US-headquartered Rondo Energy and global diversified miner Rio Tinto have started front-end engineering design (FEED) work on a 360 MWh energy storage project for deployment at the Yarwun alumina refinery near Gladstone, in Queensland.

The Rondo heat battery project is supported by an initial $3.6-million grant from the Australian Renewable Energy Agency (ARENA) for the FEED stage, with another $38-million having been committed by ARENA for deployment.

ARENA has also provided up to $33.3-million in conditional contingency support, which would only be made available in defined circumstances to manage specific project risks such as cost overruns and electricity costs.

Should the energy storage project conclude successfully, it will be one of the world's first large-scale demonstrations of thermal energy storage for industrial process heat and a world-first for the alumina industry.

Rondo heat batteries use abundant, low-cost midday electricity to charge, storing energy as high-temperature heat in refractory brick, and supply energy as 24/7 continuous process heat to industry. Typically, the heat is delivered as steam, directly into an industrial facility’s steam network.

Australia regularly has four to six hours of surplus solar-generated renewable electricity in the middle of the day, but industrial facilities need heat 24 hours a day, not just when the sun is shining.

By charging when electricity is cheap and abundant and discharging continuously, Rondo heat batteries turn short periods of low-cost electricity into 24/7 delivery of low-cost steam. 

For energy-intensive industries such as alumina refining, Rondo heat batteries create a pathway to electrification that addresses both emissions and energy costs.

"Because the heat battery slots into the existing steam network, the facility's processes run exactly as before — the only thing that changes is the energy for that heat: no longer from fossil fuels, but sourced from low cost electricity instead. The Yarwun study will assess the technical and economic viability of integrating the technology into refinery operations," Rondo Energy Australia head Kira Rundel confirms.

She adds that this project shows how Australia's abundant energy can become a competitive advantage for industry. 

"Heat batteries allow manufacturers to use low-cost electricity to produce the reliable, round-the-clock heat their operations need. Australia’s largest heat battery will show how factories can cut emissions without increasing energy costs, helping Australian industry to increase global competitiveness and supporting local manufacturing jobs.”

Rio Tinto pacific operations MD Armando Torres says reducing emissions from alumina refining is complex, particularly when it comes to generating the high-pressure steam needed for our operations.

“This study will help us determine whether thermal energy storage can provide a technically and economically viable alternative to fossil fuels for part of Yarwun’s steam requirements.

“The best way to tackle challenges of this scale is through collaboration between industry, government, and technology partners.  We welcome ARENA and Rondo’s support as we assess technologies that could help reduce our Scope 1 emissions while maintaining reliable operations at Yarwun," he concludes.