Hydro successfully produced aluminum using its new HalZero electrolysis technology for the first time. HalZero is a new primary aluminum production process that aims of achieving net-zero emissions.
“This is an important milestone for Hydro and Norway’s technology and research communities, and a significant step forward in the development of HalZero,” said Eivind Kallevik, president and CEO of Hydro. “Producing the first metal demonstrates the technology developed in partnership with leading Norwegian research institutions, including NTNU and SINTEF, works. It paves the way for the continued development, maturation, and testing of a technology with the potential to enable emission-free aluminum production in the future.”
Development of HalZero
Since 2016, Hydro’s technology teams have been working to develop HalZero, an entirely new process for producing primary aluminum. This development could replace the Hall–Héroult electrolysis technology, which was first patented in 1886 and is still the dominant industrial method for producing primary aluminum around the world. In the process, oxygen from alumina reacts with carbon anodes, generating CO2 emissions.
Hydro’s proprietary HalZero technology is based on converting alumina into aluminum chloride before electrolysis in a process designed to keep chlorine and carbon in closed loops. In the HalZero process, chlorine and carbon are kept in closed loops, enabling the process to eliminate CO2 emissions from electrolysis and anode production. The long-term ambition in developing this technology is to eliminate CO2 emissions from both electrolysis and anode production, releasing oxygen instead of CO2.
Hydro has now produced metal from aluminum chloride for the first time at its research and test facility at Herøya in Porsgrunn, Norway. The test facility was built with support from Enova, a state enterprise owned by the Norwegian Ministry of Climate and Environment, which awarded NOK 141 million (US$15 million) in 2023 for the construction and operation of the facility. The test center has been in operation since January 2026 and is being used to test the individual process steps in the HalZero technology.
Hydro has invested significant resources in developing HalZero over several years. Funds from the climate and energy component of Norway’s CO2 compensation scheme are also used to support this work. Further progress depends on using the test facility over the coming years for systematic learning, testing and continued technology development.
Further Development
As part of Hydro’s technology roadmap towards net-zero emissions, HalZero is a long-term technology development program and one of the company’s most demanding technology initiatives in decades. Producing the first metal represents a major step forward, although several years of targeted testing and piloting remain before the technology could be ready for industrial use.
The main HalZero processes are being tested at the Porsgrunn facility. The experience gained at the test center will provide the basis for further work on the industrial concept pilot and subsequent assessments of industrial scale deployment.
At this stage, production still generates CO2 emissions. The next step will focus on developing an industrial concept pilot, with the ambition of integrating and testing all the necessary process steps together.
The purpose of the pilot will be to establish the basis for the further industrial scaling of HalZero, with the aim of achieving net-zero emissions from primary aluminum production. Recently, Enova granted an additional NOK 82 million for the development of the project’s next phase, an industrial concept pilot for HalZero.
“Aluminum is a critical material for the energy transition and for transport, buildings, and infrastructure,” said Kallevik. “If the world is to succeed in reducing emissions, we must also transform the way aluminium is produced. Developing an entirely new technology is demanding and takes time, but Hydro has both the expertise and a responsibility to help move the aluminium industry forward. That is what we are working to achieve with HalZero.”