Powerlink, Queensland’s state-owned transmission network service provider, plays a central role in Australia’s energy transition. Responsible for developing, operating, and maintaining the state’s high-voltage transmission network, Powerlink enables new generation connections while ensuring the system remains safe, reliable, and cost-effective.
As renewable penetration increases and electrification expands demand, long-term planning has grown significantly more complex. Transmission investments are capital-intensive and discrete. Policy settings continue to evolve. Weather variability, technology costs, and market behavior remain uncertain.
For Powerlink, the objective is not simply to produce a least-cost forecast. It is to provide decision-makers and stakeholders with credible, low-regret pathways that remain robust across a range of possible futures while minimizing total costs to consumers.
To support that objective, Powerlink has developed a layered, iterative long-term market modeling framework powered by PLEXOS® and scaled through PLEXOS® Cloud.
Traditional long-term models often generate a single optimized pathway based on defined assumptions. While analytically rigorous, this can obscure critical insight. Decision-makers need to understand not just what the model selects, but what drives those outcomes—and how sensitive they are to change.
Transmission planning adds additional complexity. Investments cannot be built incrementally. System operability must be validated beyond economic optimization. Deliverability constraints such as workforce availability and construction timing influence feasibility. Reliability must be preserved even under adverse operating conditions.
In this environment, Powerlink required a modeling approach that could:
The goal was a structured understanding of uncertainty—not a single deterministic forecast.
Powerlink’s process begins by clearly defining the planning questions the model is intended to answer. Those questions determine spatial resolution, temporal granularity, and core assumptions, ensuring the modeling effort remains decision focused.
Understanding the Energy Landscape with PLEXOS®
The first layer applies least-cost expansion modeling in PLEXOS® to explore a broad solution space. Investment options remain flexible, allowing planners to test how changes in costs, demand, and policy influence outcomes.
This phase focuses on understanding system drivers:
Rather than narrowing prematurely to a base case, Powerlink uses PLEXOS® to build insight into asset value and structural system dynamics. This establishes the foundation for identifying low-regret investments.
Layering in Real-World Constraints
Once drivers are understood, realism is progressively introduced.
Discrete transmission investments are modeled with defined timing and scale to reflect how projects are delivered. Different sequencing and sizing options are tested to move from theoretical least-cost builds to credible base cases.
Market modeling results are then iteratively validated through power system analysis to confirm operability. Where constraints emerge, those insights are fed back into PLEXOS® to better align economic outcomes with physical feasibility.
Deliverability constraints are also incorporated. Assumptions around construction capacity, timing limitations, and the ability to deliver multiple projects simultaneously ensure modeled pathways are achievable—not just optimal.
Testing Resilience with Lock-and-Shock
Optimization models inherently assume coordination and foresight that may not occur in practice. To address this, Powerlink developed a structured “lock-and-shock” analysis.
Modeled build pathways are locked in, and adverse but reasonable shocks, such as extreme weather or outages, are applied. The model is prevented from building additional capacity to resolve emerging issues.
This approach identifies potential supply gaps and quantifies the size, duration, and frequency of unserved energy events. Planners can then evaluate targeted, low-regret and least-cost remediation options.
By stress-testing modeled futures, Powerlink moves beyond hyper-optimization toward resilience-informed planning.
This layered methodology requires running large volumes of computationally intensive simulations. High temporal resolution, granular network representation, and extensive sensitivity testing significantly increase computing demands.
On-premises infrastructure can limit this type of analysis. PLEXOS® Cloud removes that constraint.
With PLEXOS® Cloud, Powerlink can:
Rather than restricting analysis due to computing limits, planners can fully explore modeling levers and test assumptions comprehensively.
PLEXOS® Cloud also integrates into Powerlink’s broader workflow architecture. Structured data extraction and transformation processes support model inputs, while version control and branching practices reduce the risk of human error. Inputs and outputs undergo disciplined quality assurance to ensure results are explainable and defensible.
Unexpected outcomes are examined rigorously. If results diverge from expectations, planners determine whether the cause lies in inputs or represents a valid system insight. This structured validation strengthens confidence in findings shared with decision-makers and stakeholders.
As Queensland’s energy system continues to evolve, credible planning depends on more than optimization. It requires understanding uncertainty, testing resilience, and identifying decisions that remain sound under changing conditions.
Powerlink’s layered framework delivers.
The framework enables identification of low-regret investments that retain value across a wide range of assumptions. It deepens understanding of system drivers, allowing planners to explain not just what the model selected, but why. It grounds long-term pathways in economic rigor, operational feasibility, and real-world deliverability.
PLEXOS® provides the analytical depth required to understand complex market dynamics. PLEXOS® Cloud enables that analysis to scale, reducing turnaround times and allowing more comprehensive testing.
The outcome is not a single definitive forecast, but a transparent, structured, and defensible planning process.