Western Power · SWIS · Network Connection

Western Power Connection Process

The Major Customer Connection Process (MCCP), technical requirements, studies, costs, and the Critical Project Framework for connecting to Western Power's network.

🔌 MCCP 5-Stage Process 📋 Technical Rules 💰 Connection Costs 🎯 Critical Project Framework
Western Power

Major Customer Connection Process

The MCCP was improved in July 2024 and now averages ~14 months from enquiry to access offer — a 19-month reduction from the 2022 baseline.

⚠️
Applies to new transmission connections. The full 5-stage MCCP below is for new generator connections to Western Power's network. For our sub-5 MW behind-the-meter strategy, most of this process is eliminated — the host site already has a grid connection. You may need to notify WP of the embedded generator and comply with their embedded generation requirements, but you do not go through the full MCCP.
Stage 1 · Enquiry · ~3 months · ~$25K
Connection Options Assessment
Submit your enquiry via the Major Customer Portal (MyWP Projects). Western Power identifies up to 3 connection options with AACE Class 5 cost estimates.

You provide: Enquiry form, contract & payment, critical project evidence.
Stage 2 · Initiation · 6–10 months · $120K–$200K
Network Studies & GPS R0
Steady-state studies, Grid Input Package, and GPS R0 assessment (with AEMO consultation).

You provide: Connection Application, GPS R0/Load Model.
WP delivers: Study Report, Grid Input Package, GPS R0 Assessment, Scope Definition Report.
Stage 3 · Scoping · 4–7 months · $75K–$410K
Concept Design & Cost Estimate
Confirmed scope becomes a concept design with AACE Class 4 or 3 estimate.

You provide: Confirmed line route, payment.
WP delivers: Project Scoping Report with Concept Design.
Stage 4 · Planning · ~4 months · ~$55K
Business Case & Access Offer
Western Power prepares the IWC (Interconnection Works Contract) and ETAC (Electricity Transfer Access Contract).

You provide: Final 3rd-party approvals, payment.
Stage 5 · Execution · Project-specific
Build, Commission & Operate
Dynamic studies, detailed design, procurement, construction, and commissioning.

You provide: Executed Access Offer, Commissioning Test Plan, GPS R1/R2 submissions.
WP delivers: Dynamic/EMT Study Reports, Approval to Operate.
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Self-service options. Steady State Studies (since Feb 2024), GPS & Model Assessment (since Apr 2024), and upcoming Dynamic RMS Wide Area Studies and Customer-Led Design & Construct can reduce costs and accelerate timelines.
Technical Requirements

Studies & Design Principles

Five Connection Design Principles

# Principle Key Requirements
1 System Security Must not affect power system security or other customers. A fault on your side of the CMS must not disconnect others.
2 Generation Planning Loss of power infeed ≤ 400 MW limit. Max ~150 MW per busbar section (300 MW per site). One user per busbar section.
3 Protection Protection systems must be compatible with Western Power and comply with Technical Rules.
4 Network Compatibility Must not hinder future network development (TSP, WoSP) or access by other users.
5 Metering & Ownership Compliant with Technical Rules 3.2.2 and Metering Code. Generator CMS preferably user-owned.

Steady-State Studies (PowerFactory)

Using the publicly releasable SWIS Base Model in DIgSILENT PowerFactory, these studies assess:

  • Thermal loading — Elements must not exceed ratings under N-0, N-1, N-1-1
  • Voltage range — Maintained between 90% and 110% of nominal
  • Voltage step — Infrequent switching limited to -10% / +6%
  • Merit Order Maximum, Minimum, and Shoulder load conditions (20+ study cases)

Generator Performance Standards (GPS)

R0

GPS R0 — Initial Model

Submitted during Initiation. AEMO consulted. Dynamic model assessed for WEM Rules compliance.

R1

GPS R1 — Refined Model

Validated during Execution. Test procedures submitted. AEMO reviews and validates results.

R2

GPS R2 — Final Validation

Post-commissioning. Model updates and on-site validation. Required for Approval to Generate.

💡
Sub-5 MW GPS simplification. The full R0/R1/R2 GPS process applies primarily to transmission-connected generators. For sub-5 MW embedded generators operating behind-the-meter, GPS requirements are typically reduced or waived entirely. You must still comply with the host site's protection settings and Western Power's embedded generation technical requirements.
Priority

Critical Project Framework

Since June 2024, the CPF identifies projects essential to WA's emission reduction and grid reliability. Critical status prioritises allocation of Western Power resources — it does not fast-track connections.

🎯

1. Strategic Alignment

Impact on stability & security. Alignment with TSP, NOM, and government initiatives (ESOO, NCESS, CIS).

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2. Customer Readiness

Secured land, financial readiness, procurement, technical resources, environment & heritage approvals, risk management.

📝

3. Readiness Declaration

Completed checklist and declaration signed by a Director or Senior Executive of your organisation.

📌
Applies to. All transmission connections (Load, Generator & BESS) within the SWIS seeking a new or modified connection to Western Power's network.
Budget

Indicative Costs — WP Connection Process

All Western Power time is cost-recoverable based on actuals. These are from the February 2026 Connection Process Overview. Note: these costs apply to new WP connections — our BTM strategy avoids most of them.

Stage Cost (excl. GST) Timeline
Enquiry $25,000 3 months
Initiation $120K – $200K 6 – 10 months
Scoping $75K – $410K 4 – 7 months
Planning $55,000 4 months
Execution Project-specific Project-specific
💰
Additional costs (WP connection only). GPS modelling & dynamic studies (consultant fees) · Environmental & heritage approvals · Land access & easements · Equipment procurement & construction · AEMO registration fees · Reserve Capacity Security · CAG fees if behind a shared network constraint.
✅
BTM approach eliminates WP costs. Deploying behind-the-meter at an industrial site with an existing 11kV connection means you do not go through the MCCP. Total WP costs avoided: $275K–$1.5M+. Your only costs are equipment, site works, 11kV switchgear, and council permits (~$30K–$80K).
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