Rio Tinto Chooses Solar and Battery for Australian Smelter
In Australia, the debate over the transition to green energy has long been shrouded in uncertainty. While rooftop solar has proven beneficial for households and businesses, some sectors have highlighted the advantages of wind and solar energy contracts. However, skeptics continue to advocate for the reliability of fossil fuels, particularly coal power, dismissing the potential for renewables to take over. This outdated perspective is gradually being challenged by the decreasing costs of solar power and battery storage, coupled with the mounting scientific consensus on the urgent need to reduce emissions.
Recent developments indicate a shift towards renewables as Rio Tinto, Australia’s largest electricity consumer, opts for wind, solar, and battery storage to power its Queensland-based aluminium facilities. This strategic decision underscores the economic viability, reliability, and environmental benefits of renewable energy sources, ultimately safeguarding thousands of jobs in the Gladstone region.
Significance of Rio Tinto’s Renewable Energy Deal
Rio Tinto’s latest agreement with Edify Energy marks a significant milestone in the country’s renewable energy landscape. The deal involves the construction of a massive project combining 600 MW of solar capacity with 2,400 MWh of battery storage. This initiative not only represents the largest power purchase agreement signed by Rio Tinto but also addresses the critical need for “firming capacity” to support its industrial operations.
The innovative approach adopted by Edify Energy, known as “DC-coupled” design, integrates batteries within the solar arrays, eliminating the need for standalone facilities and reducing construction costs. This design optimally combines the cost-effectiveness of solar energy with the flexibility and dispatchability of batteries, offering a superior alternative to traditional AC-coupled hybrid systems.
Advantages of DC-Coupled Design
By utilising grid-forming inverters and minimising energy losses through direct DC feed, the DC-coupled design at Smoky Creek and Guthrie Gap projects enhances grid stability and efficiency. This configuration not only reduces plant losses but also mitigates grid constraints, ensuring a reliable and sustainable power supply for Rio Tinto’s operations.
Andrew Stiel, Edify Energy’s head of connections, emphasises the versatility of this design, enabling the power plant to operate efficiently throughout the day. The 4-hour battery capacity is strategically sized to meet peak demand periods, offering a cost-effective and environmentally friendly solution for energy-intensive industries.
Rio Tinto’s aluminium chief, Jérôme Pécresse, acknowledges the adaptability of smelters to various energy sources, provided a secure power supply is guaranteed. This shift towards renewables, supported by battery storage, signifies a progressive move away from coal-dependent operations, towards a more sustainable and resilient energy model.
With the declining costs of battery technology, the feasibility of “firm” solar energy at par with wind power has become a reality. The integration of batteries enables solar output to be stored and dispatched as needed, bridging the gap between utility-scale solar projects and rooftop installations.
Ultimately, Rio Tinto’s embrace of renewables and battery storage sets a precedent for other industrial players to follow suit. By prioritising commercial viability, reliability, and emission reductions, this transition underscores the growing acceptance of clean energy solutions in the mainstream market.
