Concentrated solar to provide carbon-free energy for mining
Rio Tinto, the world's second largest metals and mining corporation, has announced a partnership with Heliogen to explore the use of a breakthrough solar technology for mining operations in California.
Heliogen is a clean energy company that emerged from stealth mode in November 2019. Back then, it announced the first commercial use of concentrated solar with ultra-high temperatures greater than 1,000°C (1,832°F). This would be hot enough to replace the use of fossil fuels in many industrial processes, such as the production of cement, steel, and chemicals, dramatically reducing greenhouse gas emissions from these activities.
Worldwide, the mining industry today emits up to 5.1 gigatons of CO2 equivalent (CO2e) greenhouse gas (GHG) emissions annually – about 15 times more than natural releases from all undersea and land-based volcanoes on Earth. Rio Tinto has publicly acknowledged the reality of climate change for over two decades and has cut its emissions footprint by over 30% in the decade to 2020. It also divested the last of its coal businesses in 2018 and no longer extracts fossil fuels. However, there is still a long way to go in terms of reducing overall GHG emissions.
Rio Tinto has committed to spending $1 billion on emissions reduction initiatives globally by 2025. Its latest effort to become more sustainable is a partnership with Heliogen. Under a Memorandum of Understanding, Heliogen will deploy its artificial intelligence (AI)-powered technology at a borates mine in Boron, California, using heat from the Sun to enable the mine's industrial processes.
The site in question is California's largest open-pit mine and the largest borax mine in the world, producing nearly half the world's borates. Its ore reserves are sufficient for production through at least 2050.
Credits: Boron mine – by Marcin Wichary, CC BY 2.0.; satellite view – by NASA; borate mineral – by volkann.
Heliogen's high-temperature solar technology is designed to cost-effectively replace fossil fuels with sunlight for a range of industrial processes, including those used in mining. At Rio Tinto's Boron mine, the company's proprietary technology will use AI to control and optimise a network of mirrors that concentrate sunlight to capture energy used to make steam. Heliogen's system will also store the captured energy in the form of heat, allowing it to power night-time operations and provide the same uninterrupted energy offered by legacy fuels.
The operation at Boron extracts and refines borates into products ranging from fertilisers to construction materials and is producing lithium carbonate from a demonstration plant. The site currently generates steam using a natural gas cogeneration plant and natural gas-fired boilers. Heliogen's new installation will supplement these energy sources by generating up to 35,000 pounds per hour of steam to power operations, initially reducing carbon emissions by around 7% – equivalent to taking more than 5,000 cars off the road. Rio Tinto will then assess the potential for scaling-up the Heliogen technology to cover a larger proportion of activities at Boron, reducing the site's carbon footprint by as much as a quarter. If successful, it could eventually be deployed at many other mining operations around the world.
"This partnership with Heliogen has the potential to significantly reduce our emissions at Boron by using this groundbreaking solar technology, and we look forward to exploring opportunities across our global portfolio," said Jakob Stausholm, Rio Tinto CEO. "Addressing climate change effectively will require businesses, governments and society to work together through partnerships like this one, to explore innovative new solutions throughout the entire value chain. Our work with Heliogen is part of Rio Tinto's commitment to spend $1 billion on emissions reduction initiatives through to 2025 and our commitment to work with world-leading technology providers to achieve this goal."
"Since its founding, Heliogen has been laser-focused on decarbonising industrial sectors, including mining," said Bill Gross, Heliogen CEO & Founder. "As a result, this agreement with Rio Tinto is incredibly gratifying. We're pleased to find a partner committed to cutting its contributions to climate change. We're also pleased that Rio Tinto is exploring our technology to play an important role in helping reach its sustainability goals while dramatically reducing its energy costs.
"More broadly, we're excited to take this important step as we pursue Heliogen's goal of avoiding gigatons of CO2 emissions from the global economy by turning sunlight into an industrial energy source."
In April 2020, Fast Company nominated Heliogen for a "World Changing Ideas" award. The company won the Energy category. In November, TIME included Heliogen's technology on its Best Inventions of 2020 list.