditions.

Step 13

Offer acceptance + detailed design

~4–8 weeks

Review offer, negotiate terms if needed, engage detailed design consultants for protection and metering.

Step 14

Construction + commissioning

~12–20 weeks

Civil works, BESS installation, switchgear, HV cabling, transformer, comms infrastructure.

Step 15

Energisation

Milestone ⚡

Final inspections, protection relay commissioning tests, AusNet witness testing, and energisation.

Data Sources

Provenance & confidence

AusNet System Limitation Report 2025

high
26 ZSS

Detailed thermal, voltage, and protection data for constrained substations. Primary source for scoring.

AusNet Voltage Compliance CSV

medium
66 ZSS

Voltage compliance data across the AusNet distribution network. Broader coverage but less depth.

AusNet ZSS Load Trace 2025

high
25 ZSS

Half-hourly metering data enabling load profiles, utilisation analysis, and reverse flow detection.

AusNet DAPR 2025

high
Full network

Distribution Annual Planning Report: export constraints, investment plans, demand forecasts.

Victorian Terminal Station Demand Forecasts (AEMO)

medium
All terminal stations

10 % POE and 50 % POE demand forecasts out to 2030. Used for growth projections.

Greenwood Project Emails & Comms

high
11 projects

Real-world timeline data, consultant costs, AusNet response times, and issue patterns from Greenwood's active projects.