As part of a pilot project, Audi is procuring 20-inch wheels for the Audi e-tron GT electric car that are made from low-CO2 emission aluminum supplied by Alcoa to RONAL GROUP, the wheel’s manufacturer. Alcoa is supplying aluminum for Audi’s pilot project from a self-developed, innovative smelting process that emits oxygen instead of carbon dioxide. The joint venture ELYSIS—formed by Alcoa and Rio Tinto in 2018 (earlier post)—is now further developing this process.
The ELYSIS smelting technology, which is currently being ramped up to a commerical scale with research in the US and Canada, causes no direct CO2 emissions when compared to the traditional process used to make aluminum.
The new smelting technology uses an inert anode that replaces the carbon anodes that are traditionally used during electrolysis, which is the process used to make primary aluminum. An inert anode is insoluble in the electrolyte under the conditions obtained in electrolysis.
For the manufacture of the Audi wheels, Alcoa is supplying the RONAL GROUP with a blend of metal from the ELYSIS process and Alcoa’s own low-carbon aluminum EcoLum (earlier post). EcoLum is delivered globally from predominantly hydro-powered smelters in North America and Europe.
The 20-inch aluminum alloy wheels from RONAL GROUP are used as an optional equipment variant for the model and produced using flow-forming technology for weight optimization.
The special propeller-shaped design of the rim improves the aerodynamic properties while driving. The mounted blades are just two to three millimeters thick, largely cover the wheels and thus help to ensure high aerodynamic efficiency.
As a gran turismo, the Audi e-tron GT was designed specifically for sportiness and efficiency, and it attains a drag coefficient of 0.24. This excellent value makes a significant contribution to the electric range of up to 488 or 472 kilometers (303 or 293 miles) according to the the WLTP.
The Audi e-tron GT is the first Audi electric car to be built in the Böllinger Höfe at the Neckarsulm site in Germany. The site has been supplied with renewable energy since 2020. Since the start of series production of the e-tron GT, a biogas-operated combined heat and power plant has been supplying the heat required for production in the Böllinger Höfe. Audi uses carbon credits from certified climate protection projects to offset CO2 emissions that currently cannot be avoided using renewable sources of energy.
The RONAL GROUP produces the rims at its location in Landau, using 100% eco-electricity, and compensates the heat consumption with biogas certificates.
Aluminum is the focus of our CO2 program because producing this material requires a high energy input. We are therefore actively searching for innovative processes that help reduce CO2 emissions as early as possible in the creation process. The process created by ELYSIS is promising because it already takes effect in the raw material processing phase. These kinds of innovations allow us to increase our sustainability performance in the supply chain and ensure that our models arrive at the customers with a smaller carbon footprint.—Marco Philippi, Audi AG’s Head of Procurement Strategy
Alcoa, Audi and the RONAL GROUP are members of the Aluminium Stewardship Initiative (ASI), the industry’s most comprehensive system for third-party certification of sustainable manufacturing practices. The global non-profit includes multiple stakeholders in its certification process, including producers, users, and civil society organizations. Alcoa has earned ASI’s Performance Standard and Chain of Custody certifications, allowing the Company to market and sell ASI-certified bauxite, alumina and aluminum.