Rio teams with US manufacturer on ‘world first’ thermal energy storage project 

Rio Tinto and Rondo Energy have commenced engineering design on a 30 MW / 360 MWh thermal battery for the Yarwun alumina refinery in Queensland, supported by ARENA funding. The system stores electricity as high-temperature heat in refractory brick, delivering steam up to 1,000°C with claimed round-trip efficiency above 98%. If built, it would be among the first large-scale demonstrations of thermal storage for industrial process heat.

Where this fits

This project illustrates the cost and complexity of firming a renewable grid. Thermal batteries are a real tool for time-shifting cheap off-peak solar and wind into process heat on demand, which cuts fossil fuel use at the margin. But the economics depend entirely on a grid with abundant low-cost renewable surplus during sunny and windy hours, meaning it requires the massive transmission overbuild and battery fleet that a renewables-only system demands. The project validates the engineering; it does not solve the system-cost problem. It also depends on affordable grid electricity, which in turn depends on energy-dense baseload power to anchor prices and supply certainty.

What it means

Australia is doubling down on electrification of industry via time-shifted renewable surplus rather than investing in firm, low-emission generation that could deliver constant cheap heat without the need for storage infrastructure. A nuclear thermal plant would deliver the same industrial process heat on demand, with lower lifecycle emissions and no dependence on weather-synchronized grid dispatch. This project represents Australia's chosen path: storing renewable surplus to firm industry, rather than building the low-material, long-lived, firm generation that would require no storage at all.