The 'fantasy' underpinning Australia's rosy power supply forecasts - abc.net.au

An Australian energy analyst has characterised the grid forecasting assumptions underpinning government supply adequacy claims as "fantasy". The criticism centres on modelled behaviour of distributed solar and battery storage. The forecasts assume these resources will perform at levels inconsistent with real-world data when weather patterns tighten supply across the grid. Grid planners have built investment decisions and capacity margins on these optimistic assumptions.

Where this fits

This is a core reliability problem. Australia's renewable transition relies on weather-dependent sources. When forecasting assumes solar and batteries will deliver more than historical patterns support, planners underbuild firming capacity and transmission. The gap between forecast and fact is paid for later in higher costs, tighter margins, or both. The Energy Realism case rests on this pattern: renewables are cheap per megawatt, but whole-system costs, firming, overbuild, wasted assets, are under-counted because the models that justify investment assume away the hard parts.

What it means

Australia is building a grid on rosy assumptions about how weather-dependent capacity will behave under stress. When those assumptions fail to match reality, the grid either tightens (higher blackout risk) or requires expensive, rushed investment in gas peaking or batteries to bridge the gap. The honest way to close that gap is firm, dispatchable power. Nuclear is the lowest-emissions firm option and is legally banned. Instead, Australia will rely on natural gas as the firming backbone, locking in gas dependence and higher lifecycle emissions than a nuclear alternative would carry. A grid designed on forecast fantasy rather than observed physics is a security vulnerability.