Energy systems around the world are being asked to do more, with greater complexity, on tighter timelines. The old playbook of planning for peak demand, running synchronous generation, and keeping the lights on no longer cuts it anywhere.
At Energy Exemplar's Xcelerate 2026 conference in Sydney, Stewart Bell, Executive General Manager of Operations and Planning at Powerlink, was candid about the scale of that shift.
Powerlink owns and operates Queensland's transmission network, spanning 15,000 kilometers from the Gold Coast to Cairns and serving around five million customers. It's a large, geographically diverse grid deep in the energy transition, and a useful mirror for markets around the world … big or small.
For most of grid history, transmission planning came down to one question: can the network handle maximum demand?
Grid operators now need to plan simultaneously for maximum demand, minimum demand, and low-generation weather events.
In Queensland, the duck curve is no longer theoretical. Rooftop solar now sits on roughly half of all households, squeezing the space available for synchronous coal generation during low-demand periods from around 4,500 MW to approximately 2,500 MW. Minimum demand has quietly become a reliability problem, and peak-only planning frameworks are already behind.
Adding wind and solar doesn't just shift the generation mix; it changes how the grid behaves. Averages look manageable, and edge cases are where reliability is won or lost.
Queensland now has 50 renewable and storage projects connected or underway. Wind tending to blow at night and solar generating during the day gives the state a natural geographic advantage, backed by two diverse wind systems. But that diversity doesn't eliminate the risk of a windless, overcast June day where solar output peaks at 20% and four-hour batteries are depleted by afternoon.
Every market has its own version of this risk, sometimes called Dunkelflaute — extended periods of low wind and low solar that stress even well-resourced grids. Understanding your grid's specific weather risk profile is not optional; it's foundational.
Battery storage is scaling rapidly, and there's a temptation to treat it as the solution to intermittency. The modeling tells a more nuanced story.
Queensland has seen around 3 GW of batteries connect to its network in just 18 months, with another 1.5 GW underway. Yet when Powerlink modeled 175 GWh of storage against historical weather data, they found that in a poor weather year, that storage could be exhausted three times over within a single month. As Bell put it: "No matter how much storage you have, you will still need the gas turbines."
The required capacity of firm backup stays relatively stable — the megawatts don't change much, but the run hours do. Ireland has already grappled with this, with its government procuring around 640 MW of gas turbines held outside the market as a strategic reserve. As Bell observed, "this just becomes an insurance product that has to be bought outside the market,” an early signal of where other markets may be heading.
Energy transition planning is only as good as the inputs underneath it. Markets move fast, and assumptions that were reasonable five years ago may be significantly off today.
Powerlink uses PLEXOS® to run an iterative, layered market modeling process, producing inter-temporal dynamic forecasts at 30-minute resolution across multiple weather years. That capability helped underpin the Queensland Government's Energy Roadmap, and two Queensland transition points are flagged green on the national system security plan, a concrete indicator that forward-looking modeling translates into real planning outcomes.
But Bell was direct about the limits: five years ago, the same modeling was built around significant hydrogen demand and a major 5 GW pumped hydro project. Both have since been substantially wound back. The market moved, and the models had to follow.
PLEXOS ®, Energy Exemplar's market modeling platform, is built for exactly this kind of complexity, giving grid operators and planners the analytical firepower to make confident, least-regret decisions in a rapidly changing energy landscape.
Queensland's experience points to a set of principles that apply well beyond its borders: plan for multiple operating scenarios, not just peak demand; understand your grid's specific weather risk, including the tail events; size firm backup for a bad weather year, not the average; and keep modeling iteratively and close to the market.
System security is the next hard problem. Synchronous condensers, gas turbines with clutches, and grid-forming batteries are the emerging toolkit, but getting grid-forming batteries to deliver base-level system stability at scale remains an open challenge for operators worldwide.
The energy transition is moving at different speeds in different markets, but the underlying challenges are consistent. The question for grid operators and planners everywhere isn't whether the framework needs to evolve, it's whether it already has. Getting there starts with modeling that keeps pace with reality, and the discipline to act on what it tells you.